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KRNL - An Arduino Kernel
Last update: 260414 14:36:38
Browse files incl examples:
Src folder list: here
Download zipfile for install krnl/krnl.zip
Doxified krnl here: html/index.html
Github: https://github.com/jdn-aau/krnl
I have found it interesting to develop an open source realtime kernel (KRNL) for the Arduino platform:
open source
well suited for teaching
easy to read and understand source
priority to straight code instead insane optimization(which will make it nearly unreadable)
well suited for serious duties - but with no warranty what so ever
easy to use
just import library krnl and you are ready
automatic recognition of architeture
supports all atmega variants I have had available (168,328,1280,2560 - uno, duemillanove, mega 1280 and 2560)
Suited for scheduability test after RMA
Krnl traps miss of deadlines and issue a breakout to user space so ypu can trap
Some characteristics:
preemptive scheduling
Basic heart beat at 1 kHz. KRNL can have heeartbeat in quants of milli seconds
krnl uses timer2 so PWM based on timer2 is not possible(you can change it)
static priority scheme
support task, semaphores, message queues
All elements shall be allocated prior to start of KeRNeL
support user ISRs and external interrupts
Directory krnl shall be within your libraries directory .. sketchbook/libraries
You have to restart your arduino environment
See templates for a number of commented runable examples which illustrates very well different mockups.
Access to code
welcome
history
krnl on github download as zipfile or clone it
git clone https://github.com/jdn-aau/krnl.git
( 2018 added immediate ceiling protocol on semaphores (version 20180313)
( updated june 2015 with new features for handling tight fixed frequency execution)
krnl consists of two files krnl.h and krnl.cpp which you shall save in directory sketchbook/libraries/krnl
Src folder list: here
or click here - beware wuite many lines of code
/*******************************************************
* *
* *
* | |/ /___| _ \| \ | | ___| | *
* | ' // _ \ |_) | \| |/ _ \ | *
* | . \ __/ _ <| |\ | __/ |___ *
* |_|\_\___|_| \_\_| \_|\___|_____| *
* *
* *
* you are watching krnl.c *
* *
* March 2015,2016,..,2018 *
* Author: jdn *
* final sep 2022 *
* *
* this version adapted for Arduino
*
* (C) 2012,2013,2014
* 2017,2018,2019,2021,2022,2023
*
*
* IF YOU ARE LUCKY LOOK HERE
*
* https://github.com/jdn-aau/krnl
*
*
*
* Jens Dalsgaard Nielsen <jdn@es.aau.dk>
* http://es.aau.dk/staff/jdn
* Section of Automation & Control
* Aalborg University,
* Denmark
*
* "THE BEER-WARE LICENSE" (frit efter PHK)
* <jdn@es.aau.dk> wrote this file. As long as you
* retain this notice you can do whatever you want
* with this stuff. If we meet some day, and you think
* this stuff is worth it ...
* you can buy me a beer in return :-)
* or if you are real happy then ...
* single malt will be well received :-)
*
* Use it at your own risk - no warranty
*
* nice info...
* http://www.nongnu.org/avr-libc/user-manual/FAQ.html#faq_cplusplus
* at 20090611
* - k_eat_time now eats time in quants of krnl tick speed but not one quant
*boundary
* - added k_malloc and k_free
* k_free dont free memory bq we do not want fragmentation
* so DONT USE k_free. I do NOT free memory
* - k_malloc and k_free are weak functions so you can just add your own
*versions
* - watchdog is enabled (2sec and reset in krnl timer) in weak function
*k_enable_wdt
*
* remember to update in krnl.c !!!
*****************************************************/
#define KRNL_VRS 20240525
#ifndef KRNL
#define KRNL
// IMPORTANT DEFINES !!!!
// IMPORTANT DEFINES !!!!
// IMPORTANT DEFINES !!!!
// IMPORTANT DEFINES !!!!
// IMPORTANT DEFINES !!!!
#define KRNLBUG // KRNLBUG ACTIVATE BREAK OUT FUNCTIONS
// BACKSTOPPER wraps a looping fct around your task so it will just restart
// like loop function
// BEWARE bq local variables in the task body just evaporate - as always
#define BACKSTOPPER
// if you want to use k_malloc
// NB k_free wont release mem due to possible fragmentation
// SO DONT USE k_free its just a fake
// NEVER !!! free men in a rt system...
// and please do all malloc before starting running
#define DYNMEMORY
// DON NOT CHANGE K_TICK - must be 1 millisec
#define K_TICK 1
// if defined you will stop in backstopper, else you will jump back to task s
// see comments about local vars above
//#define STOP_IN_BACKSTOPPER
//#define WDT_TIMER
#define WDT_PERIOD WDTO_1S
// IF YOU WANT READER WRITER LOCK THEN DEFINE
// experimental - no guarantee
//https://www.geeksforgeeks.org/readers-writers-problem-writers-preference-solution/?ref=rp
//https://www.geeksforgeeks.org/readers-writers-problem-set-1-introduction-and-readers-preference-solution/
// https://www.tutorialspoint.com/readers-writers-problem
//#define READERWRITER
// Define watchdog timer and period
// if you enable it it will be running at once
// END IMPORTANT DEFINES
// END IMPORTANT DEFINES
// END IMPORTANT DEFINES
// END IMPORTANT DEFINES
// END IMPORTANT DEFINES
// END IMPORTANT DEFINES
// SELECTION OF HW TIMER TO BE USED FOR krnl tick
// SELECTION OF HW TIMER TO BE USED FOR krnl tick
// SELECTION OF HW TIMER TO BE USED FOR krnl tick
// Reverted to use only timer 2
//HAS IMPACT ON PWM !!!! SEE BELOW !!!
#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__) \
|| defined(__AVR_ATmega2561__) || defined(__AVR_ATmega1284P__)\
|| defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328PB__)\
|| defined(__AVR_ATmega328__)
#define KRNLTMR 2
#elif defined(__AVR_ATmega32U4__)
//#define KRNLTMR 3
#error "32u4 hmm AVR cpu type - bad place to come"
#else
#error "unknown AVR cpu type - bad place to come"
#endif
/***********************
NB NB ABOUT WRAP AROUND
Krnl maintain a milisecond timer (k_millis_counter)
It s 32 bit unsigned long so it wraps around after 49.7 days.
As all timing internal in krnl is relative (from now) then
wrap around will have no influence on krnl !!!fk_eat
NB NB ABOUT TIMERS PORTS ETC
You can configure krnl to use timer 1,2,3,4,5
If you want to use timer 0 then you need to
- set KRNLTMR = 0 just below in USER CONFIGURATION PART
- mangle with Arduino library code in ...
hardware/arduino/avr/cores/arduino/wiring.c
rename ISR ... with function head:
#if defined(__AVR_ATtiny24__) || defined(__AVR_ATtiny44__) ||
defined(__AVR_ATtiny84__) ISR(TIM0_OVF_vect) #else ISR(TIMER0_OVF_vect) #endif
to something else : mayby void kurt()
This is because krnl install an ISR on timer0 and there cant be two
Krnl to maintain the millis counters so everything with millis, micros etc is
as usual.
Buth normally you cant use timer 0 bq it is used for millis and preallocated.
See below
When using a timer you must be aware of that it will prohibit you from things
like
- tone (pwm sound) uses timer2
... from http://blog.oscarliang.net/arduino-timer-and-interrupt-tutorial/
Timer0:
- 8bit timer.
- In the Arduino world Timer0 is been used for the timer functions, like
delay(), millis() and micros().
- If you change Timer0 registers, this may influence the Arduino timer
function.
- So you should know what you are doing.
- 16bit timer.
- In the Arduino world the Servo library uses Timer1 on Arduino Uno (Timer5
on Arduino Mega).
Timer2:
- 8bit timer like Timer0.
- In the Arduino world the tone() function uses Timer2.
Timer3 16 bits
- 1280/1284P and 2560 only
Timer4, Timer5 16 bits
- 1280 and 2560 only
On Uno
- Pins 5 and 6: controlled by timer0
- Pins 9 and 10: controlled by timer1
- Pins 11 and 3: controlled by timer2
On the Arduino Mega we have 6 timers and 15 PWM outputs:
TODO pinout below need checkup
- Pins 4 and 13: controlled by timer0
- Pins 11 and 12: controlled by timer1
- Pins 9 and10: controlled by timer2
- Pin 2, 3 and 5: controlled by timer 3
- Pin 6, 7 and 8: controlled by timer 4
- Pin 46, 45 and 44:: controlled by timer 5
... from http://arduino-info.wikispGitte Merete
Holm-Pedersenaces.com/Timers-Arduino
- Servo Library uses Timer1.
-- You can’t use PWM on Pin 9, 10 when you use the Servo Library on an
Arduino.
-- For Arduino Mega it is a bit more difficult. The timer needed depends on
the number of servos.
-- Each timer can handle 12 servos.
-- For the first 12 servos timer 5 will be used (losing PWM on Pin 44,45,46).
-- For 24 Servos timer 5 and 1 will be used (losing PWM on Pin
11,12,44,45,46)..
-- For 36 servos timer 5, 1 and 3 will be used (losing PWM on Pin
2,3,5,11,12,44,45,46)..
-- For 48 servos all 16bit timers 5,1,3 and 4 will be used (losing all PWM
pins).
- Pin 11 has shared functionality PWM and MOSI.
-- MOSI is needed for the SPI interface, You can’t use PWM on Pin 11 and the
SPI interface at the same time on Arduino.
-- On the Arduino Mega the SPI pins are on different pins.
- tone() function uses at least timer2.
-- You can’t use PWM on Pin 3,11 when you use the tone() function an Arduino
and Pin 9,10 on Arduino Mega.
SO BEWARE !!!
PERFORMANCE
std internal speed 1 kHz
Rudimentary prog with one task the timer ISR takes about 21 usec
Uno, leonardo and mega measures the same
period:
timer0 1024 usec for 1 msec ...
timer1,2,3... 1007 usec for 1 msec
>>>>>>>>>>>>
MODIFY OF/hardware/arduino/avr/cores/arduino/wiring.c
I have added the MOD part (MOD: modification)
So if you go for timer0
1)remove the // in front of #define MOD
2) change here in krnl.h KRNLTMR to 0 for your architecture
ONLY SUPPORT FOR AVR's (uno,leonardo,nano,mega,...)
//#define MOD
MAY WORK OR NOT !!!! BEWARE /Jens
#if defined (MOD)
void justFakeFctHead()
#else
#if defined(__AVR_ATtiny24__) || defined(__AVR_ATtiny44__) ||
defined(__AVR_ATtiny84__) ISR(TIM0_OVF_vect) 769769876987 lalalalalalal #else
ISR(TIMER0_OVF_vect)
#endif
#endif
>>>>>>>>>>>>
***********************************************************/
// set bit clear bit
#ifndef sbi
#define sbi(r, b) r |= _BV(b)
#endif
#ifndef cbi
#define cbi(r, b) r &= ~_BV(b)
#endif
#ifndef rbi
#define cbi(r, b) r &= ~_BV(b)
#endif
// >>>>>>>>>>>>>>>>> USER CONFIGURATION PART <<<<<<<<<<<<<<<<<<
// We do use a char forholding prio so ax max interval is 0 -> 127
// as Qheads has lowest prio we here have the limit 0-99 for tasks
// see below
#define QHD_PRIO 102 // Queue head prio - for sentinel use
#define ZOMBI_PRIO (QHD_PRIO - 1)
#define DMY_PRIO (QHD_PRIO - 2) // dummy task prio (0 == highest prio)
// no real dummytask - we do use ya old mmin loop "task""
#define DMY_STK_SZ 90 // staksize for dummy
#define STAK_HASH 0x5c // just a hashcode
#define MAX_SEM_VAL 30000 // NB is also max for nr elem in msgQ !
#define MAX_INT 0x7FFF
#define CEILINGFAILNOTCEIL -3
#define CEILINGFAILPRIO -4
/* which timer to use for krnl heartbeat
timer 0 ( 8 bit) is normally used by millis - avoid !
timer 1 (16 bit)
timer 2 ( 8 bit) not 32u4
timer 3 (16 bit) 32u4/1280/1284p/2560 only
timer 4 (16 bit) 1280/2560 only (MEGA)
timer 5 (16 bit) 1280/2560 only (MEGA)
*/
// END USER CONFIGURATION
//----------------------------------------------------------
#ifdef __cplusplus
extern "C" {
#endif
/***** KeRNeL data types *****/
struct k_t {
#ifdef BACKSTOPPER
void (*pt)(void);
#endif
unsigned char nr;
struct k_t *next, // task,sem: double chain lists ptr
*pred; // task,sem: double chain lists ptr
volatile char sp_lo, // sem:vacant | task: low 8 byte of stak adr
sp_hi; // sem: vacant |task: high 8 byte of stak adr
char prio, // task & sem: priority
ceiling_prio, // sem
saved_prio; // semaohore
volatile int cnt1, // sem: sem counter | task: ptr to stak
cnt2, // asem: dyn part of time counter | task: timeout
cnt3, // sem: preset timer value | task: ptr to Q we are hanging in
maxv, // sem: max value | task: org priority
clip; // sem: counter for lost signals | task: vacant
};
extern unsigned char k_coopFlag;
struct k_msg_t {
// msg type
unsigned char nr;
struct k_t *sem;
char *pBuf; // ptr to user supplied ringbuffer
volatile int nr_el, el_size, lost_msg;
volatile int r, w, cnt;
};
#ifdef READERWRITER
struct k_rwlock_t {
int nrReaders;
struct k_t *rdwrSem, *rdSem, *fifoSem;
};
#endif
/***** KeRNeL variables *****/
// keep track of k alloc
extern int k_task, k_sem, k_msg;
extern volatile char krnl_preempt_flag;
extern char dmy_stk[DMY_STK_SZ];
extern volatile char k_wdt_enabled;
// QUEUES
extern struct k_t *task_pool, *sem_pool, AQ, // activeQ
*pmain_el, *pAQ, *pDmy, // ptr to dummy task descriptor
*pRun, // ptr to running task
*pSleepSem;
extern struct k_msg_t *send_pool;
extern char nr_task, nr_sem, nr_send;
extern volatile char k_running; // no running
extern volatile char k_err_cnt; // every time an error occurs cnt is incr by one
extern unsigned long k_millis_counter;
extern char k_preempt_flag;
/******************************************************
MACROS MACROS
PUSHREGS AND POPREGS
is actual staklayout plus task address at top
A push/pop takes 2 cycles
a call takes 3 cycles
ret/iret 3-4 cycles
So a PUSHREGS is 33 instructions(@ 2 cycles) = 66 cycles ~= 66 cycles /"16
MHz" ~= 4.1 usec So an empty iSR which preserves all registers takes 2*4.1usec +
8-10 cycles (intr + iret) ~= 9 usec So max isr speed with all regs saved is
around 100 kHz but then with no code inside ISR !
WARNING
The 2560 series has 3 bytes PC the rest only 2 bytes PC !!! (PC. program
counter) and no tall has rampz and eind register
REGISTER NAMING AND INTERNAL ADRESSING
https://en.wikipedia.org/wiki/Atmel_AVR_instruction_set
http://www.rjhcoding.com/avr-asm-io.php
Register I/O address Data address
SREG 0x3F 0x5F
SP 0x3E:0x3D 0x5E:0x5D
EIND 0x3C 0x5C
RAMPZ 0x3B 0x5B
RAMPY 0x3A 0x5A
RAMPX 0x39 0x59
RAMPD 0x38 0x58
A typical ATmega memory map may look like:
Data address I/O address Contents
0x0000 – 0x001F Registers R0 – R31
general purpose regs
r0 mem addr
...
0 0 0x0000
1 1 0x0001
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
a 10
b 11
c 12
d 13
e 14
f 15
10 16
11 17
12 18
13 19
14 20
15 21
16 22
17 23
18 24
19 25
1a 26 Xref L
1b 27 Xreg H
1c 28 Yreg L
1d 29 Yreg H
1e 30 Zreg L
1f 31 Zreg H 0x001F
0x0020 – 0x003F 0x00 – 0x1F I/O registers (bit-addressable)
0x0040 – 0x005F 0x20 – 0x3F I/O registers (not bit-addressable)
0x0060 – 0x00FF Extended I/O registers (memory-mapped I/O only)
0x0100 – RAMEND Internal SRAM
Register addresses
IO adr data addr
0x3f SREG 0x5f
0x3e SPH
0x3d SPL
0x3c EIND 0x5c 1280/2560 only
0x3b RAMPZ 0x5b 1280/2560/1284p only
...
0x1f R31
etc
0x01 R1
0x00 R0
PC is NOT available
*/
#define lo8(X) ((unsigned char)((unsigned int)(X)))
#define hi8(X) ((unsigned char)((unsigned int)(X) >> 8))
#define DI() __asm__ volatile("cli")
#define EI() __asm__ volatile("sei")
#define RETI() __asm__ volatile("reti")
extern volatile char k_bug_on;
// IF KRLBUG IS DEFINED THEN breakout is called for every time a taskshift appears
// IF KRLBUG IS DEFINED THEN breakout is called for every time a taskshift appears
#ifdef KRNLBUG
#define K_CHG_STAK() \
\
if (pRun != AQ.next) { \
pRun->sp_lo = SPL; \
pRun->sp_hi = SPH; \
pRun = AQ.next; \
k_breakout(); \
SPL = pRun->sp_lo; \
SPH = pRun->sp_hi; \
}
#else
#define K_CHG_STAK() \
if (pRun != AQ.next) { \
pRun->sp_lo = SPL; \
pRun->sp_hi = SPH; \
pRun = AQ.next; \
SPL = pRun->sp_lo; \
SPH = pRun->sp_hi; \
}
#endif
/* below: r1 must/shall always assumed to be zero in c code (gcc issue I think)
*/
// AVR / ARDUINO PART PUSH POP
// 0x3b RAMPZ extended z-pointer register
// 0x3c EIND extended indirect register
/* below: r1 must/shall always assumed to be zero in c code (gcc issue I think)
*/
#if defined(__AVR_ATmega2560__) || defined(__AVR_ATmega1280__) || \
defined(__AVR_ATmega2561__)
// 0x3b RAMPZ extended z-pointer register
// 0x3c EIND extended indirect register
#define PUSHREGS() \
__asm__ volatile("push r1 \n\t" \
"push r0 \n\t" \
"in r0, __SREG__ \n\t" \
"cli \n\t" \
"push r0 \n\t" \
"in r0 , 0x3b \n\t" \
"push r0 \n\t" \
"in r0 , 0x3c \n\t" \
"push r0 \n\t" \
"clr r1 \n\t" \
"push r2 \n\t" \
"push r3 \n\t" \
"push r4 \n\t" \
"push r5 \n\t" \
"push r6 \n\t" \
"push r7 \n\t" \
"push r8 \n\t" \
"push r9 \n\t" \
"push r10 \n\t" \
"push r11 \n\t" \
"push r12 \n\t" \
"push r13 \n\t" \
"push r14 \n\t" \
"push r15 \n\t" \
"push r16 \n\t" \
"push r17 \n\t" \
"push r18 \n\t" \
"push r19 \n\t" \
"push r20 \n\t" \
"push r21 \n\t" \
"push r22 \n\t" \
"push r23 \n\t" \
"push r24 \n\t" \
"push r25 \n\t" \
"push r26 \n\t" \
"push r27 \n\t" \
"push r28 \n\t" \
"push r29 \n\t" \
"push r30 \n\t" \
"push r31 \n\t")
#define POPREGS() \
__asm__ volatile("pop r31 \n\t" \
"pop r30 \n\t" \
"pop r29 \n\t" \
"pop r28 \n\t" \
"pop r27 \n\t" \
"pop r26 \n\t" \
"pop r25 \n\t" \
"pop r24 \n\t" \
"pop r23 \n\t" \
"pop r22 \n\t" \
"pop r21 \n\t" \
"pop r20 \n\t" \
"pop r19 \n\t" \
"pop r18 \n\t" \
"pop r17 \n\t" \
"pop r16 \n\t" \
"pop r15 \n\t" \
"pop r14 \n\t" \
"pop r13 \n\t" \
"pop r12 \n\t" \
"pop r11 \n\t" \
"pop r10 \n\t" \
"pop r9 \n\t" \
"pop r8 \n\t" \
"pop r7 \n\t" \
"pop r6 \n\t" \
"pop r5 \n\t" \
"pop r4 \n\t" \
"pop r3 \n\t" \
"pop r2 \n\t" \
"pop r0 \n\t" \
"out 0x3c , r0 \n\t " \
"pop r0 \n\t" \
"out 0x3b , r0 \n\t " \
"pop r0 \n\t" \
"out __SREG__ , r0 \n\t " \
"pop r0 \n\t" \
"pop r1 \n\t")
#elif defined(__AVR_ATmega1284P__)
// 0x3b RAMPZ extended z-pointer register
// 0x3c EIND extended indirect register
#define PUSHREGS() \
__asm__ volatile("push r1 \n\t" \
"push r0 \n\t" \
"in r0, __SREG__ \n\t" \
"cli \n\t" \
"push r0 \n\t" \
"in r0 , 0x3b \n\t" \
"push r0 \n\t" \
"clr r1 \n\t" \
"push r2 \n\t" \
"push r3 \n\t" \
"push r4 \n\t" \
"push r5 \n\t" \
"push r6 \n\t" \
"push r7 \n\t" \
"push r8 \n\t" \
"push r9 \n\t" \
"push r10 \n\t" \
"push r11 \n\t" \
"push r12 \n\t" \
"push r13 \n\t" \
"push r14 \n\t" \
"push r15 \n\t" \
"push r16 \n\t" \
"push r17 \n\t" \
"push r18 \n\t" \
"push r19 \n\t" \
"push r20 \n\t" \
"push r21 \n\t" \
"push r22 \n\t" \
"push r23 \n\t" \
"push r24 \n\t" \
"push r25 \n\t" \
"push r26 \n\t" \
"push r27 \n\t" \
"push r28 \n\t" \
"push r29 \n\t" \
"push r30 \n\t" \
"push r31 \n\t")
#define POPREGS() \
__asm__ volatile("pop r31 \n\t" \
"pop r30 \n\t" \
"pop r29 \n\t" \
"pop r28 \n\t" \
"pop r27 \n\t" \
"pop r26 \n\t" \
"pop r25 \n\t" \
"pop r24 \n\t" \
"pop r23 \n\t" \
"pop r22 \n\t" \
"pop r21 \n\t" \
"pop r20 \n\t" \
"pop r19 \n\t" \
"pop r18 \n\t" \
"pop r17 \n\t" \
"pop r16 \n\t" \
"pop r15 \n\t" \
"pop r14 \n\t" \
"pop r13 \n\t" \
"pop r12 \n\t" \
"pop r11 \n\t" \
"pop r10 \n\t" \
"pop r9 \n\t" \
"pop r8 \n\t" \
"pop r7 \n\t" \
"pop r6 \n\t" \
"pop r5 \n\t" \
"pop r4 \n\t" \
"pop r3 \n\t" \
"pop r2 \n\t" \
"pop r0 \n\t" \
"out 0x3b , r0 \n\t " \
"pop r0 \n\t" \
"out __SREG__ , r0 \n\t " \
"pop r0 \n\t" \
"pop r1 \n\t")
#elif defined(__AVR_ATmega168__) || defined(__AVR_ATmega328P__) || defined(__AVR_ATmega328PB__) \
|| defined(__AVR_ATmega328__) || defined(__AVR_ATmega32U4__)
#define PUSHREGS() \
__asm__ volatile("push r1 \n\t" \
"push r0 \n\t" \
"in r0, __SREG__ \n\t" \
"cli \n\t" \
"push r0 \n\t" \
"clr r1 \n\t" \
"push r2 \n\t" \
"push r3 \n\t" \
"push r4 \n\t" \
"push r5 \n\t" \
"push r6 \n\t" \
"push r7 \n\t" \
"push r8 \n\t" \
"push r9 \n\t" \
"push r10 \n\t" \
"push r11 \n\t" \
"push r12 \n\t" \
"push r13 \n\t" \
"push r14 \n\t" \
"push r15 \n\t" \
"push r16 \n\t" \
"push r17 \n\t" \
"push r18 \n\t" \
"push r19 \n\t" \
"push r20 \n\t" \
"push r21 \n\t" \
"push r22 \n\t" \
"push r23 \n\t" \
"push r24 \n\t" \
"push r25 \n\t" \
"push r26 \n\t" \
"push r27 \n\t" \
"push r28 \n\t" \
"push r29 \n\t" \
"push r30 \n\t" \
"push r31 \n\t")
#define POPREGS() \
__asm__ volatile("pop r31 \n\t" \
"pop r30 \n\t" \
"pop r29 \n\t" \
"pop r28 \n\t" \
"pop r27 \n\t" \
"pop r26 \n\t" \
"pop r25 \n\t" \
"pop r24 \n\t" \
"pop r23 \n\t" \
"pop r22 \n\t" \
"pop r21 \n\t" \
"pop r20 \n\t" \
"pop r19 \n\t" \
"pop r18 \n\t" \
"pop r17 \n\t" \
"pop r16 \n\t" \
"pop r15 \n\t" \
"pop r14 \n\t" \
"pop r13 \n\t" \
"pop r12 \n\t" \
"pop r11 \n\t" \
"pop r10 \n\t" \
"pop r9 \n\t" \
"pop r8 \n\t" \
"pop r7 \n\t" \
"pop r6 \n\t" \
"pop r5 \n\t" \
"pop r4 \n\t" \
"pop r3 \n\t" \
"pop r2 \n\t" \
"pop r0 \n\t" \
"out __SREG__ , r0 \n\t " \
"pop r0 \n\t" \
"pop r1 \n\t")
#else
#error "unknown arch"
#endif
// function prototypes
// naming convention
// k_... function do a DI/EI and can impose task shift
// ki_... expects interrupt to be disablet and do no task shift
// rest is internal functions
#ifdef DYNMEMORY
/**
call malloc protected by DI and EI
if dft as weak so you can supply with your own
*/
void *k_malloc(int k);
/**
call free
empty - no function
if dft as weak so you can supply with your own
@remark do no free mem bq we do not want fragmented memory
*/
void k_free(void *m);
#endif
/**
* Call wdt_enable (AVR lib)
* DI();
* wdt_enable(WDT_PERIOD);
* EI();
* WDT_PERIOD is in KRNL i sec
* @param[t] watchdog timout WDT_PERIOD is 1 sec
* See avrlib docu for more info
* The watchdog is reset in krnls timer ISR when active
*/
void __attribute__((weak)) k_wdt_enable(int t);
/**
* disable wdt
* Disable the watchdog timer
*/
void __attribute__((weak)) k_wdt_disable();
/**
Returns nr of milliseconds since krnl was started by k_start
@return: unsigned long is returned
@remark only to be called after start of KRNL and only when interrupt is
disabled
@remark To be called within an ISR so interrupts is no disabled
*/
unsigned long ki_millis(void);
/**
Return krnl ticksize
As for now it can be 1 (msec) or 10(msec)
BEWARE All delays are in quants of tick_size..
*/
int k_ticksize(void);
/**
Returns nr of milliseconds since krnl was started by k_start
@return: unsigned long is returned
@remark only to be called after start of KRNL
@remark Interrupt is disabled when reading krnl time and is enabled
afterwards
*/
unsigned long k_millis(void);
/**
* Eat time in quant of krnl ticks
* starting from now but not from next tick
* Eats CPU time in k_tick quants
@param[in] tyick number of ticks to eat
*/
void k_eat_msec(unsigned int eatTime);
/**
issues a task shift - handle with care
Not to be used by normal user
*/
void ki_task_shift(void) __attribute__((naked));
/**
Set task asleep for a number of ticks.
@param[in] time nr of ticks to sleep < 0
@return: 0 is ok(has been suspended), 1(is not suspended), -1 is wait time
is less than 0
@remark only to be called after start of KRNL
*/
int k_sleep(int time);
/**
creates a task and put it in the active Q
@param[in] pTask pointer to function for code ( void task(void) ...)
@param[in] stkSize size of data area(in bytes) to be used for stak
@param[in] prio - task prio max: 1 lowest < DUMMY_PRIO
@return: pointer to task handle or NULL if no success
@remark only to be called before start of KRNL but after k_init
*/
struct k_t *k_crt_task(void (*pTask)(void), char prio, char *pS, int stkSize);
/**
change priority of calling task)
@param[in] prio new prio, Priority 1: highest (QHEAD_PRIO-1): lowest
@return: 0: ok, -1: KRNL not running, -2: illegal value
@remark only to be called after start of KRNL
*/
int k_set_prio(char prio);
/**
creates a standard Dijkstra semaphore. It can be initialized to values in
range [0..maxvalue]
@param[in] init_val startvalue of semaphore 0,1,2,... maxvalue
@param[in] maxvalue which is maxvalue semaphore can reach
@return handle to semaphore or NULL pointer
@remark only to be called before start of KRNL
*/
struct k_t *k_crt_sem(int init_val, int maxvalue);
/**
adds ceiling priority to semaphore
use k_mut_ceil_enter k_mut_ceil_leave instead of wait and signal
Can only be called before k_start
@param[in] sem reference to sem used for mutex - no check
@param[in] prio Ceiling pirority
@return 0: ok , otherwise bad bad
@remark only to be called before start of KRNL
*/
/**
creates a standard mutex. It can be initialized to values in range
[0..maxvalue]
@param[in] init_val startvalue of semaphore 0,1,2,... maxvalue
@param[in] maxvalue which is maxvalue semaphore can reach
@return handle to semaphore or NULL pointer
@remark only to be called before start of KRNL
*/
struct k_t *k_crt_mut(char ceiling_prio, int init_val, int maxvalue);
int k_mut_ceil_set(struct k_t *sem, char prio);
/**
Enter mutex (eq to k_wait...)
use k_mut_enter / k_mut_leave instead of wait and signal
@param[in] sem aka mutex
@param[in] timeout timeout value
@return 0: if you have been waiting, 1 if you just went through, -1 for
timeout, -3 if your priority was higher than ceiling priority
*/
int k_mut_ceil_enter(struct k_t *sem, int timeout);
/**
Leave mutex (eq to k_signal...)
use k_mut_enter/ k_mut_leave instead of wait and signal
@param[in] sem used as mutex
@return 0: ok otherwise bad bad
*/
int k_mut_ceil_leave(struct k_t *sem);
/**
Mutex enter and leave w imm priority ceiling in one operation
@param sm mutex with ceiling
@param timeout 0 == forever
@fct void fct(void) the function w critical code
@return 0: ok ,waited, 1 straight through; -1 timeout, -3 CEILINGFAILNOTCEIL
not a semaphore w ceiling, -4 CEILINGFAIL my priority is above ceil max prio
*/
int k_mut_ceil(struct k_t *sem, int timeout, void (*fct)(void));
/**
attach a timer to the semaphore so KRNL will signal the semaphore with
regular intervals. Can be used for cyclic real time run of a task.
@param[in] sem semaphore handle
@param[in] val interval in quant of KRNL ticks (0: disable cyclic timer,
1,2,3... cyclic quant)
@return -1: negative val, 0. ok
@remark only to be called after start of KRNL
*/
int k_set_sem_timer(struct k_t *sem, int val);
/**
Signal a semaphore. Can be called from an ISR when interrupt is disabled. No
task shift will occur - only queue manipulation.
@param[in] sem semaphore handle
@return 0: ok , -1: max value of semaphore reached
@remark only to be called after start of KRNL
*/
int ki_signal(struct k_t *sem);
/**
Signal a semaphore. Task shift will task place if a task is started by the
signal and has higher priority than you.
@param[in] sem semaphore handle
@return 0: ok , -1: max value of semaphore reached
@remark The ki_ indicates that interrups is NOT enabled when leaving
ki_signal
@remark only to be called after start of KRNL
*/
int k_signal(struct k_t *sem);
/**
Wait on a semaphore. Task shift will task place if you are blocked.
@param[in] sem semaphore handle
@param[in] timeout "<0" you will be started after timeout ticks, "=0" wait
forever "-1" you will not wait
@return 1: ok there was a signal hanging - so no suspension
@return 0: ok- you have been suspended
@return -1: timeout has occured, -2 no wait bq timeout was -1 and semaphore
was negative
@remark only to be called after start of KRNL
*/
int k_wait(struct k_t *sem, int timeout);
/**
Wait on a semaphore. Task shift will task place if you are blocked.
@param[in] sem semaphore handle
@param[in] timeout "<0" you will be started after timeout ticks, "=0" wait
forever "-1" you will not wait
@param[out] nrClip If not NULL you will get in return nr of clip on signals
on sem and clip counter will be set to 0
@return 1: ok there was a signal hanging - so no suspension
@return 0: ok- you have been suspended
@return -1: timeout has occured, -2 no wait bq timeout was -1 and semaphore
was negative
@remark only to be called after start of KRNL
*/
int k_wait2(struct k_t *sem, int timeout, int *nrClip);
/**
Returns how many signals has been lost on semaphore due to saturation
@param[in] sem semaphore handle
@return nr of signals lost
@remark only to be called after start of KRNL
*/
int k_sem_signals_lost(struct k_t *sem);
/**
Like k_wait with the exception interrupt is NOT enabled when leaving
@param[in] sem semaphore handle
@param[in] timeout "<0" you will be started after timeout ticks, "=0" wait
forever "-1" you will not wait
@return 0: ok , -1: could do wait bw blocking would have taken place
@remark The ki_ indicates that interrups is NOT enabled when leaving ki_wait
@remark only to be called after start of KRNL
@remark normally not to be used by users !!! BEWARE
*/
int ki_wait(struct k_t *sem, int timeout);
/**
returns value of semaphore
@param[in] sem semaphore handle
@return 1: ok not suspended, 0: ok you have been suspended
@return -1 no wait maybe bq no timeout was allowed
@remark only to be called after start of KRNL
@remark do not enable interrupt upon leaving
*/
int ki_semval(struct k_t *sem);
/**
returns value of semaphore
@param[in] sem semaphore handle
@return 1: ok not suspended, 0: ok you have been suspended
@return -1 no wait maybe bq no timeout was allowed
@remark only to be called after start of KRNL
*/
int k_semval(struct k_t *sem);
/**
* Clear semaphore if possible.
* Will set semaphore vallue 0 if possible (if no tasks is waiting)
* @param[in] sem pointer ref to semaphore
* @return semValue - if negative it indicates task are waiting and no clear
*
*/
int k_clear_sem(struct k_t *sem);
/**
returns nr of pending messages
@param[in] msgbuffer handle
xxx
*/
int ki_msg_count(struct k_msg_t *msgbuffer);
/**
returns nr of pending messages
@param[in] msgbuffer handle
@return 1: ok not suspended, 0: ok you have been suspended
@return -1 no wait maybe bq no timeout was allowed
@remark only to be called after start of KRNL
*/
int k_msg_count(struct k_msg_t *m);
/*********************************************************************
************************* DEBUG BREAKOUT FUNCTIONS *******************
**********************************************************************
*
* Breakout functions can be removed by commenting out define of
* KRNLBUG in krnl.h (located around line 216)
* All semaphore calls k_sem_clip, k_sem_signal, k_Sem_wait are all called
* AFTER decrement/incr of semaphore has taken place BUT before eventually
* taskshift.
*
* For message buffers/semaphores an internal semaphore is used for
synchronization
* so referring to the msgQ is by
* struct k_msg_t *msgSem; msgSem->sem->nr
*
*/
/**
a function for overloading on usersite which is called when a semaphore is
overflooding no occur - it's only reading out semaphore idendity Signal
operations has not taken place ! 1: means first semahore allocated by user, 2
the next etc Interrupt is disabled when called and must not be enabled
during.. so no print etc
@param[in] nr id of semaphore 1,2,3,...
@param[in] nrClip number of times clip has occured (may be reset by call
k_wait_lost)
*/
#ifdef KRNLBUG
void __attribute__((weak)) k_sem_clip(unsigned char nr, int nrClip);
#endif
/**
* called in a signal call val is sem val AFTER signal has taken place
* @param [out] nr number of semaphore. Semaphores are allocated by user buth
* also in message queues. So it may be diff to find the semaphore...
*
*/
#ifdef KRNLBUG
void __attribute__((weak)) k_sem_signal(unsigned char nr, int val);
#endif
/**
* called when wait called. val is sem value after countdown has taken place
* NB is the wait call willl not wait and there is no token at the semaphore
* val will be -1111
*/
#ifdef KRNLBUG
void __attribute__((weak)) k_sem_wait(unsigned char nr, int val);
#endif
/**
a function for overloading on usersite which is called when a msgQ is
overflooding no reset occur - it's only readind out smsgQ idendity 1: means
first msgQ allocated by user etc Interrupt is disabled when called and must
not be enabled during.. so no print etc
@param [out] nr : id of send Q 0,1,2,...
@param [out] nrClip: number of times clip has occured (may be reset by call
k_receive and lost parm not eq NULL)
*/
#ifdef KRNLBUG
void __attribute__((weak)) k_send_Q_clip(unsigned char nr, int nrClip);
#endif
struct k_msg_t *k_crt_send_Q(int nr_el, int el_size, void *pBuf);
/**
Put data (one element of el_size)in the ringbuffer if there are room for it.
Intended for ISR use
DONE BY COPY !
@param[in] pB Ref to message buffer
@param[in] el Reference to data to be put in buffer. Size if already given in
k_crt_send
@return 0: operation did succed, -1: no room in ringbuffer
@remark Interrupt will not enabled upon leaving, so ki_send is intended to be
used from an ISR
@remark only to be called before start of KRNL
*/
char ki_send(struct k_msg_t *pB, void *el);
/**
Put data (one element of el_size)in the ringbuffer if there are room for it.
DONE BY COPY !
@param[in] pB Ref to message buffer
@param [in] el Reference to data to be put in buffer. Size if already given
in k_crt_send
@return 0: operation did succed, -1: no room in ringbuffer
@remark only to be called after start of KRNL
@remark k_send does not block if no space in buffer. Instead -1 is returned
*/
char k_send(struct k_msg_t *pB, void *el);
/**
Receive data (one element of el_size)in the ringbuffer if there are data
DONE BY COPY !
@param[in] pB Ref to message buffer
@param [out] el Reference to where data shall be copied to at your site
@param[in] timeout Max time you want to wait on data, -1: never, 0: forever,
positive: nr of KRNL timer quants
@param[out] lost_msg nr of lost messages since last receive. will clip at
10000. If lost_msg ptr is NULL then overrun counter is not reset to 0.
@return 1: ok no suspension, 0: operation did succed, -1: no data in
ringbuffer
@remark only to be called after start of KRNL
*/
char k_receive(struct k_msg_t *pB, void *el, int timeout, int *lost_msg);
/**
Receive data (one element of el_size)in the ringbuffer if there are data
DONE BY COPY !
No blocking if no data
Interrupt will not be enabled after ki_receive and intr must be blocked prior
to call
@param[in] pB Ref to message buffer
@param[out] el Reference to where data shall be copied to at your site
@param[out] lost_msg nr of lost messages since last receive. will clip at
10000. If lost_msg ptr is NULL then overrun counter is not reset to 0
@return 1: data was rdy no suspension, 0: ok you have been suspended , -1:
no data in ringbuffer
@remark can be used from ISR
@remark only to be called after start of KRNL
*/
char ki_receive(struct k_msg_t *pB, void *el, int *lost_msg);
/**
* Empty sendQ
* @return given no of deleted messages
* @return -1 if its no a msg q
* @return -2 if krnl is not running
* @return 0 or positive gives no of messages deleted
*/
int ki_clear_msg_Q(struct k_msg_t *pB);
/**
* Empty sendQ
* See ki_clear_msg-Q for description
*/
int k_clear_msg_Q(struct k_msg_t *pB);
#ifdef READERWRITER
/**
initialise a reader-writers comples
*/
void k_rwInit(struct k_rwlock_t *lock);
/**
reader-writer Read enter
*/
int k_rwRdEnter(struct k_rwlock_t *lock, int timeout);
/**
reader-writer Write enter
*/
int k_rwWrEnter(struct k_rwlock_t *lock, int timeout);
/**
reader-writer Read leave
*/
int k_rwRdLeave(struct k_rwlock_t *lock);
/**
reader-writer Write leave
*/
int k_rwWrLeave(struct k_rwlock_t *lock);
#endif
/**
returns which timer is used
@return 0,1,2,3,4,5 ...
*/
int k_tmrInfo(void); // tm in milliseconds
/**
Initialise KRNL. First function to be called.
You have to give max number of tasks, semaphores and message queues you will
use
@param[in] nrTask ...
@param[in] nrSem ...
@param[in] nrMsg ...
*/
int k_init(int nrTask, int nrSem, int nrMsg);
/**
Starts krnl is possible
If there has been ciritcal errors between k_init and k_start (like no more
task descriptors) k_start will return a negative number indicatin how many
errors
If k_start starts you will not return from k_start
*/
int k_start(void); // tm in milliseconds
/**
stop KRNL
parm can be 1 or 10 can only run 1 og 10 msec tick speed
If krnl is not yet running you will return with a -1 as return value
If krnl is running interrupt will be disabled and k_stop ends in an infinite
loop
*/
int k_stop(); // tm in milliseconds
/**
Reset by disable interrupt plus activate watchdog (15 millisseconds) and just
wait...
**/
void k_reset();
/**
Initialise blink on pin 13
ON when dummy is running
Nov 2014 - fake do not use it bq it will not work
for emergency use :-)
*/
/**
returns nr of unbytes bytes on stak.
For chekking if stak is too big or to small...
@param[in] t Reference to task (by task handle) If null then yourself
@return: nr of unused bytes on stak (int)
@remark only to be called after start of KRNL
@remark no chk of if it is a valid task
*/
int k_stk_chk(struct k_t *t);
/**
Returns amount of unused stak
@param[in] t Ptr to taskdescriptor. If NULL it is yourself
@return: amount of unused stak(in bytes)
@remark: a watermark philosophy is used
@remark can be called from ISR . iif userapce you must disable intr
**/
int ki_unused_stak(struct k_t *t);
/**
Returns amount of unused stak
@param[in] t Ptr to taskdescriptor. If NULL it is yourself
@return: amount of unused stak(in bytes)
@remark: a watermark philosophy is used
**/
int k_unused_stak(struct k_t *t);
/**
Returns amount of unused stak for running task
@return: amount of unused stak(in bytes)
@remark: a watermark philosophy is used
@remark can be called from ISR . iif userapce you must disable intr
**/
int ki_my_unused_stak();
/**
* round robbin
* reinsert running task in activeQ.
* so running will be inserted after other tasks with same or higher priority
**/
void k_round_robbin(void);
/**
* release
* switch running to task in front of Active Q
* calls ki_task_shift (); enveloped by a DI and EI
* no round robbin
**/
void k_release(void);
/**
*/
void k_set_coop_multitask(unsigned char onn);
/**
* returns amount of free memory in your system
* (free size of heap) se docu in krnl.c
*/
int freeRam(void);
#ifdef KRNLBUG
/**
* Breakout function called from scheduler
* You can use to examine who is runnning and who is next
* NB NB should be fast code and remember interrupt is and must be disables
* pRun->nr Nr of running.
* dummy has nr == 0
* then task is numbered 1.. in acc with order of creation of tasks
* k_breakout is defined as weak function so you can write your own k_breakout
* The builtin k_breakout has no code and just a placeholder to be subst
* with your code.
* setting led8-12 on uno as task number
* PORTB = (1 << pRun->nr) | led13
**/
void __attribute__((weak)) k_breakout(void);
#endif
#ifdef __cplusplus
}
#endif
#endif // #ifndef KRNL
/*******************************************************
* *
* *
* | |/ /___| _ \| \ | | ___| | *
* | ' // _ \ |_) | \| |/ _ \ | *
* | . \ __/ _ <| |\ | __/ |___ *
* |_|\_\___|_| \_\_| \_|\___|_____| *
* *
* *
* you are watching krnl.c *
* *
* March 2015,2016,..,2018 *
* Author: jdn *
* Apr. 2023 *
*. *
(C) 2012,2013,2014
2017,2018,2019,2021,2022,2023
IF YOU ARE LUCKY LOOK HERE
https://github.com/jdn-aau/krnl
Jens Dalsgaard Nielsen <jdn@es.aau.dk>
http://es.aau.dk/staff/jdn
Section of Automation & Control
Aalborg University,
Denmark
"THE BEER-WARE LICENSE" (frit efter PHK)
<jdn@es.aau.dk> wrote this file. As long as you
retain this notice you can do whatever you want
with this stuff. If we meet some day, and you think
this stuff is worth it ...
you can buy me a beer in return :-)
or if you are real happy then ...
single malt will be well received :-)
Use it at your own risk - no warranty
nice info...
http://www.nongnu.org/avr-libc/user-manual/FAQ.html#faq_cplusplus
at 20090611
- k_eat_time now eats time in quants of krnl tick speed but not one quant
boundary
- added k_malloc and k_free
k_free dont free memory bq we do not want fragmentation
so DONT USE k_free
- k_malloc and k_free are weak functions so you can just add your own
versions
- watchdog is enabled (2sec and reset in krnl timer) in weak function
k_enable_wdt
************************************************************************/
#include "krnl.h"
#ifdef WDT_TIMER
#include <avr/wdt.h>
#endif
#include <stdlib.h>
//#define NULL (int)0
#include <avr/interrupt.h>
//TESTT #include <util/delay.h>
//TESTT #include <stdlib.h>
// CPU frequency
#if (F_CPU == 8000000)
#pragma message("krnl detected 8 MHz")
#endif
#if (KRNL_VRS != 20240525)
#error "KRNL VERSION NOT UPDATED in krnl.c "
#endif
/* which timer to use for krnl heartbeat
timer 0 ( 8 bit) is normally used by millis - avoid !
or modify TIMER0 in wiring.c
timer 1 (16 bit)
timer 2 ( 8 bit) DEFAULT for uno and mega
timer 3 (16 bit) 1280/1284P/2560 only (MEGA)
timer 4 (16 bit) 1280/2560 only (MEGA)
timer 5 (16 bit) 1280/2560 only (MEGA)
*/
//---------------------------------------------------------------------------
// TIME CONFIG REGISTERS
// TIME CONFIG REGISTERS
//---------------------------------------------------------------------------
#if (KRNLTMR == 0)
JDN SIGER NOGO IN SIMPLIFY VRS
#pragme err "tbf 0 "
// normally not goood bq of arduino sys timer is on timer 0so you wil get a
// compile error 8 bit timer !!!
//#define KRNLTMRVECTOR TIMER0_OVF_vect
/* we use setting from original timer0
#define TCNTx TCNT0
#define TCCRxA TCCR0A
#define TCCRxB TCCR0B
#define TCNTx TCNT0
#define OCRxA OCR0A
#define TIMSKx TIMSK0
#define TOIEx TOIE0
#define PRESCALE 0x07
#define COUNTMAX 0xff
#define DIVV 15.625
#define DIVV8 7.812
*/
//---------------------------------------------------------------------------
// TIMER 1
//---------------------------------------------------------------------------
#elif (KRNLTMR == 1)
empty
//---------------------------------------------------------------------------
// TIMER 2 - STANDARD - NB check for conflict with tone,pwm etc
//---------------------------------------------------------------------------
#elif (KRNLTMR == 2)
// 8 bit timer !!! STANDARD
// standard for krnl CHECK which pwm, tone etc is on this timer
#pragma warn "krnl timer on timer 2 - check PWM "
#define KRNLTMRVECTOR TIMER2_OVF_vect
#define TCNTx TCNT2
#define TCCRxA TCCR2A
#define TCCRxB TCCR2B
#define TCNTx TCNT2
#define OCRxA OCR2A
#define TIMSKx TIMSK2
#define TOIEx TOIE2
#define CNT_1MSEC 240
#define CNT_10MSEC 99
#define PRESCALE ((1 << CS22) | (1 << CS21) | (1 << CS20))
//---------------------------------------------------------------------------
// TIMER 3
//---------------------------------------------------------------------------
#elif (KRNLTMR == 3)
// 32u4
#define KRNLTMRVECTOR TIMER3_OVF_vect
#define TCNTx TCNT3
#define TCCRxA TCCR3A
#define TCCRxB TCCR3B
#define TCNTx TCNT3
#define OCRxA OCR3A
#define TIMSKx TIMSK3
#define TOIEx TOIE3
#define PRESCALE ((1 << CS02) | (1 << CS01) | (1 << CS00))
#define COUNTMAX 0xffff
#define CNT_1MSEC 65520
#define CNT_10MSEC 65381
//---------------------------------------------------------------------------
// TIMER 4
//---------------------------------------------------------------------------
#elif (KRNLTMR == 4)
#pragme err "tbf 4"
#elif (KRNLTMR == 5)
#pragme err "tbf 5"
#else
#pragma err "KRNL: no valid tmr selected"
#endif
//---------------------------------------------------------------------------
// KRNL VARIABLES
// KRNL VARIABLES
//---------------------------------------------------------------------------
struct k_t *task_pool, // array of descriptors for tasks
*sem_pool, // .. for semaphores
AQ, // Q head for active Q
*pmain_el, // procesdecriptor for main eq dummy
*pAQ, // head of activeQ (AQ)
*pRun, // who is running ?
*pSleepSem; // one semaphor for all to sleep at
struct k_msg_t *send_pool; // ptr to array for msg sem pool
int k_task, k_sem, k_msg; // From k_init
char nr_task = 0, nr_sem = 0, nr_send = 0; // counters for created elements
volatile char k_running = 0, k_err_cnt = 0;
volatile unsigned char tcntValue; // counters for timer system
//time
unsigned long k_millis_counter = 0;
unsigned int k_tick_size;
// coop multitasking
unsigned char k_coopFlag = 0;
int tmr_indx; // for travelling Qs in tmr isr
//---------------------------------------------------------------------------
// WDT
//---------------------------------------------------------------------------
#ifdef WDT_TIMER
#include <avr/wdt.h>
volatile char k_wdt_enabled = 1;
#endif
//---------------------------------------------------------------------------
// Queue OPerations (activeQ, semQ,...)
//---------------------------------------------------------------------------
//---QOPS--- double chained lists with qhead as a element
/* -<------<-------<--------<---------<------------<-
* | |
* \/ |
* QHEAD (next)-->first-elm (next)-->next-elm(next) --|
* ^ ^
* ------------(pred) -----------(pred) char
*
*/
// add element in end of Q ==just "before" q-head
void enQ(struct k_t *Q, struct k_t *el) {
el->next = Q;
el->pred = Q->pred;
Q->pred->next = el;
Q->pred = el;
}
// remove element from a queue
struct k_t *deQ(struct k_t *el) {
el->pred->next = el->next;
el->next->pred = el->pred;
return (el);
}
// insert element in Q acc to priority (1 ==highest prio)
void prio_enQ(struct k_t *Q, struct k_t *el) {
char prio = el->prio;
Q = Q->next; // bq first elm is Q head itself
while (Q->prio <= prio) // find place before next with lower prio
{
Q = Q->next;
}
el->next = Q; // insert before element referred by Q
el->pred = Q->pred;
Q->pred->next = el;
Q->pred = el;
}
/***** eat time ***/
/* real eat time so if you are blocked by higher priority task
the blockug time do not count
Can be use for simulate CPU usage
*/
void delayMicroseconds(unsigned int t);
void k_eat_msec(unsigned int eatTime) {
while (10 < eatTime) {
delayMicroseconds(10000);
eatTime -= 10;
}
delayMicroseconds(eatTime * 1000);
}
//---HW timer IRS--timer section------------------------
/*
The KRNL Timer is driven by timer
Install the Interrupt Service Routine (ISR) for Timer2 overflow.
This is normally done by writing the address of the ISR in the
interrupt vector table but conveniently done by using ISR()
Timer2 reload value, globally available
*/
/* from wiring.c
// the prescaler is set so that timer0 ticks every 64 clock cycles, and the
// the overflow handler is called every 256 ticks.
#define MICROSECONDS_PER_TIMER0_OVERFLOW (clockCyclesToMicroseconds(64 *
256))
// the whole number of milliseconds per timer0 overflow
#define MILLIS_INC (MICROSECONDS_PER_TIMER0_OVERFLOW / 1000)
// the fractional number of milliseconds per timer0 overflow. we shift right
// by three to fit these numbers into a byte. (for the clock speeds we care
// about - 8 and 16 MHz - this doesn't lose precision.)
#define FRACT_INC ((MICROSECONDS_PER_TIMER0_OVERFLOW % 1000) >> 3)
#define FRACT_MAX (1000 >> 3) which is
*/
int k_ticksize(void) {
return k_tick_size;
}
/**HERE**/
//----------------------------------------------------------------------------
// inspired from ...
// http://arduinomega.blogspot.dk/2011/05/timer2-and-overflow-interrupt-lets-get.html
// Inspiration from
// http://popdevelop.com/2010/04/mastering-timer-interrupts-on-the-arduino/
// Inspiration from "Multitasking on an AVR" by Richard Barry, March 2004
// and http://www.control.aau.dk/~jdn/kernels/krnl/
//----------------------------------------------------------------------------
// avrfreaks.net
// and my old kernel from last century
// and a lot other stuff
// basic concept from my own very old kernels dated back bef millenium
void __attribute__((naked, noinline)) ki_task_shift(void) {
PUSHREGS(); // push task regs on stak so we are rdy to task shift
K_CHG_STAK(); // find taskstak for task in front of activeQ
POPREGS(); // restore regs
RETI(); // and do a reti NB this also enables interrupt !!!
}
#ifdef BACKSTOPPER
void jumper() {
while (1) {
(*(pRun->pt))(); // call task
// you can just jump back to task, but your local vars in
// the task body will be wiped out
// or
// just hanging here
#ifdef STOP_IN_BACKSTOPPER
k_set_prio(ZOMBI_PRIO); // priority lower than dummy so you just stops
while (1)
; // just in case
#endif
}
}
#endif
struct k_t *k_crt_task(void (*pTask)(void), char prio, char *pStk,
int stkSize) {
struct k_t *pT;
int i;
char *s;
// sanity chek
if ((k_running) || ((prio <= 0) || (DMY_PRIO <= prio)) || (k_task <= nr_task)) {
goto badexit;
}
if (pStk == NULL) { // you didnt give me a stack
goto badexit;
}
pT = task_pool + nr_task; // lets take a task descriptor
pT->nr = nr_task;
nr_task++;
pT->cnt2 = 0; // no time out running on you for the time being
pT->cnt3 = 0; // no time out semaphore for you
pT->cnt1 = (int)(pStk); // ref to my stack
// ----- HW DEPENDENT START --------------
// ----- HW DEPENDENT START --------------
// paint stack with hash code to be used by k_unused_stak()
for (i = 0; i < stkSize; i++) {
pStk[i] = STAK_HASH;
}
s = pStk + stkSize - 1; // now we point on top of stak
*(s--) = 0x00; // 1 byte safety distance :-)
// an interrupt do only push PC on stack by HW - can be 2 or 3 bytes
// depending of 368/.../1280/2560
#ifdef BACKSTOPPER
pT->pt = pTask;
*(s--) = lo8(jumper); // so top now holds address of function
*(s--) = hi8(jumper); // which is code body for task
#else
*(s--) = lo8(pTask); // so top now holds address of function
*(s--) = hi8(pTask); // which is code body for task
#endif
// NB NB 2560 use 3 byte for call/ret addresses the rest only 2
#if defined(__AVR_ATmega2560__) || defined(__AVR_ATmega2561__)
*(s--) = EIND; // best guess : 3 byte addresses !!! or just 0
#endif
// r1 is the socalled zero value register
// see https://gcc.gnu.org/wiki/avr-gcc
// can tmp be non zero (multiplication etc)
*(s--) = 0x00; // r1
*(s--) = 0x00; // r0
*(s--) = 0x00; // sreg
// 1280 and 2560 need to save rampz reg just in case
#if defined(__AVR_ATmega2560__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega1284P__) || defined(__AVR_ATmega2561__)
*(s--) = RAMPZ; // best guess 0x3b
#endif
#if defined(__AVR_ATmega2560__) || defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2561__)
*(s--) = EIND; // best guess 0x3c
#endif
// rest of the resg on the stack
for (i = 0; i < 30; i++) // r2-r31 = 30 regs
{
*(s--) = 0x00;
}
pT->sp_lo = lo8(s); // now we just need to save stakptr
pT->sp_hi = hi8(s); // in thread descriptor
// ----- HW DEPENDENT ENDE --------------
// ----- HW DEPENDENT ENDE --------------
// ----- HW DEPENDENT ENDE --------------
pT->prio = prio;
pT->maxv = (int)prio; // maxv for holding org prio for inheritance
prio_enQ(pAQ, pT); // and put task in active Q
return (pT);
badexit:
k_err_cnt++;
return (NULL);
}
int freeRam(void) {
extern int __heap_start, *__brkval;
int x, v;
// NASTY
x = ((int)&v - (__brkval == 0 ? (int)&__heap_start : (int)__brkval)); // to remove warning
return x;
// hw specific :-/
// return ((int) &v - (__brkval == 0 ? (int) &__heap_start : (int) __brkval));
/* from
http://www.noah.org/wiki/Arduino_notes#debug_memory_problems_.28out_of_RAM.29
int freeRam () {
// __brkval is the address of the top of the heap if memory has been
allocated.
// If __brkval is zero then it means malloc has not used any memory yet, so
// we look at the address of __heap_start.
extern int __heap_start
extern int *__brkval; // address of the top of heap
int stack_top;
return (int)&stack_top - ((int)__brkval == 0 ? (int)&__heap_start :
(int)__brkval);
}
*/
}
int k_sleep(int time) {
int r;
if (time <= 0)
return -1;
r = k_wait(pSleepSem, time);
if (r == -1) // timeout ? yes :-)
return 0;
}
int ki_my_unused_stak() {
int i;
char *pstk;
pstk = (char *)(pRun->cnt1);
// look for stack paint
i = 0;
while (*pstk == STAK_HASH) {
pstk++;
i++;
}
return (i);
}
int ki_unused_stak(struct k_t *t) {
int i;
char *pstk;
if (t) // another task or yourself - NO CHK of validity !!!!!
{
pstk = (char *)(t->cnt1);
} else {
pstk = (char *)(pRun->cnt1);
}
// look for stack paint
i = 0;
while (*pstk == STAK_HASH) {
pstk++;
i++;
}
return (i);
}
int k_unused_stak(struct k_t *t) {
int i;
DI();
i = ki_unused_stak(t);
EI();
return (i);
}
int k_set_prio(char prio) {
int i;
if (!k_running) {
return (-2);
}
DI();
if ((prio <= 0) || (DMY_PRIO <= prio)) // not legal value my friend
{
EI();
return (-1);
}
i = pRun->prio;
pRun->prio = prio;
prio_enQ(pAQ, deQ(pRun));
ki_task_shift();
EI();
return (i);
}
int k_mut_ceil_set(struct k_t *sem, char prio) {
// NB NB assume semaphore is created prior to this call
// NO CHECK - no mercy !!!
// work only BEFORE k_start
if (k_running) {
return (-2); // bad bad
}
if ((prio <= 0) || (DMY_PRIO <= prio)) {
return (-1); // bad bad
}
sem->ceiling_prio = prio;
return 0; // OK
}
struct k_t *k_crt_sem(int init_val, int maxvalue) {
struct k_t *sem;
if (k_running) {
return (NULL);
}
if ((maxvalue < init_val)
|| (MAX_SEM_VAL < maxvalue)
|| (init_val < 0)
|| (maxvalue < 0)) {
goto badexit;
}
if (k_sem <= nr_sem) // no vacant in buf
{
goto badexit;
}
sem = sem_pool + nr_sem; // allocate it
sem->nr = nr_sem;
nr_sem++;
sem->cnt2 = 0; // no timer running
sem->next = sem->pred = sem; // point at myself == no one in Q
sem->prio = QHD_PRIO;
sem->cnt1 = init_val;
sem->maxv = maxvalue;
sem->clip = 0;
sem->ceiling_prio = -1; // to indicate it is not active
sem->saved_prio = -1;
return (sem);
badexit:
k_err_cnt++; // one more error so krnl will not start
return (NULL);
}
int k_set_sem_timer(struct k_t *sem, int val) {
// there is no k_stop_sem_timer fct just call with val== 0 for stopping timer
// fct
if (val < 0) {
return -1;
}
DI();
if (0 <= sem->cnt1) {
sem->cnt1 = 0; // reset
}
sem->cnt2 = sem->cnt3 = val; // if 0 then timer is not running -
EI();
return (0);
}
int ki_signal(struct k_t *sem) {
DI(); // just in case
if (sem->cnt1 < sem->maxv) {
sem->cnt1++; // Salute to Dijkstra
#ifdef KRNLBUG
k_sem_signal(sem->nr, sem->cnt1); // call to breakout functino
#endif
if (sem->cnt1 <= 0) {
sem->next->cnt2 = 0; // return code == ok in waiting tasks pocket(cnt2)
prio_enQ(pAQ, deQ(sem->next));
return (0); // a task was waiting and is now in AQ
} else {
return (1); // just delivered a signal - no task was waiting
}
} // CLIP :-(
else {
if (sem->clip < MAX_SEM_VAL + 1) {
sem->clip++;
}
// here we are on bad clip failure no signal takes place
// signal is lost !!!
#ifdef KRNLBUG
k_sem_clip(sem->nr, sem->clip);
#endif
return (-1);
}
}
int k_signal(struct k_t *sem) {
int res;
DI();
res = ki_signal(sem); // 1: ok no task to AQ, 0: ok task to AQ
if (res == 0) {
ki_task_shift(); // bq maybe started task has higher prio than me
}
EI();
return (res);
}
/* normally ki_wait should not be used by user */
int ki_wait(struct k_t *sem, int timeout) {
DI();
if (0 < sem->cnt1) {
sem->cnt1--; // Salute to Dijkstra
return (1); // ok: 1 bq we are not suspended
}
if (timeout < 0) // no luck, dont want to wait so bye bye
{
return (-1); // will not wait so bad luck
}
// from here we want to wait
pRun->cnt2 = timeout; // 0 == wait forever
if (timeout) { // so we can be removed if timeout occurs
pRun->cnt3 = (int)sem; // nasty keep ref to semaphore in task stomach
}
sem->cnt1--; // Salute to Diocjkstra
enQ(sem, deQ(pRun));
ki_task_shift();
// back again - have semaphore received signal or timeout ?
pRun->cnt3 = 0; // reset ref to timer semaphore
return ((char)(pRun->cnt2)); // 0: ok , -1: timeout
}
int k_wait(struct k_t *sem, int timeout) {
int retval;
DI();
retval = ki_wait(sem, timeout);
EI();
return retval; // 0: ok, -1: timeout
}
int k_wait2(struct k_t *sem, int timeout, int *nrClip) {
int retval;
DI();
retval = ki_wait(sem, timeout);
if (nrClip) {
*nrClip = sem->clip;
sem->clip = 0;
}
EI();
return retval; // 0: ok, -1: timeout
}
struct k_t *k_crt_mut(char ceiling_prio, int init_val, int maxvalue) {
struct k_t *mut;
if (k_running) {
return (NULL);
}
if (ceiling_prio < 0) {
k_err_cnt++;
return NULL;
}
mut = k_crt_sem(init_val, maxvalue);
if (mut == NULL) {
k_err_cnt++;
return NULL;
}
mut->ceiling_prio = ceiling_prio;
return mut;
}
int k_mut_ceil(struct k_t *sem, int timeout, void (*fct)(void)) {
int r;
r = k_mut_ceil_enter(sem, timeout);
if (r < 0) {
return r; // bad bad
}
(*fct)(); // call mutex function
k_mut_ceil_leave(sem);
return r;
}
int k_mut_ceil_enter(struct k_t *sem, int timeout) {
int retval;
DI();
if (sem->ceiling_prio < 0) {
EI();
return CEILINGFAILNOTCEIL;
}
if (pRun->prio < sem->ceiling_prio) { // I have higher priority than ceiling :-(
EI();
return CEILINGFAILPRIO;
}
// now we play imm ceiling protocol
sem->saved_prio = pRun->prio; // do im ceiling
pRun->prio =
sem->ceiling_prio; // dont need to reinsert in AQ bq ceil prio is higher
// or equal to mine and Im already in front of AQ
prio_enQ(pAQ, deQ(pRun)); // resinsert me in AQ acc to nwe(old) priority
retval = ki_wait(sem, timeout);
// coming back interrupt is still disabled !
// chk if we did get semaphore
if (retval < 0) { // NOPE we did not
pRun->prio = sem->saved_prio; // reset to my old priority
prio_enQ(pAQ, deQ(pRun)); // reinsert me in AQ acc to nwe(old) priority
ki_task_shift(); // bq maybe started task has higher prio than me
}
EI();
return retval; // 0(has waited),1(straight through) : ok, -1: timeout
}
int k_mut_ceil_leave(struct k_t *sem) {
int res;
DI();
res = ki_signal(sem); // 1: ok no task to AQ, 0: ok task to AQ
// coming back interrupt is still disabled !
pRun->prio = sem->saved_prio; // reset to my old priority
prio_enQ(pAQ, deQ(pRun)); // resinsert me in AQ acc to nwe(old) priority
ki_task_shift(); // bq maybe started task has higher prio than me
EI();
return (res);
}
int k_sem_signals_lost(struct k_t *sem) {
int x;
DI();
x = sem->clip;
sem->clip = 0;
EI();
return x;
}
int ki_semval(struct k_t *sem) {
DI(); // dont remove this - bq k_semval depends on it
return (sem->cnt1);
}
int k_semval(struct k_t *sem) {
int v;
v = ki_semval(sem);
EI();
return v;
}
int k_clear_sem(struct k_t *sem) {
DI();
if (0 <= sem->cnt1) {
sem->cnt1 = sem->clip = 0;
EI();
return 0;
}
else {
EI();
return -1;
}
}
int ki_msg_count(struct k_msg_t *m) {
DI(); // dont remove this - bq k_semval depends on it
return m->cnt;
}
int k_msg_count(struct k_msg_t *m) {
int v;
// not needed to DI - its in ki_msg_count ... DI ();
v = ki_msg_count(m);
EI();
return v;
}
struct k_msg_t *k_crt_send_Q(int nr_el, int el_size, void *pBuf) {
struct k_msg_t *pMsg;
if (k_running) {
return (NULL);
}
if (k_msg <= nr_send) {
goto errexit;
}
if (k_sem <= nr_sem) {
goto errexit;
}
pMsg = send_pool + nr_send;
pMsg->nr = nr_send; // I am element nr nr_send in msgQ pool
nr_send++;
pMsg->sem =
k_crt_sem(0, nr_el); // we are using a sem for sync part snd <-> rcv
if (pMsg->sem == NULL) {
goto errexit;
}
pMsg->pBuf = (char *)pBuf;
pMsg->r = pMsg->w = -1;
pMsg->el_size = el_size;
pMsg->nr_el = nr_el;
pMsg->lost_msg = 0;
pMsg->cnt = 0; // count nr elm in Q
return (pMsg);
errexit:
k_err_cnt++;
return (NULL);
}
int ki_clear_msg_Q(struct k_msg_t *pB) {
int ret;
if (k_running) {
return -2;
}
ret = pB->cnt;
if (0 < ret) { // messages pending s0
pB->lost_msg = 0;
pB->cnt = 0; // reset
pB->r = pB->w = -1;
// clear sem - can do it bq no one is waiting bq 0 < ret == pending
// messages
pB->sem->cnt1 = 0; // Serious NASTY
}
return ret;
}
int k_clear_msg_Q(struct k_msg_t *pB) {
int r;
DI();
r = ki_clear_msg_Q(pB);
EI();
return r;
}
char ki_send(struct k_msg_t *pB, void *el) {
int i;
char *pSrc, *pDst;
if (pB->nr_el <= pB->cnt) {
// nope - no room for a putting new msg in Q ?
if (pB->lost_msg < MAX_SEM_VAL) {
pB->lost_msg++;
}
#ifdef KRNLBUG
k_send_Q_clip(pB->nr, pB->lost_msg);
#endif
return (-1); // nope
} else {
pB->cnt++;
pSrc = (char *)el;
pB->w++;
if (pB->nr_el <= pB->w) // simple wrap around
{
pB->w = 0;
}
pDst = pB->pBuf + (pB->w * pB->el_size); // calculate where we shall put msg in ringbuf
for (i = 0; i < pB->el_size; i++) {
// copy to Q
*(pDst++) = *(pSrc++);
}
return (ki_signal(pB->sem)); // indicate a new msg is in Q
}
}
char k_send(struct k_msg_t *pB, void *el) {
char res;
DI();
res = ki_send(pB, el);
if (res == 0) // if new task in AQ == someone was waiting for msg
{ // if 1 then nobody was waiting so no neeed for task shift
ki_task_shift();
}
EI();
return (res);
}
char ki_receive(struct k_msg_t *pB, void *el, int *lost_msg) {
int i;
char r, *pSrc, *pDst;
// can be called from ISR bq no blocking
DI(); // just to be sure
if (0 <= (r = ki_wait(pB->sem, -1))) {
pDst = (char *)el;
pB->r++;
pB->cnt--; // got one
if (pB->nr_el <= pB->r) {
pB->r = 0;
}
pSrc = pB->pBuf + pB->r * pB->el_size;
for (i = 0; i < pB->el_size; i++) {
*(pDst++) = *(pSrc++);
}
if (lost_msg) {
*lost_msg = pB->lost_msg;
pB->lost_msg = 0;
}
return (r); // yes
}
return (-1); // nothing for you my friend
}
char k_receive(struct k_msg_t *pB, void *el, int timeout, int *lost_msg) {
int i;
char r, *pSrc, *pDst;
DI();
if (0 <= (r = ki_wait(pB->sem, timeout))) {
// yes we did get a msg :-)
// ki_wait bq then intr is not enabled when coming back
pDst = (char *)el;
pB->r++;
pB->cnt--; // got one
if (pB->nr_el <= pB->r) {
pB->r = 0;
}
pSrc = pB->pBuf + pB->r * pB->el_size;
for (i = 0; i < pB->el_size; i++) {
*(pDst++) = *(pSrc++);
}
if (lost_msg) {
*lost_msg = pB->lost_msg;
pB->lost_msg = 0;
}
EI();
return (r); // 1 if no suspension bq msg was already present, 0: ok if you
// have waited on msg
}
EI();
return (-1); // nothing for you my friend
}
#ifdef READERWRITER
// https://en.wikipedia.org/wiki/Readers%E2%80%93writers_problem
void k_rwInit(struct k_rwlock_t *lock) {
lock->nrReaders = 0;
lock->rdwrSem = k_crt_sem(1, 2);
lock->rdSem = k_crt_sem(1, 2);
lock->fifoSem = k_crt_sem(1, 2);
}
int k_rwRdEnter(struct k_rwlock_t *lock, int timeout) {
// timeout tbi later - if...
k_wait(lock->fifoSem, 0);
k_wait(lock->rdSem, 0);
lock->nrReaders++;
if (lock->nrReaders == 1)
k_wait(lock->rdwrSem, 0);
k_signal(lock->fifoSem);
k_signal(lock->rdSem);
}
int k_rwWrEnter(struct k_rwlock_t *lock, int timeout) {
k_wait(lock->fifoSem, 0);
k_wait(lock->rdwrSem, 0);
k_signal(lock->fifoSem);
}
int k_rwRdLeave(struct k_rwlock_t *lock) {
k_wait(lock->rdSem, 0);
lock->nrReaders--;
if (lock->nrReaders == 0) {
k_signal(lock->rdwrSem);
}
k_signal(lock->rdSem);
}
int k_rwWrLeave(struct k_rwlock_t *lock) {
k_signal(lock->rdwrSem);
}
#endif
void k_round_robbin(void) {
// reinsert running task in activeQ if round robbin is selected
DI();
prio_enQ(pAQ, deQ(pRun));
ki_task_shift();
EI();
}
void k_release(void) {
// let next run
DI();
ki_task_shift();
EI();
}
/* NASTY void from vrs 2001 it is main itself can be changed back
*/
/*
void
dummy_task (void)
{
while (1) {
k_round_robbin ();
}
}
*/
// char dmy_stk[DMY_STK_SZ]; // dmy duty is nwo maintained by org main
int k_init(int nrTask, int nrSem, int nrMsg) {
if (k_running) {
return (-666);
}
k_task = nrTask + 1; // +1 due to dummy
k_sem = nrSem + nrMsg + 1; // due to that every msgQ has a builtin semaphore
k_msg = nrMsg + 1; // to align so first user msgQ has index 1
nr_send++; // to align so we waste one but ... better equal access
task_pool = (struct k_t *)malloc(k_task * sizeof(struct k_t));
sem_pool = (struct k_t *)malloc(k_sem * sizeof(struct k_t));
send_pool = (struct k_msg_t *)malloc(k_msg * sizeof(struct k_msg_t));
// we dont accept any errors
if ((task_pool == NULL) || (sem_pool == NULL) || (send_pool == NULL)) {
k_err_cnt++;
goto leave;
}
// init AQ as empty double chained list
pAQ = &AQ;
pAQ->next = pAQ->pred = pAQ;
pAQ->prio = QHD_PRIO;
// crt dummy
// pDmy = k_crt_task (dummy_task, DMY_PRIO, DMY_STK_SZ);
pmain_el = task_pool;
pmain_el->nr = 0;
pmain_el->cnt2 = pmain_el->cnt3 = 0;
nr_task++;
pmain_el->prio = DMY_PRIO; // main is dummy
prio_enQ(pAQ, pmain_el);
pSleepSem = k_crt_sem(0, 10);
leave:
return k_err_cnt;
}
int k_start() {
/*
https://microcontrollerslab.com/arduino-timer-interrupts-tutorial/
https://wolles-elektronikkiste.de/en/timer-and-pwm-part-1-8-bit-timer0-2
FOR TIMER 2 !!! not TIMER0(8 bit) AND NOT TIMER 1(16bit) !!
TCCRxB
48,88,168,328, 1280,2560
timer 0 and 2 has same prescaler config:
8 bit:
0 0 0 No clock source (Timer/Counter stopped).
0 0 1 clk T2S /(No prescaling)
0 1 0 clk T2S /8 (From prescaler) 16M/2 = 2000000 intr/sec at 1 downcount
0 1 1 clk T2S /32 (From prescaler) 500000 intr/sec ...
1 0 0 clk T2S /64 (From prescaler) 250000
1 0 1 clk T2S /128 (From prescaler) 125000
1 1 0 clk T 2 S /256 (From prescaler) 62500
1 1 1 clk T 2 S /1024 (From prescaler) 16M/1024=15625 eq 15.625 count down for 1
millisec so 255 counts ~= 80.32 milli sec timer
timer 1(328+megas), 3,4,5(megas only)
1280, 2560,2561 has same prescaler config :
FOR 16 bits !
prescaler in cs2 cs1 cs0
0 0 0 none
0 0 1 /1 == none
0 1 0 /8 2000000 intr/sec
0 1 1 /64 250000 intr/sec
1 0 0 /256 62500 intr/sec
1 0 1 /1024 15625 intr/sec
16MHz Arduino -> 16000000/1024 = 15625 intr/second at one count
16MHz Arduino -> 16000000/256 = 62500 ticks/second
-------------------------/64 = 250000 ticks/second !
NB 16 bit counter so values >= 65535 is not working
*************************************************************************************
*/
// will not start if errors during initialization
if (k_err_cnt) {
return -k_err_cnt;
}
k_tick_size = K_TICK;
DI(); // silencio
// outdated ? JDN NASTY
#if defined(__AVR_ATmega32U4__)
// 32u4 have no intern/extern clock source register
#else
// should be default ASSR &= ~(1 << AS2); // Select clock source: internal
// I/O clock 32u4 does not have this facility
#endif
// TIMER2 I ASSUME !
//set PRESCALE bits cs22 cs21 cs20 to 0x05 fo clock div by 1024
//16MHz/1024 = 15625 kHz interrupt (or
// its equal to 0.064 msec pr count
// for 1 msec tick we shall count to 15(0.96msec) or 16(1.024msec)
// we prefer same freq all time instead of a leap second strategy
//https://wolles-elektronikkiste.de/en/timer-and-pwm-part-1-8-bit-timer0-2
// (1/16000000)*1024*16 = 1,024msec
// (1/16000000)*1024*157 = 10,048 msec
DI();
TCCRxA = 0x00; // Wave Form Generation Mode 0: Normal Mode; OC2A disconnected
TCCRxB = PRESCALE; //(1<< CS22) | (1 << CS21)| (1 << CS20);//0x05; // CS2 CS1 CS0 set so prescaler = 1024
TIMSKx = (1 << TOIEx); // interrupt when TCNT2 is overflowed
TCNTx = CNT_1MSEC;
// let us start the show
TIMSKx |= (1 << TOIEx); // enable interrupt
pRun = pmain_el; // just for ki_task_shift
k_running = 1;
ki_task_shift(); // bye bye from here
EI();
// this while loop bq main are dummy
while (1) {
}
return 0;
}
int k_stop() {
/*
main is dummy task so it gives no meaning to stop krnl this way
The best and dirty thing is
her DI(); while (1);
*/
// DANGEROUS - handle with care - no isr timer control etc etc
// I WILL NEVER USE IT
DI(); // silencio
if (!k_running) {
EI();
return -1;
}
while (1)
; // we stuck here with intr disabled !!!
}
void k_set_coop_multitask(unsigned char onn) {
k_coopFlag = onn;
}
unsigned long ki_millis(void) {
unsigned long l;
DI(); // just to be sure
l = k_millis_counter;
return l;
}
unsigned long k_millis(void) {
unsigned long l;
DI();
l = k_millis_counter;
EI();
return l;
}
int k_tmrInfo(void) {
return (KRNLTMR);
}
struct k_t *pE; // used only in ISR as "temporary var"
ISR(KRNLTMRVECTOR, ISR_NAKED) // naked so we have to supply with prolog and
// epilog (push pop stack of regs)
{
PUSHREGS(); // no local vars ! I think
if (!k_running) {
goto exitt;
}
TCNT2 = CNT_1MSEC; // Reload the timer 1 msec
#ifdef WDT_TIMER
if (k_wdt_enabled)
wdt_reset();
#endif
k_millis_counter += k_tick_size; // my own millis counter
// the following may look crazy: to go throuh all semaphores and tasks
// but you may have 3-4 tasks and 3-6 semaphores in your code
// so - seems to be efficient :-)
// so - it's a good idea not to init krnl with more items
// (tasks/Sem/msg descriptors than needed)
pE = sem_pool; // Semaphore timer - check timers on semaphores
for (tmr_indx = 0; tmr_indx < nr_sem; tmr_indx++) {
if (0 < pE->cnt2) // timer on semaphore ?
{
pE->cnt2--; // yep decrement it
if (pE->cnt2 <= 0) // timeout ?
{
pE->cnt2 =
pE->cnt3; // preset again - if cnt3 == 0 and >= 0 the rep timer
ki_signal(pE); // issue a signal to the semaphore
}
}
pE++;
}
pE = task_pool; // Chk timers on tasks - they may be one shoot waiting
for (tmr_indx = 0; tmr_indx < nr_task; tmr_indx++) {
if (0 < pE->cnt2) // timer active on task ?
{
pE->cnt2--; // yep so let us do one down count
if (pE->cnt2 <= 0) // timeout ? ( == 0 )
{
((struct k_t *)(pE->cnt3))
->cnt1++; // leaving sem so adjust semcount on sem
prio_enQ(pAQ, deQ(pE)); // and rip task of semQ and insert in activeQ
pE->cnt2 =
-1; // indicate timeout in this semQ for the task that is restartet
}
}
pE++;
}
if (!k_coopFlag) {
prio_enQ(pAQ, deQ(pRun)); // round robbin
K_CHG_STAK(); // let first in AQ run
}
exitt:
POPREGS();
RETI();
}
#ifdef KRNLBUG
// defined as weak so compiler will take yours instead of mine
void __attribute__((weak)) k_breakout(void) {}
void __attribute__((weak)) k_sem_clip(unsigned char nr, int nrClip) {}
void __attribute__((weak)) k_sem_signal(unsigned char nr, int semVal) {}
void __attribute__((weak)) k_sem_wait(unsigned char nr, int semVal) {}
void __attribute__((weak)) k_send_Q_clip(unsigned char nr, int nrClip) {}
#endif
#ifdef DYNMEMORY
void *__attribute__((weak)) k_malloc(int k) {
void *m;
DI();
m = malloc(k);
EI();
return m;
}
void __attribute__((weak)) k_free(void *m) {
// we dont free memory
}
#endif
void __attribute__((weak)) k_wdt_enable(int i) {
DI();
wdt_enable(i);
k_wdt_enabled = 1;
EI();
}
void __attribute__((weak)) k_wdt_disable(void) {
DI();
k_wdt_enabled = 0;
wdt_disable();
EI();
}
/* EOF - JDN */
/*
#ifdef __cplusplus
}
#endif
*/
And some examples
Src folder list: here
And the rest
krnl howto for Arduino
The proper place to put them in your Arduino environment:
sketchbook/libraries/krnl/.
sketchbook/libraries/krnl/krnl.cpp
Please note the cpp naming and that directory in libraries has same name as the cpp file
For using it in your code start with sketch>Import Libray>Contributed and select krnl
Then it will add a standard include <krnl.h> in your sketch and you are rdy to go
make directory krnl in …/sketchbook/libraries
copy krnl.h to ../sketchbook/libraries/krnl/krnl.h
copy krnl.c to ../sketchbook/libraries/krnl/krnl.cpp
Start Arduino SW
select Sketch -> Import Library -> krnl
It will add
If you want to have the examples I have provided (not all are bug free I think) then you have to …
make directory ../sketchbook/krnl
copy the examples in this directory
You can now find them in File->Sketchbook->krnl->“examples…”
For getting a copy for yourself:
might not be uptodate
git clone git://github.com/jdn-aau/krnl
/Jens
Performance
A task shift takes approx 21 usec. See perf.html for the test program
happy hacking
Jens
THE BEER-WARE LICENSE (Revision v xxx)
I did write this file.
As long as you retain this notice you can do whatever you want with this stuff on these pages.
If we meet some day, and you think this stuff is worth it, you can buy me a beer in return :-)
(C) JensD
credit for license this goes to the creator
I did write this file.
As long as you retain this notice you can do whatever you want with this stuff on these pages.
If we meet some day, and you think this stuff is worth it, you can buy me a beer in return :-)
(C) JensD
credit for license this goes to the creator