You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/* See the end of this file for copyright, license, and warranty information. */
|
|
|
|
#include <arch-generic/do_switch.h>
|
|
#include <arch-generic/sched.h>
|
|
#include <arch/hardware.h>
|
|
#include <arch/interrupt.h>
|
|
#include <arch/linker.h>
|
|
|
|
#include <ardix/atomic.h>
|
|
#include <ardix/kevent.h>
|
|
#include <ardix/malloc.h>
|
|
#include <ardix/sched.h>
|
|
#include <ardix/serial.h>
|
|
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
volatile unsigned long int tick = 0;
|
|
|
|
static unsigned int systick_reload;
|
|
static unsigned int tick_freq;
|
|
|
|
void handle_sys_tick(void)
|
|
{
|
|
tick++;
|
|
|
|
/*
|
|
* fire a PendSV exception and do the actual context switching there
|
|
* because the docs say you're supposed to do it that way
|
|
*/
|
|
if (!is_atomic())
|
|
SCB->ICSR |= SCB_ICSR_PENDSVSET_Msk;
|
|
}
|
|
|
|
int arch_sched_init(unsigned int freq)
|
|
{
|
|
tick_freq = freq;
|
|
systick_reload = SystemCoreClock / freq;
|
|
if ((systick_reload & SysTick_LOAD_RELOAD_Msk) != systick_reload)
|
|
return 1;
|
|
|
|
/* no subgrouping */
|
|
NVIC_SetPriorityGrouping(0b011);
|
|
|
|
SysTick_Config(systick_reload);
|
|
|
|
/* give PendSV the lowest priority so it doesn't interrupt irq handlers */
|
|
__set_BASEPRI(0);
|
|
NVIC_SetPriority(PendSV_IRQn, 0xf);
|
|
|
|
return 0;
|
|
}
|
|
|
|
void task_init(struct task *task, int (*entry)(void))
|
|
{
|
|
task->bottom = task->stack + CONFIG_STACK_SIZE;
|
|
/* TODO: Use separate stacks for kernel and program */
|
|
struct hw_context *hw_context = task->bottom - sizeof(*hw_context);
|
|
struct exc_context *exc_context = (void *)hw_context - sizeof(*exc_context);
|
|
|
|
memset(hw_context, 0, task->bottom - (void *)hw_context);
|
|
/*
|
|
* The return value of entry(), which is the exit code, will be stored
|
|
* in r0 as per the AAPCS. Conveniently, this happens to be the same
|
|
* register that is also used for passing the first argument to a
|
|
* function, so by setting the initial link register to exit() we
|
|
* effectively inject a call to that function after the task's main
|
|
* routine returns.
|
|
*/
|
|
hw_context->lr = exit;
|
|
hw_context->pc = entry;
|
|
hw_context->psr = 0x01000000; /* Thumb = 1, unprivileged */
|
|
|
|
exc_context->sp = hw_context;
|
|
exc_context->lr = (void *)0xfffffff9; /* leave exception, use MSP */
|
|
|
|
memset(&task->tcb, 0, sizeof(task->tcb));
|
|
task->tcb.context.sp = exc_context;
|
|
task->tcb.context.pc = _leave;
|
|
task->tcb.exc_context = exc_context;
|
|
}
|
|
|
|
__naked int _idle(void)
|
|
{
|
|
/* TODO: put the CPU to sleep */
|
|
while (1);
|
|
}
|
|
|
|
unsigned long int ms_to_ticks(unsigned long int ms)
|
|
{
|
|
return ( ms * (unsigned long int)tick_freq ) / 1000lu /* 1 s = 1000 ms */;
|
|
}
|
|
|
|
/*
|
|
* This file is part of Ardix.
|
|
* Copyright (c) 2020, 2021 Felix Kopp <owo@fef.moe>.
|
|
*
|
|
* Ardix is non-violent software: you may only use, redistribute,
|
|
* and/or modify it under the terms of the CNPLv6+ as found in
|
|
* the LICENSE file in the source code root directory or at
|
|
* <https://git.pixie.town/thufie/CNPL>.
|
|
*
|
|
* Ardix comes with ABSOLUTELY NO WARRANTY, to the extent
|
|
* permitted by applicable law. See the CNPLv6+ for details.
|
|
*/
|