*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
+ * the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
#include "ao.h"
-#define AO_NO_TASK 0xff
+#define AO_NO_TASK_INDEX 0xff
__xdata struct ao_task * __xdata ao_tasks[AO_NUM_TASKS];
__data uint8_t ao_num_tasks;
-__data uint8_t ao_cur_task_id;
+__data uint8_t ao_cur_task_index;
__xdata struct ao_task *__data ao_cur_task;
void
-ao_add_task(__xdata struct ao_task * task, void (*start)(void))
+ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *name) __reentrant
{
uint8_t __xdata *stack;
if (ao_num_tasks == AO_NUM_TASKS)
- ao_panic(AO_ERROR_NO_TASK);
+ ao_panic(AO_PANIC_NO_TASK);
ao_tasks[ao_num_tasks++] = task;
+ task->task_id = ao_num_tasks;
+ task->name = name;
/*
* Construct a stack frame so that it will 'return'
* to the start of the task
void
ao_yield(void) _naked
{
- static uint8_t __data stack_len;
- static __data uint8_t * __data stack_ptr;
- static __xdata uint8_t * __data save_ptr;
/* Save current context */
_asm
/* Push ACC first, as when restoring the context it must be restored
* last (it is used to set the IE register). */
push ACC
- /* Store the IE register then disable interrupts. */
+ /* Store the IE register then enable interrupts. */
push _IEN0
- clr _EA
+ setb _EA
push DPL
push DPH
push b
push _bp
_endasm;
- if (ao_cur_task_id != AO_NO_TASK)
+ if (ao_cur_task_index != AO_NO_TASK_INDEX)
{
+ uint8_t stack_len;
+ __data uint8_t *stack_ptr;
+ __xdata uint8_t *save_ptr;
/* Save the current stack */
- stack_len = SP - AO_STACK_START;
+ stack_len = SP - (AO_STACK_START - 1);
ao_cur_task->stack_count = stack_len;
stack_ptr = (uint8_t __data *) AO_STACK_START;
save_ptr = (uint8_t __xdata *) ao_cur_task->stack;
- while (stack_len--)
+ do
*save_ptr++ = *stack_ptr++;
+ while (--stack_len);
}
/* Empty the stack; might as well let interrupts have the whole thing */
- SP = AO_STACK_START;
+ SP = AO_STACK_START - 1;
/* Find a task to run. If there isn't any runnable task,
* this loop will run forever, which is just fine
*/
- for (;;) {
- ++ao_cur_task_id;
- if (ao_cur_task_id == ao_num_tasks)
- ao_cur_task_id = 0;
- ao_cur_task = ao_tasks[ao_cur_task_id];
- if (ao_cur_task->wchan == NULL)
- break;
+ {
+ __pdata uint8_t ao_next_task_index = ao_cur_task_index;
+ for (;;) {
+ ++ao_next_task_index;
+ if (ao_next_task_index == ao_num_tasks)
+ ao_next_task_index = 0;
+
+ ao_cur_task = ao_tasks[ao_next_task_index];
+ if (ao_cur_task->wchan == NULL) {
+ ao_cur_task_index = ao_next_task_index;
+ break;
+ }
+
+ /* Enter lower power mode when there isn't anything to do */
+ if (ao_next_task_index == ao_cur_task_index)
+ PCON = PCON_IDLE;
+ }
}
- /* Restore the old stack */
- stack_len = ao_cur_task->stack_count;
- stack_ptr = (uint8_t __data *) AO_STACK_START;
- save_ptr = (uint8_t __xdata *) ao_cur_task->stack;
- while (stack_len--)
- *stack_ptr++ = *save_ptr++;
- SP = (uint8_t) (stack_ptr - 1);
+ {
+ uint8_t stack_len;
+ __data uint8_t *stack_ptr;
+ __xdata uint8_t *save_ptr;
+
+ /* Restore the old stack */
+ stack_len = ao_cur_task->stack_count;
+ SP = AO_STACK_START - 1 + stack_len;
+
+ stack_ptr = (uint8_t __data *) AO_STACK_START;
+ save_ptr = (uint8_t __xdata *) ao_cur_task->stack;
+ do
+ *stack_ptr++ = *save_ptr++;
+ while (--stack_len);
+ }
_asm
pop _bp
_endasm;
}
-int
+void
ao_sleep(__xdata void *wchan)
{
- ao_cur_task->wchan = wchan;
+ __critical {
+ ao_cur_task->wchan = wchan;
+ }
ao_yield();
}
-int
+void
ao_wakeup(__xdata void *wchan)
{
uint8_t i;
ao_tasks[i]->wchan = NULL;
}
+void
+ao_task_info(void)
+{
+ uint8_t i;
+ uint8_t pc_loc;
+ __xdata struct ao_task *task;
+
+ for (i = 0; i < ao_num_tasks; i++) {
+ task = ao_tasks[i];
+ pc_loc = task->stack_count - 17;
+ printf("%12s: wchan %04x pc %04x\n",
+ task->name,
+ (int16_t) task->wchan,
+ (task->stack[pc_loc]) | (task->stack[pc_loc+1] << 8));
+ }
+}
+
void
ao_start_scheduler(void)
{
- ao_cur_task_id = AO_NO_TASK;
+ ao_cur_task_index = AO_NO_TASK_INDEX;
ao_cur_task = NULL;
ao_yield();
}