+++ /dev/null
-/*
- * Copyright © 2009 Keith Packard <keithp@keithp.com>
- *
- * 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; 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
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- */
-
-#include "ao.h"
-
-#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_index;
-__xdata struct ao_task *__data ao_cur_task;
-
-void
-ao_add_task(__xdata struct ao_task * task, void (*start)(void), __code char *name) __reentrant
-{
- uint8_t __xdata *stack;
- uint8_t task_id;
- uint8_t t;
- if (ao_num_tasks == AO_NUM_TASKS)
- ao_panic(AO_PANIC_NO_TASK);
- for (task_id = 1; task_id != 0; task_id++) {
- for (t = 0; t < ao_num_tasks; t++)
- if (ao_tasks[t]->task_id == task_id)
- break;
- if (t == ao_num_tasks)
- break;
- }
- ao_tasks[ao_num_tasks++] = task;
- task->task_id = task_id;
- task->name = name;
- /*
- * Construct a stack frame so that it will 'return'
- * to the start of the task
- */
- stack = task->stack;
-
- *stack++ = ((uint16_t) start); /* 0 */
- *stack++ = ((uint16_t) start) >> 8; /* 1 */
-
- /* and the stuff saved by ao_switch */
- *stack++ = 0; /* 2 acc */
- *stack++ = 0x80; /* 3 IE */
-
- /* 4 DPL
- * 5 DPH
- * 6 B
- * 7 R2
- * 8 R3
- * 9 R4
- * 10 R5
- * 11 R6
- * 12 R7
- * 13 R0
- * 14 R1
- * 15 PSW
- * 16 BP
- */
- for (t = 0; t < 13; t++)
- *stack++ = 0;
-
- task->stack_count = 17;
- task->wchan = NULL;
-}
-
-/* Task switching function. This must not use any stack variables */
-void
-ao_yield(void) __naked
-{
-
- /* 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 enable interrupts. */
- push _IEN0
- setb _EA
- push DPL
- push DPH
- push b
- push ar2
- push ar3
- push ar4
- push ar5
- push ar6
- push ar7
- push ar0
- push ar1
- push PSW
- _endasm;
- PSW = 0;
- _asm
- push _bp
- _endasm;
-
- if (ao_cur_task_index == AO_NO_TASK_INDEX)
- ao_cur_task_index = ao_num_tasks-1;
- else
- {
- uint8_t stack_len;
- __data uint8_t *stack_ptr;
- __xdata uint8_t *save_ptr;
- /* Save the current stack */
- 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;
- do
- *save_ptr++ = *stack_ptr++;
- while (--stack_len);
- }
-
- /* Empty the stack; might as well let interrupts have the whole thing */
- 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
- */
- {
- __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;
- }
-
- /* Check if the alarm is set for a time which has passed */
- if (ao_cur_task->alarm &&
- (int16_t) (ao_time() - ao_cur_task->alarm) >= 0) {
- 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;
- }
- }
-
- {
- 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
- pop PSW
- pop ar1
- pop ar0
- pop ar7
- pop ar6
- pop ar5
- pop ar4
- pop ar3
- pop ar2
- pop b
- pop DPH
- pop DPL
- /* The next byte of the stack is the IE register. Only the global
- enable bit forms part of the task context. Pop off the IE then set
- the global enable bit to match that of the stored IE register. */
- pop ACC
- JB ACC.7,0098$
- CLR _EA
- LJMP 0099$
- 0098$:
- SETB _EA
- 0099$:
- /* Finally pop off the ACC, which was the first register saved. */
- pop ACC
- ret
- _endasm;
-}
-
-uint8_t
-ao_sleep(__xdata void *wchan)
-{
- __critical {
- ao_cur_task->wchan = wchan;
- }
- ao_yield();
- ao_cur_task->alarm = 0;
- if (ao_cur_task->wchan) {
- ao_cur_task->wchan = NULL;
- return 1;
- }
- return 0;
-}
-
-void
-ao_wakeup(__xdata void *wchan)
-{
- uint8_t i;
-
- for (i = 0; i < ao_num_tasks; i++)
- if (ao_tasks[i]->wchan == wchan)
- ao_tasks[i]->wchan = NULL;
-}
-
-void
-ao_alarm(uint16_t delay)
-{
- /* Make sure we sleep *at least* delay ticks, which means adding
- * one to account for the fact that we may be close to the next tick
- */
- if (!(ao_cur_task->alarm = ao_time() + delay + 1))
- ao_cur_task->alarm = 1;
-}
-
-void
-ao_exit(void) __critical
-{
- uint8_t i;
- ao_num_tasks--;
- for (i = ao_cur_task_index; i < ao_num_tasks; i++)
- ao_tasks[i] = ao_tasks[i+1];
- ao_cur_task_index = AO_NO_TASK_INDEX;
- ao_yield();
- /* we'll never get back here */
-}
-
-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_index = AO_NO_TASK_INDEX;
- ao_cur_task = NULL;
- ao_yield();
-}
projects / fw / altos / blobdiff