diff options
Diffstat (limited to 'src/ao_task.c')
-rw-r--r-- | src/ao_task.c | 275 |
1 files changed, 0 insertions, 275 deletions
diff --git a/src/ao_task.c b/src/ao_task.c deleted file mode 100644 index f5850fa4..00000000 --- a/src/ao_task.c +++ /dev/null @@ -1,275 +0,0 @@ -/* - * 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(); -} |