diff options
| author | Keith Packard <keithp@keithp.com> | 2009-04-12 21:33:46 -0700 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2009-04-12 21:33:46 -0700 |
| commit | 3d3f849c9af9028f667cef4afedc0798d39a9efc (patch) | |
| tree | 181af2302ef11f3a302e7cb8a656d473897df132 | |
| parent | f72c4cbc8fd9412dd1cce0fc446e7bbd2edc2d34 (diff) | |
SP points at last pushed byte
| -rw-r--r-- | ao_task.c | 11 |
1 files changed, 6 insertions, 5 deletions
@@ -74,9 +74,9 @@ ao_yield(void) _naked /* 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 @@ -98,7 +98,7 @@ ao_yield(void) _naked if (ao_cur_task_id != AO_NO_TASK) { /* 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; @@ -107,7 +107,7 @@ ao_yield(void) _naked } /* 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 @@ -123,11 +123,12 @@ ao_yield(void) _naked /* 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; while (stack_len--) *stack_ptr++ = *save_ptr++; - SP = (uint8_t) (stack_ptr - 1); _asm pop _bp |