From 3d3f849c9af9028f667cef4afedc0798d39a9efc Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Sun, 12 Apr 2009 21:33:46 -0700 Subject: [PATCH] SP points at last pushed byte --- ao_task.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/ao_task.c b/ao_task.c index 4f7387e3..a0c39ec9 100644 --- a/ao_task.c +++ b/ao_task.c @@ -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 -- 2.30.2