diff options
| author | Keith Packard <keithp@keithp.com> | 2013-04-30 19:04:26 -0700 |
|---|---|---|
| committer | Keith Packard <keithp@keithp.com> | 2013-05-07 20:08:00 -0700 |
| commit | 1e9b405e939136d25d937334d1f14f06c7d6127b (patch) | |
| tree | 41231eaa27550b5a5f0fd43022c5a4ef3c37cb15 | |
| parent | ac72d1c298fc553808a8e04a65482d4990f177d7 (diff) | |
altos: Use separate exception stack on STM32L
This reserves 512 bytes of memory for a stack, then makes sure that
exceptions continue to use that stack while processes use the per-task
stack.
Signed-off-by: Keith Packard <keithp@keithp.com>
| -rw-r--r-- | src/core/ao_task.c | 3 | ||||
| -rw-r--r-- | src/stm/altos.ld | 6 | ||||
| -rw-r--r-- | src/stm/ao_arch_funcs.h | 13 |
3 files changed, 20 insertions, 2 deletions
diff --git a/src/core/ao_task.c b/src/core/ao_task.c index 9cb074b5..c24c9929 100644 --- a/src/core/ao_task.c +++ b/src/core/ao_task.c @@ -536,5 +536,8 @@ ao_start_scheduler(void) ao_cur_task_index = AO_NO_TASK_INDEX; #endif ao_cur_task = NULL; +#if HAS_ARCH_START_SCHEDULER + ao_arch_start_scheduler(); +#endif ao_yield(); } diff --git a/src/stm/altos.ld b/src/stm/altos.ld index f78a45d6..d218e992 100644 --- a/src/stm/altos.ld +++ b/src/stm/altos.ld @@ -17,7 +17,8 @@ MEMORY { rom (rx) : ORIGIN = 0x08000000, LENGTH = 128K - ram (!w) : ORIGIN = 0x20000000, LENGTH = 16K + ram (!w) : ORIGIN = 0x20000000, LENGTH = 15872 + stack (!w) : ORIGIN = 0x20003e00, LENGTH = 512 } INCLUDE registers.ld @@ -63,8 +64,9 @@ SECTIONS { __bss_end__ = .; } >ram - PROVIDE(__stack__ = ORIGIN(ram) + LENGTH(ram)); PROVIDE(end = .); + + PROVIDE(__stack__ = ORIGIN(stack) + LENGTH(stack)); } ENTRY(start); diff --git a/src/stm/ao_arch_funcs.h b/src/stm/ao_arch_funcs.h index d1779307..f3d68202 100644 --- a/src/stm/ao_arch_funcs.h +++ b/src/stm/ao_arch_funcs.h @@ -317,6 +317,19 @@ static inline void ao_arch_restore_stack(void) { asm("bx lr"); } +#define HAS_ARCH_START_SCHEDULER 1 + +static inline void ao_arch_start_scheduler(void) { + uint32_t sp; + uint32_t control; + + asm("mrs %0,msp" : "=&r" (sp)); + asm("msr psp,%0" : : "r" (sp)); + asm("mrs %0,control" : "=&r" (control)); + control |= (1 << 1); + asm("msr control,%0" : : "r" (control)); +} + #define ao_arch_isr_stack() #define ao_arch_wait_interrupt() do { \ |