From 2d8ebfcf633a0e744e49fe14cc0025d8d7d348fc Mon Sep 17 00:00:00 2001 From: Jeff Epler Date: Tue, 10 Nov 2020 10:41:10 -0600 Subject: esp32s2: Correct port_stack_get_top() Closes #3649 --- ports/esp32s2/supervisor/port.c | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/ports/esp32s2/supervisor/port.c b/ports/esp32s2/supervisor/port.c index 0b9c03f74..a25bcce00 100644 --- a/ports/esp32s2/supervisor/port.c +++ b/ports/esp32s2/supervisor/port.c @@ -148,7 +148,18 @@ uint32_t *port_stack_get_limit(void) { } uint32_t *port_stack_get_top(void) { - return port_stack_get_limit() + CONFIG_ESP_MAIN_TASK_STACK_SIZE / (sizeof(uint32_t) / sizeof(StackType_t)); + // The sizeof-arithmetic is so that the pointer arithmetic is done on units + // of uint32_t instead of units of StackType_t. StackType_t is an alias + // for a byte sized type. + // + // The main stack is bigger than CONFIG_ESP_MAIN_TASK_STACK_SIZE -- an + // "extra" size is added to it (TASK_EXTRA_STACK_SIZE). This total size is + // available as ESP_TASK_MAIN_STACK. Presumably TASK_EXTRA_STACK_SIZE is + // additional stack that can be used by the esp-idf runtime. But what's + // important for us is that some very outermost stack frames, such as + // pyexec_friendly_repl, could lie inside the "extra" area and be invisible + // to the garbage collector. + return port_stack_get_limit() + ESP_TASK_MAIN_STACK / (sizeof(uint32_t) / sizeof(StackType_t)); } supervisor_allocation _fixed_stack; -- cgit v1.2.3