I have set up a STM32U5 nucleo board with an additional 8M of memory using an APS6404, following the example in AN5050. Initial setup was straightforward, but trying to create a ThreadX thread that uses an array in that section of memory as its stack isn't working -- local variables within the thread are fine, but function calls like printf("foo") or tx_thread_sleep(10) cause a hard fault.
This is my first project using a STM32 microcontroller, and think I'm missing some fundamental understanding of how this is supposed to work -- any suggestions for what I've missed / what I should try?
------------------ Details about what I'm trying -----------------
After following the steps given in AN5050, I updated my .ld file to create a corresponding memory section:
MEMORY
{
RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 2496K
SRAM4 (xrw) : ORIGIN = 0x28000000, LENGTH = 16K
FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 4096K
OCTOSPI1 (xrw) : ORIGIN = 0x90000000, LENGTH = 8M
}
SECTIONS
{
.octospi1 :
{
. = ALIGN(4);
KEEP(*(.octospi1))
. = ALIGN(4);
} > OCTOSPI1
// [...snip...]
}
Then, I tried to assign a thread's stack to that section:
(This is following the example at https://community.st.com/t5/stm32-mcus/how-to-create-a-thread-using-azurertos-and-stm32cubeide/ta-p/49418, with __attribute__ added)
uint8_t memory_stack[8192] __attribute__((section(".octospi1")));
TX_THREAD memory_thread;
UINT App_ThreadX_Init(VOID *memory_ptr) {
// [...snip...]
ret = tx_thread_create(&memory_thread, "memory demo thread",
memory_thread_entry, 0,
memory_stack, 8192, 4, 1,
TX_NO_TIME_SLICE, TX_AUTO_START);
// [...snip...]
}
Inside memory_thread_entry, individual variables work fine (and I've used the Memory Browser to confirm that they are in the .octospi1 section), but calls to e.g. printf("foo") or tx_thread_sleep(10) cause a hard fault. If I leave out the __attribute__ call in the above code, all calls in the thread work as I expect.
