circuitpython/ports/stm32/boards/stm32l432.ld
Damien George 04c7cdb668 stm32: Enter bootloader via a system reset.
Entering a bootloader (ST system bootloader, or custom mboot) from software
by directly branching to it is not reliable, and the reliability of it
working can depend on the peripherals that were enabled by the application
code.  It's also not possible to branch to a bootloader if the WDT is
enabled (unless the bootloader has specific provisions to feed the WDT).

This patch changes the way a bootloader is entered from software by first
doing a complete system reset, then branching to the desired bootloader
early on in the start-up process.  The top two words of RAM (of the stack)
are reserved to store flags indicating that the bootloader should be
entered after a reset.
2019-06-25 14:15:49 +10:00

28 lines
913 B
Plaintext

/*
GNU linker script for STM32L432KC
*/
/* Specify the memory areas */
MEMORY
{
FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 256K
FLASH_TEXT (rx) : ORIGIN = 0x08000000, LENGTH = 256K
RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 48K
SRAM2 (xrw) : ORIGIN = 0x10000000, LENGTH = 16K
}
/* produce a link error if there is not this amount of RAM for these sections */
_minimum_stack_size = 2K;
_minimum_heap_size = 16K;
/* Define the stack. The stack is full descending so begins just above last byte
of RAM. Note that EABI requires the stack to be 8-byte aligned for a call. */
_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
_sstack = _estack - 6K; /* tunable */
/* RAM extents for the garbage collector */
_ram_start = ORIGIN(RAM);
_ram_end = ORIGIN(RAM) + LENGTH(RAM);
_heap_start = _ebss; /* heap starts just after statically allocated memory */
_heap_end = _sstack;