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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.
31 lines
1.2 KiB
Plaintext
31 lines
1.2 KiB
Plaintext
/*
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GNU linker script for STM32F439
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*/
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/* Specify the memory areas */
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MEMORY
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{
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FLASH (rx) : ORIGIN = 0x08000000, LENGTH = 2048K /* entire flash */
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FLASH_ISR (rx) : ORIGIN = 0x08000000, LENGTH = 16K /* sector 0 */
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FLASH_TEXT (rx) : ORIGIN = 0x08020000, LENGTH = 896K /* sectors 5-11 are 128K */
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FLASH_FS (rx) : ORIGIN = 0x08100000, LENGTH = 256K /* sectors 12-17 are 4*16K+64K+128K */
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FLASH_FS2 (rx) : ORIGIN = 0x08140000, LENGTH = 128K /* sector 18 */
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RAM (xrw) : ORIGIN = 0x20000000, LENGTH = 192K
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CCMRAM (xrw) : ORIGIN = 0x10000000, LENGTH = 64K
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}
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/* produce a link error if there is not this amount of RAM for these sections */
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_minimum_stack_size = 2K;
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_minimum_heap_size = 16K;
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/* Define the stack. The stack is full descending so begins just above last byte
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of RAM. Note that EABI requires the stack to be 8-byte aligned for a call. */
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_estack = ORIGIN(RAM) + LENGTH(RAM) - _estack_reserve;
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_sstack = _estack - 16K; /* tunable */
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/* RAM extents for the garbage collector */
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_ram_start = ORIGIN(RAM);
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_ram_end = ORIGIN(RAM) + LENGTH(RAM);
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_heap_start = _ebss; /* heap starts just after statically allocated memory */
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_heap_end = _sstack;
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