04c7cdb668
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.
107 lines
2.3 KiB
Plaintext
107 lines
2.3 KiB
Plaintext
/*
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Linker script for PYBD with STM32F722/STM32F723/STM32F732/STM32F733
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Memory layout for mboot configuration (this here describes the app part):
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FLASH_APP .isr_vector
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FLASH_APP .text
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FLASH_APP .data
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FLASH_EXT .big_const
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RAM .data
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RAM .bss
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RAM .heap
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RAM .stack
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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 = 512K
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FLASH_ISR (rx) : ORIGIN = 0x08000000, LENGTH = 32K /* sectors 0,1 */
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FLASH_APP (rx) : ORIGIN = 0x08008000, LENGTH = 480K /* sectors 2-7 */
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FLASH_EXT (rx) : ORIGIN = 0x90000000, LENGTH = 2048K /* external QSPI */
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RAM (rwx) : ORIGIN = 0x20000000, LENGTH = 256K /* DTCM+SRAM1+SRAM2 */
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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;
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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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ENTRY(Reset_Handler)
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/* Define output sections */
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SECTIONS
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{
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.text_ext :
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{
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. = ALIGN(512);
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*(.big_const*)
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. = ALIGN(4);
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} >FLASH_EXT
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.isr_vector :
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{
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. = ALIGN(4);
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KEEP(*(.isr_vector))
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. = ALIGN(4);
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} >FLASH_APP
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.text :
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{
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. = ALIGN(4);
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*(.text*)
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*(.rodata*)
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. = ALIGN(4);
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_etext = .;
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} >FLASH_APP
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_sidata = LOADADDR(.data);
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.data :
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{
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. = ALIGN(4);
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_sdata = .;
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*(.data*)
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. = ALIGN(4);
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_edata = .;
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} >RAM AT> FLASH_APP
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.bss :
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{
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. = ALIGN(4);
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_sbss = .;
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*(.bss*)
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*(COMMON)
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. = ALIGN(4);
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_ebss = .;
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} >RAM
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.heap :
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{
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. = ALIGN(4);
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. = . + _minimum_heap_size;
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. = ALIGN(4);
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} >RAM
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.stack :
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{
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. = ALIGN(4);
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. = . + _minimum_stack_size;
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. = ALIGN(4);
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} >RAM
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}
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