Revision 196
- Fixed bug where the naked attribute did not work with main
- Used a noreturn attribute to main_start which saved us some room. That works
- Tested removal of interrupt tables, this works
| bootloader.c | ||
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| 1 | 1 |
#include "bootloader.h" |
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// Setup the default fuses |
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/* |
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FUSES = {
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.low = (FUSE_SUT0 & FUSE_CKSEL3 & FUSE_CKSEL2 & FUSE_CKSEL0), |
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.high = (FUSE_EESAVE & FUSE_SPIEN), |
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.extended = (FUSE_SELFPRGEN), |
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}; |
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};*/
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| ... | ... | |
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/** |
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* Where we store the jump to user code. The jump address is in words |
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* due to how the rjmp instruction works. It is 1 word below the bootloader |
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* We declare it as noreturn to save some space since we will never return |
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* to the bootloader unless we do a system reset |
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*/ |
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void (*main_start)(void) = BOOT_START/2 - 1; |
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void (*main_start)(void) __attribute__((noreturn)) = BOOT_START/2 - 1;
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/** |
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* We declare main as naked so that there is no overhead for entering |
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* and returning from this function since we don't really care about |
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* what happens to it after we leave it |
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*/ |
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int main(void) __attribute__ ((naked)); |
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typedef union {
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uint8_t bytes[2]; |
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int16_t sword; |
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} rjump_t; |
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/** |
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* Restore the reset vector to point to the end of ctors. This |
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* is because we are stripping out the interrupt vector table |
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* from the bootloader as we don't use it. |
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*/ |
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void ResetVector (void) __attribute__((naked)) |
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__attribute__((section(".reset")));
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void ResetVector(void) {
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asm("rjmp __ctors_end");
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} |
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// SPM_PAGESIZE is set to 32 bytes |
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void onboard_program_write(uint16_t page, uint8_t *buf) {
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uint16_t i; |
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