Zack Buhman
3bb4740030
The Makefile duplication was done out of laziness; the main Makefile should be rewritten in a similar fashion to this one to allow per-target selection of linker script.
68 lines
1.8 KiB
C
68 lines
1.8 KiB
C
#include <stdint.h>
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extern uint32_t __text_link_start __asm("__text_link_start");
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extern uint32_t __text_link_end __asm("__text_link_end");
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extern uint32_t __text_load_start __asm("__text_load_start");
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extern uint32_t __data_link_start __asm("__data_link_start");
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extern uint32_t __data_link_end __asm("__data_link_end");
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extern uint32_t __data_load_start __asm("__data_load_start");
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extern uint32_t __rodata_link_start __asm("__rodata_link_start");
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extern uint32_t __rodata_link_end __asm("__rodata_link_end");
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extern uint32_t __rodata_load_start __asm("__rodata_load_start");
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extern uint32_t __ctors_link_start __asm("__ctors_link_start");
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extern uint32_t __ctors_link_end __asm("__ctors_link_end");
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extern uint32_t __bss_link_start __asm("__bss_link_start");
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extern uint32_t __bss_link_end __asm("__bss_link_end");
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void copy(uint32_t * start, const uint32_t * end, uint32_t * load)
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__attribute__((section(".text.startup.copy")));
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void copy(uint32_t * start, const uint32_t * end, uint32_t * load)
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{
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if (start != load) {
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while (start < end) {
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*start++ = *load++;
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}
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}
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}
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extern void main(void);
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typedef void(init_t)(void);
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void runtime_init(void)
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__attribute__((section(".text.startup.runtime_init")));
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void runtime_init(void)
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{
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// relocate text (if necessary)
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copy(&__text_link_start, &__text_link_end, &__text_load_start);
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// relocate data (if necessary)
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copy(&__data_link_start, &__data_link_end, &__data_load_start);
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// relocate rodata (if necessary)
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copy(&__rodata_link_start, &__rodata_link_end, &__rodata_load_start);
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uint32_t * start;
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uint32_t * end;
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// clear BSS
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start = &__bss_link_start;
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end = &__bss_link_end;
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while (start < end) {
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*start++ = 0;
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}
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// call ctors
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start = &__ctors_link_start;
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end = &__ctors_link_end;
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while (start < end) {
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((init_t*)(*start++))();
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}
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}
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