40 lines
1.1 KiB
ArmAsm
40 lines
1.1 KiB
ArmAsm
.syntax unified
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.text
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.global memset_reg
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.type memset_reg, STT_FUNC
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memset_reg:
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// call with the following (note that the arguments are not validated prior to use):
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// r0 - address of first word to write (inclusive)
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// r1 - address of first word following the address in r0 to NOT write (exclusive)
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// r2 - word value to be written
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// both addresses in r0 and r1 needs to be divisible by 4!
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.L_loop_begin:
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str r2, [r0], 4 // store the word in r2 to the address in r0, post-indexed
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cmp r0, r1
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bne .L_loop_begin
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bx lr
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.global reset_handler
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.type reset_handler, STT_FUNC
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reset_handler:
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ldr r0, =_ram_start // r0 - point to beginning of SRAM
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ldr r1, =_ram_end // r1 - point to byte after the end of SRAM
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ldr r2, =0 // r2 - the byte-sized value to be written
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bl memset_reg
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// copy .data section from flash to SRAM
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ldr r0, =_data // dst addr
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ldr r1, =_data_loadaddr // src addr
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ldr r2, =_data_size // length in bytes
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bl memcpy
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// enter the application code
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bl main
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// loop forever if the application code returns
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b .
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.end
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