mirror of
https://github.com/brain-hackers/lab
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42 lines
646 B
ArmAsm
42 lines
646 B
ArmAsm
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.text
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.arm
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.align 4
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.global _start
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_start:
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stmdb sp!, {r4, lr}
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/* store context */
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movs r4, r0
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/* Clear the .bss section */
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bl .L_clean_bss
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/* restore context */
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adr r0, [.L_context]
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str r4, [r0]
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ldr r0, [r0]
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/* call user's main */
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bl main
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ldmia sp!, {r4, pc}
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.L_context:
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.long 0
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/*
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r0 = start address
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r1 = end address
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tmp: r2
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*/
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.L_clean_bss:
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ldr r0, =__bss_start
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ldr r1, =__bss_end
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sub r1, r1, #4
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mov r2, #0
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.L_clean_bss_loop:
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cmp r0, r1
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strlt r2, [r0], #4
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blt .L_clean_bss_loop
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bx lr
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