35 lines
700 B
ArmAsm
35 lines
700 B
ArmAsm
.text
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.global _start // void _start() { ... }
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.type _start, @function
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_start:
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# Initialize global pointer
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.option push
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.option norelax
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setgp:
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auipc gp,%pcrel_hi(__global_pointer$)
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addi gp,gp, %pcrel_lo(setgp)
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.option pop
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# Clear the bss segment (starting at __bss_start and ending at __BSS_END__-1)
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// a0 = __bss_start
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lui a0,%hi(__bss_start)
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addi a0,a0,%lo(__bss_start)
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// a1 = _end
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lui a1,%hi(__BSS_END__)
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addi a1,a1,%lo(__BSS_END__)
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clear_bss:
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bgeu a0,a1,done_bss # while (!(a0 >= a1)) {
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sb x0,0(a0) # *a0 = 0;
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addi a0,a0,1 # ++a0
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beq x0,x0,clear_bss # }
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done_bss:
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ebreak
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.size _start, .-_start
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