29 lines
776 B
ArmAsm
29 lines
776 B
ArmAsm
.global btohex
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.section .rodata
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hexchars:
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.ascii "0123456789ABCDEF"
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.text
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# Convert byte to ASCII hex
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# arguments:
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# a0: value to format
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# temporaries used:
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# t0, t1
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# return:
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# a0: value in ASCII hex
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btohex:
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andi t0, a0, 0xF # Mask off lower nybble
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la a1, hexchars # load address of hexchars
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add a2, a1, t0 # offset to nybble
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lbu t0, 0(a2) # load hex char at offset
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srli t1, a0, 4 # shift upper nybble down
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andi t1, t1, 0xF # mask off upper nybble
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add a2, a1, t1 # offset to nybble
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lbu t1, 0(a2) # load hex char at offset
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mv a0, t1 # copy upper char to a0
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slli a0, a0, 8 # shuft upper char up
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or a0, a0, t0 # OR the lower char into a0
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ret
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