diff options
Diffstat (limited to 'subx')
| -rwxr-xr-x | subx/apps/hex | bin | 11142 -> 11237 bytes | |||
| -rw-r--r-- | subx/apps/hex.subx | 75 |
2 files changed, 66 insertions, 9 deletions
diff --git a/subx/apps/hex b/subx/apps/hex index aaca7324..4f594d95 100755 --- a/subx/apps/hex +++ b/subx/apps/hex Binary files differdiff --git a/subx/apps/hex.subx b/subx/apps/hex.subx index d615a33d..c002864a 100644 --- a/subx/apps/hex.subx +++ b/subx/apps/hex.subx @@ -61,8 +61,8 @@ $run-main: # return convert(Stdin, 1/stdout, 2/stderr, ed) # . . push args 50/push-EAX/ed - 68/push 2/imm32/stderr - 68/push 1/imm32/stdout + 68/push Stderr/imm32 + 68/push Stdout/imm32 68/push Stdin/imm32 # . . call e8/call convert/disp32 @@ -76,12 +76,52 @@ $main:end: # the main entry point convert: # in : (address buffered-file), out : (address buffered-file), err : (address buffered-file), ed : (address exit-descriptor) -> <void> + # pseudocode: + # repeatedly + # EAX = convert-next-hex-byte(in, err, ed) + # if EAX == 0xffffffff break # eof + # write-byte(out, AL) + # flush(out) + # # . prolog 55/push-EBP 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP # . save registers + 50/push-EAX +$convert:loop: + # EAX = convert-next-hex-byte(in, err, ed) + # . . push args + ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x14/disp8 . # push *(EBP+20) + ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0x10/disp8 . # push *(EBP+16) + ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 8/disp8 . # push *(EBP+8) + # . . call + e8/call convert-next-hex-byte/disp32 + # . . discard first 2 args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP + # if EAX == 0xffffffff break + 81 7/subop/compare 3/mod/direct 0/rm32/EAX . . . . . 0xffffffff/imm32 # compare EAX + 74/jump-if-equal $convert:loop-end/disp8 + # write-byte(out, AL) + # . . push args + 50/push-EAX + ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call write-byte/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + # loop + eb/jump $convert:loop/disp8 +$convert:loop-end: + # flush(out) + # . . push args + ff 6/subop/push 1/mod/*+disp8 4/rm32/sib 5/base/EBP 4/index/none . . 0xc/disp8 . # push *(EBP+12) + # . . call + e8/call flush/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP $convert:end: # . restore registers + 58/pop-to-EAX # . epilog 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP 5d/pop-to-EBP @@ -97,10 +137,11 @@ convert-next-hex-byte: # in : (address buffered-file), err : (address buffered- # pseudocode: # EAX = scan-next-byte(in, err, ed) # if (EAX == 0xffffffff) return - # ECX = EAX + # ECX = parse-hex-digit(EAX) # EAX = scan-next-byte(in, err, ed) # if (EAX == 0xffffffff) error("partial byte found.") - # ECX = (ECX << 8) | EAX + # EAX = parse-hex-digit(EAX) + # EAX = (ECX << 4) | EAX # return # # . prolog @@ -120,6 +161,8 @@ convert-next-hex-byte: # in : (address buffered-file), err : (address buffered- # if (EAX == 0xffffffff) return 81 7/subop/compare 3/mod/direct 0/rm32/EAX . . . . . 0xffffffff/imm32 # compare EAX 74/jump-if-equal $convert-next-hex-byte:end/disp8 + # EAX = parse-hex-digit(EAX) + e8/call parse-hex-digit/disp32 # ECX = EAX 89/copy 3/mod/direct 1/rm32/ECX . . . 0/r32/EAX . . # copy EAX to ECX # EAX = scan-next-byte(in, err, ed) @@ -143,9 +186,11 @@ convert-next-hex-byte: # in : (address buffered-file), err : (address buffered- # . . call e8/call error-byte/disp32 # never returns $convert-next-hex-byte:convert: - # EAX = (EAX << 8) | ECX - # . EAX <<= 8 - c1/shift 4/subop/left 3/mod/direct 0/rm32/EAX . . . . . 8/imm8 # shift EAX left by 8 bits + # EAX = parse-hex-digit(EAX) + e8/call parse-hex-digit/disp32 + # EAX = (ECX << 4) | EAX + # . ECX <<= 4 + c1/shift 4/subop/left 3/mod/direct 1/rm32/ECX . . . . . 4/imm8 # shift ECX left by 4 bits # . EAX |= ECX 09/or 3/mod/direct 0/rm32/EAX . . . 1/r32/ECX . . # EAX = bitwise OR with ECX $convert-next-hex-byte:end: @@ -242,10 +287,10 @@ test-convert-next-hex-byte: # return if abort 81 7/subop/compare 1/mod/*+disp8 1/rm32/ECX . . . . 4/disp8 0/imm32 # compare *(ECX+4) 75/jump-if-not-equal $test-convert-next-hex-byte:end/disp8 - # check-ints-equal(EAX, 0x61/a 0x62/b, msg) + # check-ints-equal(EAX, 0xab, msg) # . . push args 68/push "F - test-convert-next-hex-byte"/imm32 - 68/push 0x6261/imm32/ab + 68/push 0xab/imm32/ab 50/push-EAX # . . call e8/call check-ints-equal/disp32 @@ -1528,6 +1573,18 @@ test-hex-above-f: 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 0xc/imm32 # add to ESP c3/return +parse-hex-digit: # in/EAX : byte -> out/EAX : num + # no error checking; accepts argument in EAX + # if EAX <= '9' return EAX - '0' + 3d/compare-EAX 0x39/imm32/9 + 7f/jump-if-greater $parse-hex-digit:else/disp8 + 2d/subtract-from-EAX 0x30/imm32/0 + c3/return +$parse-hex-digit:else: + # otherwise return EAX - 'a' + 10 + 2d/subtract-from-EAX 0x57/imm32/a-10 + c3/return + skip-until-newline: # in : (address buffered-file) -> <void> # pseudocode: # push EAX |