diff options
Diffstat (limited to 'baremetal/117write-int-hex.subx')
| -rw-r--r-- | baremetal/117write-int-hex.subx | 202 |
1 files changed, 0 insertions, 202 deletions
diff --git a/baremetal/117write-int-hex.subx b/baremetal/117write-int-hex.subx deleted file mode 100644 index 091bd874..00000000 --- a/baremetal/117write-int-hex.subx +++ /dev/null @@ -1,202 +0,0 @@ -# Write out the (hex) textual representation of numbers. - -== code -# instruction effective address register displacement immediate -# . op subop mod rm32 base index scale r32 -# . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes - -# convert the lowest nibble of eax to ascii and return it in the lowest byte of eax -to-hex-char: # in/eax: int -> out/eax: int - # no error checking; accepts argument in eax - # if (eax <= 9) return eax + '0' - 3d/compare-eax-with 0x9/imm32/9 - 7f/jump-if-> $to-hex-char:else/disp8 - 05/add-to-eax 0x30/imm32/0 - c3/return -$to-hex-char:else: - # otherwise return eax + 'a' - 10 - 05/add-to-eax 0x57/imm32/a-10 - c3/return - -append-byte-hex: # f: (addr stream byte), n: int - # . prologue - 55/push-ebp - 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp - # . save registers - 50/push-eax - # AL = convert upper nibble to hex - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0xc/disp8 . # copy *(ebp+12) to eax - c1/shift 5/subop/logic-right 3/mod/direct 0/rm32/eax . . . . . 4/imm8 # shift eax right by 4 bits, while padding zeroes - 25/and-eax 0xf/imm32 - # . AL = to-hex-char(AL) - e8/call to-hex-char/disp32 - # append-byte(f, AL) - # . . push args - 50/push-eax - ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) - # . . call - e8/call append-byte/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # AL = convert lower nibble to hex - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0xc/disp8 . # copy *(ebp+12) to eax - 25/and-eax 0xf/imm32 - # . AL = to-hex-char(AL) - e8/call to-hex-char/disp32 - # append-byte(f, AL) - # . . push args - 50/push-eax - ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) - # . . call - e8/call append-byte/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp -$append-byte-hex:end: - # . restore registers - 58/pop-to-eax - # . epilogue - 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp - 5d/pop-to-ebp - c3/return - -test-append-byte-hex: - # - check that append-byte-hex adds the hex textual representation - # setup - # . clear-stream(_test-stream) - # . . push args - 68/push _test-stream/imm32 - # . . call - e8/call clear-stream/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp - # append-byte-hex(_test-stream, 0xa) # exercises digit, non-digit as well as leading zero - # . . push args - 68/push 0xa/imm32 - 68/push _test-stream/imm32 - # . . call - e8/call append-byte-hex/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-stream-equal(_test-stream, "0a", msg) - # . . push args - 68/push "F - test-append-byte-hex"/imm32 - 68/push "0a"/imm32 - 68/push _test-stream/imm32 - # . . call - e8/call check-stream-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - # . end - c3/return - -write-int32-hex: # f: (addr stream byte), n: int - # . prologue - 55/push-ebp - 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp -$write-int32-hex:hex-prefix: - # write(f, "0x") - # . . push args - 68/push "0x"/imm32 - ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) - # . . call - e8/call write/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp -$write-int32-hex:rest: - # write-int32-hex-bits(f, n, 32) - # . . push args - 68/push 0x20/imm32 - ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 0xc/disp8 . # push *(ebp+12) - ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) - # . . call - e8/call write-int32-hex-bits/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp -$write-int32-hex:end: - # . epilogue - 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp - 5d/pop-to-ebp - c3/return - -# print rightmost 'bits' of 'n' -# bits must be multiple of 4 -write-int32-hex-bits: # f: (addr stream byte), n: int, bits: int - # pseudocode: - # bits -= 4 - # while true - # if (bits < 0) break - # eax = n >> bits - # eax = eax & 0xf - # append-byte(f, AL) - # bits -= 4 - # - # . prologue - 55/push-ebp - 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp - # . save registers - 50/push-eax - 51/push-ecx - # ecx = bits-4 - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0x10/disp8 . # copy *(ebp+16) to ecx - 81 5/subop/subtract 3/mod/direct 1/rm32/ecx . . . . . 4/imm32 # subtract from ecx -$write-int32-hex-bits:loop: - # if (bits < 0) break - 81 7/subop/compare 3/mod/direct 1/rm32/ecx . . . . . 0/imm32 # compare ecx - 7c/jump-if-< $write-int32-hex-bits:end/disp8 - # eax = n >> bits - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 0xc/disp8 . # copy *(ebp+12) to eax - d3/>>ecx 5/subop/pad-zeroes 3/mod/direct 0/rm32/eax . . . . . . # shift eax right by ecx bits, padding zeroes - # eax = to-hex-char(AL) - 25/and-eax 0xf/imm32 - e8/call to-hex-char/disp32 - # append-byte(f, AL) - # . . push args - 50/push-eax - ff 6/subop/push 1/mod/*+disp8 5/rm32/ebp . . . . 8/disp8 . # push *(ebp+8) - # . . call - e8/call append-byte/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # bits -= 4 - 81 5/subop/subtract 3/mod/direct 1/rm32/ecx . . . . . 4/imm32 # subtract from ecx - eb/jump $write-int32-hex-bits:loop/disp8 -$write-int32-hex-bits:end: - # . restore registers - 59/pop-to-ecx - 58/pop-to-eax - # . epilogue - 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp - 5d/pop-to-ebp - c3/return - -test-write-int32-hex: - # - check that write-int32-hex prints the hex textual representation - # setup - # . clear-stream(_test-stream) - # . . push args - 68/push _test-stream/imm32 - # . . call - e8/call clear-stream/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp - # write-int32-hex(_test-stream, 0x8899aa) - # . . push args - 68/push 0x8899aa/imm32 - 68/push _test-stream/imm32 - # . . call - e8/call write-int32-hex/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-stream-equal(_test-stream, "0x008899aa", msg) - # . . push args - 68/push "F - test-write-int32-hex"/imm32 - 68/push "0x008899aa"/imm32 - 68/push _test-stream/imm32 - # . . call - e8/call check-stream-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - # . end - c3/return - -# . . vim:nowrap:textwidth=0 |