330 lines
13 KiB
Plaintext
330 lines
13 KiB
Plaintext
### Copyright (C) 2016 Jeremiah Orians
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### This file is part of stage0.
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###
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### stage0 is free software: you can redistribute it and/or modify
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### it under the terms of the GNU General Public License as published by
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### the Free Software Foundation, either version 3 of the License, or
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### (at your option) any later version.
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###
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### stage0 is distributed in the hope that it will be useful,
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### but WITHOUT ANY WARRANTY; without even the implied warranty of
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### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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### GNU General Public License for more details.
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###
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### You should have received a copy of the GNU General Public License
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### along with stage0. If not, see <http://www.gnu.org/licenses/>.
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## ELF Header
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#:ELF_base
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7F 45 4C 46 # e_ident[EI_MAG0-3] ELF's magic number
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01 # e_ident[EI_CLASS] Indicating 32 bit
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01 # e_ident[EI_DATA] Indicating little endianness
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01 # e_ident[EI_VERSION] Indicating original elf
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00 # e_ident[EI_OSABI] Set at 0 because none cares
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00 # e_ident[EI_ABIVERSION] See above
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00 00 00 00 00 00 00 # e_ident[EI_PAD]
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02 00 # e_type Indicating Executable
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03 00 # e_machine Indicating x86
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01 00 00 00 # e_version Indicating original elf
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54 80 04 08 # e_entry Address of the entry point
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34 00 00 00 # e_phoff Address of program header table
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00 00 00 00 # e_shoff Address of section header table
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00 00 00 00 # e_flags
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34 00 # e_ehsize Indicating our 52 Byte header
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20 00 # e_phentsize size of a program header table
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01 00 # e_phnum number of entries in program table
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00 00 # e_shentsize size of a section header table
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00 00 # e_shnum number of entries in section table
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00 00 # e_shstrndx index of the section names
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## Program Header
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#:ELF_program_headers
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#:ELF_program_header__text
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01 00 00 00 # ph_type: PT-LOAD = 1
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00 00 00 00 # ph_offset
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00 80 04 08 # ph_vaddr
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00 80 04 08 # ph_physaddr
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B1 02 00 00 # ph_filesz
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B1 02 00 00 # ph_memsz
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07 00 00 00 # ph_flags: PF-X|PF-W|PF-R = 7
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01 00 00 00 # ph_align
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#:ELF_text
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#:_start
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58 # POP_EAX ;·Get·the·number·of·arguments
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5B # POP_EBX ;·Get·the·program·name
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5B # POP_EBX ;·Get·the·actual·input name
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B9 00000000 # LOADI32_ECX %0 ;·prepare·read_only
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BA 00000000 # LOADI32_EDX %0 ;·extra sure
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B8 05000000 # LOADI32_EAX %5 ;·the·syscall·number·for·open()
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CD80 # INT_80 ; Now open that damn file
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A3 A9820408 # STORE32_Absolute32_eax &fin ; Preserve the file pointer we were given
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5B # POP_EBX ;·Get·the·actual·output name
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B9 41020000 # LOADI32_ECX %577 ; Prepare file as O_WRONLY|O_CREAT|O_TRUNC
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BA C0010000 # LOADI32_EDX %448 ; Prepare file as RWX for owner only (700 in octal)
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B8 05000000 # LOADI32_EAX %5 ;·the·syscall·number·for·open()
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CD80 # INT_80 ; Now open that damn file
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A3 AD820408 # STORE32_Absolute32_eax &fout ; Preserve the file pointer we were given
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BD FFFFFFFF # LOADI32_EBP %-1 ; Our flag for byte processing
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BE 00000000 # LOADI32_ESI %0 ; temp storage for the sum
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BF 00000000 # LOADI32_EDI %0 ; Our starting IP
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E8 %a # CALLI32 %First_pass ; Process it
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; rewind input file
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8B1D A9820408 # LOAD32_Absolute32_ebx &fin ; Using our input file
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B9 00000000 # LOADI32_ECX %0 ; Offset Zero
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BA 00000000 # LOADI32_EDX %0 ; Whence Zero
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B8 13000000 # LOADI32_EAX %19 ; lseek
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CD80 # INT_80
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BD FFFFFFFF # LOADI32_EBP %-1 ; Our flag for byte processing
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BE 00000000 # LOADI32_ESI %0 ; temp storage for the sum
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BF 00000000 # LOADI32_EDI %0 ; Our starting IP
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E8 %g # CALLI32 %Second_pass ; Process it
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E9 %s # JMP32 %Done
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:a #:First_pass
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E8 %t # CALLI32 %Read_byte
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; Deal with EOF
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83F8 FC # CMPI8_EAX !-4
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0F84 %e # JE32 %First_pass_done
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; Check for :
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83F8 3A # CMPI8_EAX !58
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0F85 %b # JNE32 %First_pass_0
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; Deal with label
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E8 %x # CALLI32 %StoreLabel
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:b #:First_pass_0
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; Check for :
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83F8 25 # CMPI8_EAX !37
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0F84 %d # JE32 %First_pass_pointer
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; Deal with everything else
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E8 %f # CALLI32 %hex ; Process our char
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; Deal with EOF
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83F8 FC # CMPI8_EAX !-4
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0F84 %e # JE32 %First_pass_done
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; deal with -1 values
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83F8 00 # CMPI8_EAX !0
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0F8C %a # JL32 %First_pass
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; deal with toggle
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83FD 00 # CMPI8_EBP !0
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0F84 %c # JE32 %First_pass_1
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83C7 01 # ADDI8_EDI !1 ; Increment IP
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:c #:First_pass_1
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F7D5 # NOT_EBP
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E9 %a # JMP32 %First_pass
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:d #:First_pass_pointer
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; Deal with Pointer to label
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E8 %t # CALLI32 %Read_byte ; Drop the char
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83C7 04 # ADDI8_EDI !4 ; Increment IP
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E9 %a # JMP32 %First_pass ; Loop again
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:e #:First_pass_done
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C3 # RET
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:f #:hex
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; deal with EOF
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83F8 FC # CMPI8_EAX !-4
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0F84 %k # JE32 %EOF
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; deal with line comments starting with ;
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83F8 23 # CMPI8_EAX !35
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0F84 %p # JE32 %ascii_comment
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; deal with line comments starting with ;
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83F8 3B # CMPI8_EAX !59
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0F84 %p # JE32 %ascii_comment
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; deal all ascii less than 0
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83F8 30 # CMPI8_EAX !48
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0F8C %o # JL32 %ascii_other
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; deal with 0-9
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83F8 3A # CMPI8_EAX !58
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0F8C %l # JL32 %ascii_num
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; deal with all ascii less than A
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83F8 41 # CMPI8_EAX !65
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0F8C %o # JL32 %ascii_other
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; deal with A-F
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83F8 47 # CMPI8_EAX !71
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0F8C %n # JL32 %ascii_high
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;deal with all ascii less than a
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83F8 61 # CMPI8_EAX !97
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0F8C %o # JL32 %ascii_other
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;deal with a-f
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83F8 67 # CMPI8_EAX !103
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0F8C %m # JL32 %ascii_low
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; The rest that remains needs to be ignored
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E9 %o # JMP32 %ascii_other
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:g #:Second_pass
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E8 %t # CALLI32 %Read_byte
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; Deal with EOF
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83F8 FC # CMPI8_EAX !-4
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0F84 %j # JE32 %Second_pass_done
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; Simply drop the label
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83F8 3A # CMPI8_EAX !58
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0F85 %h # JNE32 %Second_pass_0
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E8 %t # CALLI32 %Read_byte
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E9 %g # JMP32 %Second_pass
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:h #:Second_pass_0
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; Deal with pointer
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83F8 25 # CMPI8_EAX !37
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0F85 %i # JNE32 %Second_pass_1
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E8 %y # CALLI32 %StorePointer
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E9 %g # JMP32 %Second_pass
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:i #:Second_pass_1
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; Deal with everything else
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E8 %f # CALLI32 %hex ; Process our char
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; Deal with EOF
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83F8 FC # CMPI8_EAX !-4
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0F84 %j # JE32 %Second_pass_done
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; deal with -1 values
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83F8 00 # CMPI8_EAX !0
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0F8C %g # JL32 %Second_pass
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; deal with toggle
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83FD 00 # CMPI8_EBP !0
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0F84 %r # JE32 %print
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; process first byte of pair
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89C6 # COPY_EAX_to_ESI
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BD 00000000 # LOADI32_EBP %0
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E9 %g # JMP32 %Second_pass
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:j #:Second_pass_done
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C3 # RET
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:k #:EOF
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C3 # RET
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:l #:ascii_num
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83E8 30 # SUBI8_EAX !48
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C3 # RET
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:m #:ascii_low
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83E8 57 # SUBI8_EAX !87
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C3 # RET
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:n #:ascii_high
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83E8 37 # SUBI8_EAX !55
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C3 # RET
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:o # :ascii_other
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B8 FFFFFFFF # LOADI32_EAX %-1
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C3 # RET
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:p #:ascii_comment
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E8 %t # CALLI32 %Read_byte
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83F8 0D # CMPI8_EAX !13
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0F84 %q # JE32 %ascii_comment_cr
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83F8 0A # CMPI8_EAX !10
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0F85 %p # JNE32 %ascii_comment
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:q #:ascii_comment_cr
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B8 FFFFFFFF # LOADI32_EAX %-1
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C3 # RET
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; process second byte of pair
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:r #:print
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; update the sum and store in output
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C1E6 04 # SHLI8_ESI !4
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01F0 # ADD_ESI_to_EAX
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A2 B1820408 # STORE8_Absolute32_al &table
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; flip the toggle
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F7D5 # NOT_EBP
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; Print our first Hex
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BA 01000000 # LOADI32_EDX %1 ; set the size of chars we want
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E8 %v # CALLI32 %print_chars
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83C7 01 # ADDI8_EDI !1 ; Increment IP
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E9 %g # JMP32 %Second_pass
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:s #:Done
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; program completed Successfully
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BB 00000000 # LOADI32_EBX %0 ; All is well
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B8 01000000 # LOADI32_EAX %1 ; put the exit syscall number in eax
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CD80 # INT_80 ; Call it a good day
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:t #:Read_byte
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; Attempt to read 1 byte from STDIN
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BA 01000000 # LOADI32_EDX %1 ; set the size of chars we want
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B9 B1820408 # LOADI32_ECX &table ; Where to put it
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8B1D A9820408 # LOAD32_Absolute32_ebx &fin ; Where are we reading from
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B8 03000000 # LOADI32_EAX %3 ; the syscall number for read
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CD80 # INT_80 ; call the Kernel
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85C0 # TEST ; check what we got
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0F84 %u # JE32 %Read_byte_1 ; Got EOF call it done
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; load byte
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A0 B1820408 # LOAD8_Absolute32_al &table ; load char
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0FB6C0 # MOVZX ; We have to zero extend it to use it
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C3 # RET
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; Deal with EOF
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:u #:Read_byte_1
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B8 FCFFFFFF # LOADI32_EAX %-4 ; Put EOF in eax
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C3 # RET
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:v #:print_chars
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B9 B1820408 # LOADI32_ECX &table ; What we are writing
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8B1D AD820408 # LOAD32_Absolute32_ebx &fout ; Write to target file
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B8 04000000 # LOADI32_EAX %4 ; the syscall number for write
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CD80 # INT_80 ; call the Kernel
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C3 # RET
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:w #:Get_table_target
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E8 %t # CALLI32 %Read_byte ; Get single char label
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C1E0 02 # SHLI8_EAX !2 ; Each label in table takes 4 bytes to store
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05 B1820408 # ADDI32_EAX &table ; Calculate offset
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C3 # RET
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:x #:StoreLabel
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E8 %w # CALLI32 %Get_table_target
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8938 # STORE32_EDI_into_Address_EAX ; Write out pointer to table
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C3 # RET
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:y #:StorePointer
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83C7 04 # ADDI8_EDI !4 ; Increment IP
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E8 %w # CALLI32 %Get_table_target ; Get address of pointer
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8B00 # LOAD32_Address_EAX_into_EAX ; Get pointer
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29F8 # SUB_EDI_from_EAX ; target - ip
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A3 B1820408 # STORE32_Absolute32_eax &table ; put value in output
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BA 04000000 # LOADI32_EDX %4 ; set the size of chars we want
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E8 %v # CALLI32 %print_chars
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C3 # RET
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#:fin
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00000000 # NULL
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#:fout
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00000000 # NULL
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#:table
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#:ELF_end
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