## Copyright (C) 2017 Jeremiah Orians ## This file is part of stage0. ## ## stage0 is free software: you can redistribute it and/or modify ## it under the terms of the GNU General Public License as published by ## the Free Software Foundation, either version 3 of the License, or ## (at your option) any later version. ## ## stage0 is distributed in the hope that it will be useful, ## but WITHOUT ANY WARRANTY; without even the implied warranty of ## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ## GNU General Public License for more details. ## ## You should have received a copy of the GNU General Public License ## along with stage0. If not, see . DEFINE ADDI32_to_R13 4981C5 DEFINE ADDI32_to_RAX 4805 DEFINE ADD_R14_to_RAX 4C01F0 DEFINE ADD_RAX_R14 4C01F0 DEFINE CALLI32 E8 DEFINE CMPI32_R15 4981FF DEFINE CMPI32_RAX 483D DEFINE CMP_R15_Immediate8 4983FF DEFINE CMP_RAX_Immediate8 4883F8 DEFINE COPY_R9_to_RDI 4C89CF DEFINE COPY_R10_to_RDI 4C89D7 DEFINE COPY_RAX_to_R14 4989C6 DEFINE COPY_RAX_to_R9 4989C1 DEFINE COPY_RAX_to_R10 4989C2 DEFINE JE32 0F84 DEFINE JE8 74 DEFINE JGE8 7D DEFINE JL32 0F8C DEFINE JL8 7C DEFINE JMP32 E9 DEFINE JMP8 EB DEFINE JNE32 0F85 DEFINE JNE8 75 DEFINE LOAD32_Address_in_RAX_into_RAX 678B00 DEFINE LOAD8_al_Absolute32 8A0425 DEFINE LOADI32_R13 49C7C5 DEFINE LOADI32_R14 49C7C6 DEFINE LOADI32_R15 49C7C7 DEFINE LOADI32_RAX 48C7C0 DEFINE LOADI32_RDI 48C7C7 DEFINE LOADI32_RDX 48C7C2 DEFINE LOADI32_RSI 48C7C6 DEFINE MOVE_R14_RAX 4989C6 DEFINE MOVZBQ_RAX_AL 480FB6C0 DEFINE NOT_R15 49F7D7 DEFINE NULL 00000000 DEFINE POP_RAX 58 DEFINE POP_RDI 5F DEFINE RET C3 DEFINE RETQ C3 DEFINE SHL8_R14 49C1E6 DEFINE SHL8_RAX 48C1E0 DEFINE SHL_R14_Immediate8 49C1E6 DEFINE STORE32_R13_to_Address_in_RAX 4C8928 DEFINE STORE32_RAX_Absolute32 890425 DEFINE STORE8_al_Absolute32 880425 DEFINE SUBI8_from_RAX 4883E8 DEFINE SUB_R13_from_RAX 4C29E8 DEFINE SUB_RAX_Immediate8 4883E8 DEFINE SYSCALL 0F05 DEFINE TEST_RAX_RAX 4885C0 # Where the ELF Header is going to hit # Simply jump to _start # Our main function :_start POP_RAX #·Get·the·number·of·arguments POP_RDI #·Get·the·program·name POP_RDI #·Get·the·actual·input name LOADI32_RSI %0 #·prepare·read_only LOADI32_RAX %2 #·the·syscall·number·for·open() SYSCALL # Now open that damn file COPY_RAX_to_R9 # Preserve the file pointer we were given POP_RDI #·Get·the·actual·output name LOADI32_RSI %577 # Prepare file as O_WRONLY|O_CREAT|O_TRUNC LOADI32_RDX %448 # Prepare file as RWX for owner only (700 in octal) LOADI32_RAX %2 #·the·syscall·number·for·open() SYSCALL # Now open that damn file COPY_RAX_to_R10 # Preserve the file pointer we were given # Our flag for byte processing LOADI32_R15 %-1 # temp storage for the sum LOADI32_R14 %0 :loop # Read a byte CALLI32 %read_byte # process byte CALLI32 %hex # deal with -1 values CMP_RAX_Immediate8 !0 JL8 !loop # deal with toggle CMP_R15_Immediate8 !0 JGE8 !print # process first byte of pair MOVE_R14_RAX LOADI32_R15 %0 JMP8 !loop # process second byte of pair :print # update the sum and store in output SHL_R14_Immediate8 !4 ADD_RAX_R14 STORE8_al_Absolute32 &output # flip the toggle LOADI32_R15 %-1 CALLI32 %write_byte JMP8 !loop :hex # Purge Comment Lines (#) CMP_RAX_Immediate8 !35 JE8 !purge_comment # Purge Comment Lines (;) CMP_RAX_Immediate8 !59 JE8 !purge_comment # deal all ascii less than '0' CMP_RAX_Immediate8 !48 JL8 !ascii_other # deal with 0-9 CMP_RAX_Immediate8 !58 JL8 !ascii_num # deal with all ascii less than 'A' CMP_RAX_Immediate8 !65 JL8 !ascii_other # deal with 'A'-'F' CMP_RAX_Immediate8 !71 JL8 !ascii_high # deal with all ascii less than 'a' CMP_RAX_Immediate8 !97 JL8 !ascii_other #deal with 'a'-'f' CMP_RAX_Immediate8 !103 JL8 !ascii_low # The rest that remains needs to be ignored JMP8 !ascii_other :purge_comment # Read a byte CALLI32 %read_byte # Loop if not LF CMP_RAX_Immediate8 !10 JNE8 !purge_comment # Otherwise return -1 LOADI32_RAX %-1 RETQ :ascii_num SUB_RAX_Immediate8 !48 RETQ :ascii_low SUB_RAX_Immediate8 !87 RETQ :ascii_high SUB_RAX_Immediate8 !55 RETQ :ascii_other LOADI32_RAX %-1 RETQ :Done # program completed Successfully LOADI32_RDI %0 # All is well LOADI32_RAX %60 # put the exit syscall number in rax SYSCALL # Call it a good day :write_byte # Print our Hex LOADI32_RDX %1 # set the size of chars we want LOADI32_RSI &output # What we are writing COPY_R10_to_RDI # Where are we writing to LOADI32_RAX %1 # the syscall number for write SYSCALL # call the Kernel RET # Where we are putting our output :output # Reserve 4bytes of Zeros NULL :read_byte # Attempt to read 1 byte from STDIN LOADI32_RDX %1 # set the size of chars we want LOADI32_RSI &input # Where to put it COPY_R9_to_RDI # Where are we reading from LOADI32_RAX %0 # the syscall number for read SYSCALL # call the Kernel TEST_RAX_RAX # check what we got JE8 !Done # Got EOF call it done # load byte LOAD8_al_Absolute32 &input # load char MOVZBQ_RAX_AL # We have to zero extend it to use it RET # Where we get our input :input # Reserve 4bytes of Zeros NULL :ELF_end