1 # Print an error message followed by the text representation of a byte. Then exit. 2 3 == code 4 # instruction effective address register displacement immediate 5 # . op subop mod rm32 base index scale r32 6 # . 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 7 8 #? Entry: # manual test 9 #? # . var ed/EAX : exit-descriptor 10 #? 81 5/subop/subtract 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # subtract from ESP 11 #? 89/copy 3/mod/direct 0/rm32/EAX . . . 4/r32/ESP . . # copy ESP to EAX 12 #? # . configure ed to really exit() 13 #? # . . ed->target = 0 14 #? c7 0/subop/copy 0/mod/direct 0/rm32/EAX . . . . . 0/imm32 # copy to *EAX 15 #? # . error-byte(ed, Stdout, msg, 34) 16 #? 68/push 0x34/imm32 17 #? 68/push "abc"/imm32 18 #? 68/push Stderr/imm32 19 #? 50/push-EAX 20 #? e8/call error-byte/disp32 21 #? # . syscall(exit, Num-test-failures) 22 #? 8b/copy 0/mod/indirect 5/rm32/.disp32 . . 3/r32/EBX Num-test-failures/disp32 # copy *Num-test-failures to EBX 23 #? b8/copy-to-EAX 1/imm32/exit 24 #? cd/syscall 0x80/imm8 25 26 # write(out, "Error: "+msg+": "+byte) then stop(ed, 1) 27 error-byte: # ed : (address exit-descriptor), out : (address buffered-file), msg : (address array byte), n : byte -> <void> 28 # . prolog 29 55/push-EBP 30 89/copy 3/mod/direct 5/rm32/EBP . . . 4/r32/ESP . . # copy ESP to EBP 31 # write-buffered(out, "Error: ") 32 # . . push args 33 68/push "Error: "/imm32 34 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) 35 # . . call 36 e8/call write-buffered/disp32 37 # . . discard args 38 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP 39 # write-buffered(out, msg) 40 # . . push args 41 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x10/disp8 . # push *(EBP+16) 42 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) 43 # . . call 44 e8/call write-buffered/disp32 45 # . . discard args 46 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP 47 # write-buffered(out, ": ") 48 # . . push args 49 68/push ": "/imm32 50 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) 51 # . . call 52 e8/call write-buffered/disp32 53 # . . discard args 54 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP 55 # print-byte-buffered(out, byte) 56 # . . push args 57 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0x14/disp8 . # push *(EBP+20) 58 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) 59 # . . call 60 e8/call print-byte-buffered/disp32 61 # . . discard args 62 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP 63 # write-buffered(out, Newline) 64 # . . push args 65 68/push Newline/imm32 66 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) 67 # . . call 68 e8/call write-buffered/disp32 69 # . . discard args 70 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP 71 # . flush(out) 72 # . . push args 73 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 0xc/disp8 . # push *(EBP+12) 74 # . . call 75 e8/call flush/disp32 76 # . . discard args 77 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 4/imm32 # add to ESP 78 # stop(ed, 1) 79 # . . push args 80 68/push 1/imm32 81 ff 6/subop/push 1/mod/*+disp8 5/rm32/EBP . . . . 8/disp8 . # push *(EBP+8) 82 # . . call 83 e8/call stop/disp32 84 # should never get past this point 85 $error-byte:dead-end: 86 # . epilog 87 89/copy 3/mod/direct 4/rm32/ESP . . . 5/r32/EBP . . # copy EBP to ESP 88 5d/pop-to-EBP 89 c3/return 90 91 == data 92 93 # The buffered file for standard error. 94 Stderr: 95 # file descriptor or (address stream) 96 2/imm32 # standard error 97 # current write index 98 0/imm32 99 # current read index 100 0/imm32 101 # length 102 8/imm32 103 # data 104 00 00 00 00 00 00 00 00 # 8 bytes 105 106 # TODO: 8 bytes is too small. We'll need to grow the buffer for efficiency. But 107 # I don't want to type in 1024 bytes here. 108 109 # . . vim:nowrap:textwidth=0