diff options
Diffstat (limited to 'apps/ex11.subx')
| -rw-r--r-- | apps/ex11.subx | 355 |
1 files changed, 0 insertions, 355 deletions
diff --git a/apps/ex11.subx b/apps/ex11.subx deleted file mode 100644 index 9ff43a73..00000000 --- a/apps/ex11.subx +++ /dev/null @@ -1,355 +0,0 @@ -# Null-terminated vs size-prefixed ascii strings. -# -# By default we create strings with a 4-byte size prefix rather than a null suffix. -# However we still need null-prefixed strings when interacting with the Linux -# kernel in a few places. This layer implements a function for comparing -# a null-terminated 'kernel string' with a size-prefixed 'SubX string'. -# -# To run: -# $ ./bootstrap translate init.linux apps/ex11.subx -o apps/ex11 -# $ ./bootstrap run apps/ex11 # runs a series of tests -# ...... # all tests pass -# -# (We can't yet run the tests when given a "test" commandline argument, -# because checking for it would require the function being tested! Breakage -# would cause tests to not run, rather than to fail as we'd like.) - -== 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 - -Entry: # run all tests - e8/call run-tests/disp32 # 'run-tests' is a function created automatically by SubX. It calls all functions that start with 'test-'. - # exit(eax) - 89/copy 3/mod/direct 3/rm32/ebx . . . 0/r32/eax . . # copy eax to ebx - e8/call syscall_exit/disp32 - -# compare a null-terminated ascii string with a more idiomatic size-prefixed byte array -# reason for the name: the only place we should have null-terminated ascii strings is from commandline args -kernel-string-equal?: # s: null-terminated ascii string, benchmark: size-prefixed ascii string -> eax: boolean - # pseudocode: - # n = benchmark->size - # s1 = s - # s2 = benchmark->data - # i = 0 - # while i < n - # c1 = *s1 - # c2 = *s2 - # if (c1 == 0) return false - # if (c1 != c2) return false - # ++s1, ++s2, ++i - # return *s1 == 0 - # - # registers: - # i: ecx - # n: edx - # s1: edi - # s2: esi - # c1: eax - # c2: ebx - # - # . prologue - 55/push-ebp - 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp - # . save registers - 51/push-ecx - 52/push-edx - 53/push-ebx - 56/push-esi - 57/push-edi - # s1/edi = s - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 7/r32/edi 8/disp8 . # copy *(ebp+8) to edi - # n/edx = benchmark->size - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 2/r32/edx 0xc/disp8 . # copy *(ebp+12) to edx - 8b/copy 0/mod/indirect 2/rm32/edx . . . 2/r32/edx . . # copy *edx to edx - # s2/esi = benchmark->data - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 6/r32/esi 0xc/disp8 . # copy *(ebp+12) to esi - 81 0/subop/add 3/mod/direct 6/rm32/esi . . . . . 4/imm32 # add to esi - # i/ecx = c1/eax = c2/ebx = 0 - b9/copy-to-ecx 0/imm32/exit - b8/copy-to-eax 0/imm32 - bb/copy-to-ebx 0/imm32 -$kernel-string-equal?:loop: - # if (i >= n) break - 39/compare 3/mod/direct 1/rm32/ecx . . . 2/r32/edx . . # compare ecx with edx - 7d/jump-if->= $kernel-string-equal?:break/disp8 - # c1 = *s1 - 8a/copy-byte 0/mod/indirect 7/rm32/edi . . . 0/r32/AL . . # copy byte at *edi to AL - # c2 = *s2 - 8a/copy-byte 0/mod/indirect 6/rm32/esi . . . 3/r32/BL . . # copy byte at *esi to BL - # if (c1 == 0) return false - 3d/compare-eax-and 0/imm32/null - 74/jump-if-= $kernel-string-equal?:false/disp8 - # if (c1 != c2) return false - 39/compare 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # compare eax and ebx - 75/jump-if-!= $kernel-string-equal?:false/disp8 - # ++i - 41/increment-ecx - # ++s1 - 47/increment-edi - # ++s2 - 46/increment-esi - eb/jump $kernel-string-equal?:loop/disp8 -$kernel-string-equal?:break: - # return *s1 == 0 - 8a/copy-byte 0/mod/indirect 7/rm32/edi . . . 0/r32/AL . . # copy byte at *edi to AL - 3d/compare-eax-and 0/imm32/null - 75/jump-if-!= $kernel-string-equal?:false/disp8 -$kernel-string-equal?:true: - b8/copy-to-eax 1/imm32 - eb/jump $kernel-string-equal?:end/disp8 -$kernel-string-equal?:false: - b8/copy-to-eax 0/imm32 -$kernel-string-equal?:end: - # . restore registers - 5f/pop-to-edi - 5e/pop-to-esi - 5b/pop-to-ebx - 5a/pop-to-edx - 59/pop-to-ecx - # . epilogue - 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp - 5d/pop-to-ebp - c3/return - -# - tests - -test-compare-null-kernel-string-with-empty-array: - # eax = kernel-string-equal?(Null-kernel-string, "") - # . . push args - 68/push ""/imm32 - 68/push Null-kernel-string/imm32 - # . . call - e8/call kernel-string-equal?/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-ints-equal(eax, 1, msg) - # . . push args - 68/push "F - test-compare-null-kernel-string-with-empty-array"/imm32 - 68/push 1/imm32/true - 50/push-eax - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - c3/return - -test-compare-null-kernel-string-with-non-empty-array: - # eax = kernel-string-equal?(Null-kernel-string, "Abc") - # . . push args - 68/push "Abc"/imm32 - 68/push Null-kernel-string/imm32 - # . . call - e8/call kernel-string-equal?/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-ints-equal(eax, 0, msg) - # . . push args - 68/push "F - test-compare-null-kernel-string-with-non-empty-array"/imm32 - 68/push 0/imm32/false - 50/push-eax - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - c3/return - -test-compare-kernel-string-with-equal-array: - # eax = kernel-string-equal?(_test-Abc-kernel-string, "Abc") - # . . push args - 68/push "Abc"/imm32 - 68/push _test-Abc-kernel-string/imm32 - # . . call - e8/call kernel-string-equal?/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-ints-equal(eax, 1, msg) - # . . push args - 68/push "F - test-compare-kernel-string-with-equal-array"/imm32 - 68/push 1/imm32/true - 50/push-eax - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - c3/return - -test-compare-kernel-string-with-inequal-array: - # eax = kernel-string-equal?(_test-Abc-kernel-string, "Adc") - # . . push args - 68/push "Adc"/imm32 - 68/push _test-Abc-kernel-string/imm32 - # . . call - e8/call kernel-string-equal?/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-ints-equal(eax, 0, msg) - # . . push args - 68/push "F - test-compare-kernel-string-with-equal-array"/imm32 - 68/push 0/imm32/false - 50/push-eax - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - c3/return - -test-compare-kernel-string-with-empty-array: - # eax = kernel-string-equal?(_test-Abc-kernel-string, "") - # . . push args - 68/push ""/imm32 - 68/push _test-Abc-kernel-string/imm32 - # . . call - e8/call kernel-string-equal?/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-ints-equal(eax, 0, msg) - # . . push args - 68/push "F - test-compare-kernel-string-with-equal-array"/imm32 - 68/push 0/imm32/false - 50/push-eax - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - c3/return - -test-compare-kernel-string-with-shorter-array: - # eax = kernel-string-equal?(_test-Abc-kernel-string, "Ab") - # . . push args - 68/push "Ab"/imm32 - 68/push _test-Abc-kernel-string/imm32 - # . . call - e8/call kernel-string-equal?/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-ints-equal(eax, 0, msg) - # . . push args - 68/push "F - test-compare-kernel-string-with-shorter-array"/imm32 - 68/push 0/imm32/false - 50/push-eax - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - c3/return - -test-compare-kernel-string-with-longer-array: - # eax = kernel-string-equal?(_test-Abc-kernel-string, "Abcd") - # . . push args - 68/push "Abcd"/imm32 - 68/push _test-Abc-kernel-string/imm32 - # . . call - e8/call kernel-string-equal?/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 8/imm32 # add to esp - # check-ints-equal(eax, 0, msg) - # . . push args - 68/push "F - test-compare-kernel-string-with-longer-array"/imm32 - 68/push 0/imm32/false - 50/push-eax - # . . call - e8/call check-ints-equal/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 0xc/imm32 # add to esp - c3/return - -# - helpers - -# print msg to stderr if a != b, otherwise print "." -check-ints-equal: # (a: int, b: int, msg: (addr array byte)) -> boolean - # . prologue - 55/push-ebp - 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp - # . save registers - 51/push-ecx - 53/push-ebx - # load args into eax, ebx and ecx - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 0/r32/eax 8/disp8 . # copy *(ebp+8) to eax - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 3/r32/ebx 0xc/disp8 . # copy *(ebp+12) to ebx - # if (eax == b/ebx) print('.') and return - 39/compare 3/mod/direct 0/rm32/eax . . . 3/r32/ebx . . # compare eax and ebx - 75/jump-if-unequal $check-ints-equal:else/disp8 - # . write-stderr('.') - # . . push args - 68/push "."/imm32 - # . . call - e8/call write-stderr/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp - # . return - eb/jump $check-ints-equal:end/disp8 - # otherwise print(msg) -$check-ints-equal:else: - # copy msg into ecx - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0x10/disp8 . # copy *(ebp+16) to ecx - # print(ecx) - # . . push args - 51/push-ecx - # . . call - e8/call write-stderr/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp - # print newline - # . . push args - 68/push Newline/imm32 - # . . call - e8/call write-stderr/disp32 - # . . discard args - 81 0/subop/add 3/mod/direct 4/rm32/esp . . . . . 4/imm32 # add to esp -$check-ints-equal:end: - # . restore registers - 5b/pop-to-ebx - 59/pop-to-ecx - # end - 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp - 5d/pop-to-ebp - c3/return - -write-stderr: # s: (addr array byte) -> <void> - # . 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 - 52/push-edx - 53/push-ebx - # syscall(write, 2/stderr, (data) s+4, (size) *s) - # . . fd = 2 (stderr) - bb/copy-to-ebx 2/imm32 - # . . x = s+4 - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 8/disp8 . # copy *(ebp+8) to ecx - 81 0/subop/add 3/mod/direct 1/rm32/ecx . . . . . 4/imm32 # add to ecx - # . . size = *s - 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 2/r32/edx 8/disp8 . # copy *(ebp+8) to edx - 8b/copy 0/mod/indirect 2/rm32/edx . . . 2/r32/edx . . # copy *edx to edx - # . . syscall - e8/call syscall_write/disp32 - # . restore registers - 5b/pop-to-ebx - 5a/pop-to-edx - 59/pop-to-ecx - 58/pop-to-eax - # . end - 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp - 5d/pop-to-ebp - c3/return - -== data - -Newline: - # size - 1/imm32 - # data - 0a/newline - -# for kernel-string-equal tests -Null-kernel-string: - 00/null - -_test-Abc-kernel-string: - 41/A 62/b 63/c 00/null - -# . . vim:nowrap:textwidth=0 |