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| author | Kartik Agaram <vc@akkartik.com> | 2019-08-20 00:20:38 -0700 |
|---|---|---|
| committer | Kartik Agaram <vc@akkartik.com> | 2019-08-20 00:20:38 -0700 |
| commit | 0bb09d2e14cdf1c1571a8e80ae30460699d00e82 (patch) | |
| tree | 9bcbb8251cab76cc1bd8730ecdf1923a472795ee /apps/random.subx | |
| parent | 668700fd2c48d0380d2e2d1f32faa217ab658fb1 (diff) | |
| download | mu-0bb09d2e14cdf1c1571a8e80ae30460699d00e82.tar.gz | |
5522 - example app: random number stream
Turns out Mu's kernel isn't populating /dev/random correctly.
Diffstat (limited to 'apps/random.subx')
| -rw-r--r-- | apps/random.subx | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/apps/random.subx b/apps/random.subx new file mode 100644 index 00000000..3d7d475e --- /dev/null +++ b/apps/random.subx @@ -0,0 +1,62 @@ +# Repeatedly read 32-bit numbers from /dev/random, print them to stdout. +# +# To run: +# $ ./subx translate 0*.subx apps/random.subx -o apps/random +# $ ./subx run apps/random + +== code 0x09000000 +# 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: + # stream/ESI = syscall(open, "/dev/null", O_RDONLY, 0) # we can't use 'fd' because it looks like a hex byte + bb/copy-to-EBX Filename/imm32 + b9/copy-to-ECX 0/imm32/rdonly + ba/copy-to-EDX 0x180/imm32/fixed-perms + b8/copy-to-EAX 5/imm32/open + cd/syscall 0x80/imm8 + # . stream = EAX + 89/copy 3/mod/direct 6/rm32/ESI . . . 0/r32/EAX . . # copy EAX to ESI + +$loop: + + # syscall(read, Stream, N, 4) + 89/copy 3/mod/direct 3/rm32/EBX . . . 6/r32/ESI . . # copy ESI to EBX + b9/copy-to-ECX N/imm32 + ba/copy-to-EDX 4/imm32/size + b8/copy-to-EAX 3/imm32/read + cd/syscall 0x80/imm8 + + # print-int32-buffered(Stdout, *N) + # . . push args + ff 6/subop/push 0/mod/indirect 5/rm32/.disp32 . . . N/disp32 # push *N + 68/push Stdout/imm32 + # . . call + e8/call print-int32-buffered/disp32 + + # write-buffered(Stdout, Newline) + # . . push args + 68/push Newline/imm32 + 68/push Stdout/imm32 + # . . call + e8/call write-buffered/disp32 + # . . discard args + 81 0/subop/add 3/mod/direct 4/rm32/ESP . . . . . 8/imm32 # add to ESP + + eb/jump $loop/disp8 + + # syscall(exit, 0) + bb/copy-to-EBX 0/imm32 + b8/copy-to-EAX 1/imm32/exit + cd/syscall 0x80/imm8 + +== data 0x0a000000 + +N: + 0/imm32 +Filename: + 2f 64 65 76 2f 72 61 6e 64 6f 6d 00 +# / d e v / r a n d o m null + +# . . vim:nowrap:textwidth=0 |