Dan Glastonbury djg

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I may be slow to respond.

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Canberra, Australia

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djg / crap3a.crap

Created November 24, 2013 23:36

crap3a.crap - Supports 4 character labels! (written in crap2 dialect)

	#
	# CRAP3a for Darwin-i386-MachO
	# Copyright (C) 2013, Dan Glastonbury <[email protected]>
	#
	# Labels are 4 chars. Labels are stores in a symbol table stored in
	# BSS section. The labels form a list of 32-bit label name and address
	# pairs.
	#
	# Errors are signaled by return code:
	# 1: Syntax Error

djg / crap2b.crap

Created November 24, 2013 23:34

crap2b.crap - crap2a.crap utilizing labels

	#
	# CRAP2b for Darwin-i386-MachO
	# Copyright (C) 2013, Dan Glastonbury <[email protected]>
	#
	# Uses BSS section for data storage and labels for call & jmp targets
	#
	# Based on:
	# HEX2b and HEX2c for Linux-i386-ELF
	# Copyright (C) 2001, Edmund GRIMLEY EVANS <[email protected]>
	#

djg / crap2a.crap

Created November 24, 2013 23:33

crap2a.crap - support for single character labels.

	#
	# CRAP2a for Darwin-i386-MachO
	# Copyright (C) 2013, Dan Glastonbury <[email protected]>
	#
	# Uses BSS section for data storage.
	#
	# Based on:
	# HEX2a for Linux-i386-ELF
	# Copyright (C) 2001, Edmund GRIMLEY EVANS <[email protected]>
	#

djg / crap1.crap

Created November 24, 2013 23:31

crap1.crap - crap0.asm written in crap

	#
	# CRAP1 for Darwin-i386-MachO
	# Copyright (C) 2013, Dan Glastonbury <[email protected]>
	#
	# Based on:
	# HEX1 for Linux-i386-ELF
	# Copyright (C) 2001, Edmund GRIMLEY EVANS <[email protected]>
	#

	# _mach_header: # struct mach_header

djg / crap0.asm

Created November 24, 2013 23:30

crap0 - Level 0 compiler nasm -f bin crap0.asm && chmod +x crap0

	%define STDIN_FILENO 0
	%define STDOUT_FILENO 1

	%define SYS_EXIT 1
	%define SYS_READ 3
	%define SYS_WRITE 4

	USE32
	ORG 0x1000

djg / gist:7611808

Created November 23, 2013 07:13

Forthy stack operations.

	drop:
	pop %ebx
	pop %eax
	jmp *%ebx

	swap:
	pop %ebx
	pop %eax
	pop %ecx
	push %eax

djg / gist:7556935

Created November 20, 2013 02:58

ryg's version: byte count == 22

	# ryg's version
	# getchar:
	31 C0 # xor eax, eax
	50 # push eax
	89 E1 # mov ecx, esp
	50 # push eax
	51 # push ecx
	50 # push eax
	50 # push eax
	B0 03 # mov al, 3

djg / gist:7556865

Created November 20, 2013 02:51

Current byte count == 24

	# getchar: # read a byte from stdin
	6a 00 # push 0
	89 e0 # mov eax, esp
	6a 01 # push 1
	50 # push eax
	6a 00 # push STDIN_FILENO
	6a 03 # push SYS_READ
	58 # pop eax
	50 # push eax
	cd 80 # int 80h

djg / getchar2.asm

Created November 20, 2013 02:50

	; ryg's version
	getchar: ;read a byte from stdin
	xor eax, eax
	push eax
	mov ecx, esp
	push eax
	push ecx
	push eax
	push eax
	mov al, SYS_READ

djg / getchar.asm

Last active December 28, 2015 19:59

I was going for less bytes, hence the push/pop/push shenanigans. There must be an easier way to do this. Why does BSD require the syscall on the top of the stack *and* in EAX?

	getchar: ; read a byte from stdin
	push 0
	mov eax, esp
	push 1
	push eax
	push STDIN_FILENO
	push SYS_READ
	pop eax
	push eax
	int 80h

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