50 lines
2.7 KiB
ArmAsm
50 lines
2.7 KiB
ArmAsm
/*-*- mode:asm; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
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│vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ This program is free software; you can redistribute it and/or modify │
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│ it under the terms of the GNU General Public License as published by │
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│ the Free Software Foundation; version 2 of the License. │
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│ │
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│ This program is distributed in the hope that it will be useful, but │
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│ WITHOUT ANY WARRANTY; without even the implied warranty of │
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│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
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│ General Public License for more details. │
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│ │
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│ You should have received a copy of the GNU General Public License │
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│ along with this program; if not, write to the Free Software │
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│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
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│ 02110-1301 USA │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/macros.h"
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/ Raw Linux Assembly Binary Tutorial
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/
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/ i.e. how to not use cosmopolitan runtimes at all
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/ cosmopolitan basically abstracts this
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/ except for all major platforms
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/
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/ make o//examples/raw-linux-hello.elf
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/ o//examples/raw-linux-hello.elf # about 6kb
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/
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/ Next consider doing it in C with fancy build tuning
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/
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/ make -j8 -O \
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/ MODE=tiny \
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/ LDFLAGS=-s \
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/ CPPFLAGS=-DSUPPORT_VECTOR=0b00000001 \
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/ o/tiny/examples/hello2.elf
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/ o/tiny/examples/hello2.elf # about 8kb
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/
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/ @noreturn
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_start: mov $12,%rdx # arg no. 3 is length
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getstr "hello world\n",%rsi,%esi # arg no. 2 is memory
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mov $1,%edi # arg no. 1 is stdout
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mov $1,%eax # write()
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syscall # see libc/sysv/syscalls.sh
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mov $0,%edi # arg no. 1 is success status
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mov $0xE7,%eax # exit_group()
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syscall
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.endfn _start,globl
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