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/*-*- mode:unix-assembly; indent-tabs-mode:t; tab-width:8; coding:utf-8 -*-│
vi: set et ft=asm ts=8 tw=8 fenc=utf-8 :vi
Copyright 2020 Justine Alexandra Roberts Tunney
Permission to use, copy, modify, and/or distribute this software for
any purpose with or without fee is hereby granted, provided that the
above copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
*/
#include "libc/macros.h"
/ Tiny Raw Linux Binary Tutorial
/
/ i.e. how to not use cosmopolitan runtimes at all
/ cosmopolitan basically abstracts this
/ except for all major platforms
/
/ make o//examples/raw-linux-hello.elf
/ o/examples/raw-linux-hello.elf # about 6kb
/
/ Next try C but with fancy build tuning
/
/ make -j8 -O \
/ MODE=tiny \
/ LDFLAGS+=-s \
/ CPPFLAGS+=-DIM_FEELING_NAUGHTY \
/ CPPFLAGS+=-DSUPPORT_VECTOR=0b00000001 \
/ o/tiny/examples/hello2.elf
/ o/tiny/examples/hello2.elf # about 8kb
/
/ @param rsp is [n,argv..argvₙ,0,envp..,0,auxv..,0,..]
/ @see also glibc static binaries which start at 800kb!!!
/ @see also go where interfaces sadly disempower ld prune
/ @see also the stl where bad linkage is due to tech debt
/ @note libc/elf/elf.lds can be tinier with page align off
/ @note gas is more powerful than nasm due to rms notation
/ @noreturn
_start: mov $12,%rdx # arg no. 3 is length
getstr "hello world\n",%rsi,%esi # arg no. 2 is memory
mov $1,%edi # arg no. 1 is stdout
mov $1,%eax # write()
syscall # libc/sysv/syscalls.sh
mov $0,%edi # arg no. 1 is success status
mov $0xE7,%eax # exit_group()
syscall # context switch
0: rep nop # basic blockading
jmp 0b
.endfn _start,globl
.source __FILE__