cosmopolitan/libc/runtime/init.S

145 lines
5.3 KiB
ArmAsm

/*-*- 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
This program is free software; you can redistribute it and/or modify │
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License. │
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of │
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software │
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA
*/
#include "libc/macros.h"
#include "libc/runtime/internal.h"
#include "libc/sysv/consts/prot.h"
#include "libc/dce.h"
.source __FILE__
/ Decentralized function for process initialization.
/
/ Modules may inject cheap data structure initialization code into
/ this function using the .init.start and .init.end macros. That
/ code can use the LODS and STOS instructions to initialize memory
/ that's restricted to read-only after initialization by PIRO.
/
/ This is fast, since the linker is able to roll-up initialization
/ for large codebases comprised of many modules, into a perfectly
/ linear order. It also enables a common pattern we use, which we
/ call Referencing Is Initialization (RII).
/
/ C/C++ code should favor using ordinary constructors, since under
/ normal circumstances the compiler will clobber RDI and RSI which
/ are granted special meanings within this function.
/
/ @param r12 is argc (still callee saved)
/ @param r13 is argv (still callee saved)
/ @param r14 is envp (still callee saved)
/ @param r15 is envp (still callee saved)
/ @note rdi is __init_bss_start (callee monotonic lockstep)
/ @note rsi is __init_rodata_start (callee monotonic lockstep)
/ @see .init.start & .init.end (libc/macros.internal.inc)
/ @see ape/ape.lds
.section .initprologue,"ax",@progbits
.type _init,@function
.globl _init
_init: push %rbp
mov %rsp,%rbp
.profilable
ezlea __init_bss_start,di
ezlea __init_rodata_start,si
.previous/*
...
decentralized content
...
*/.section .initepilogue,"ax",@progbits
#if IsModeDbg()
_init_check_rdi_rsi:
jmp 2f
1: call abort
2: ezlea __init_bss_end,ax
cmp %rax,%rdi
jne 1b
ezlea __init_rodata_end,ax
cmp %rax,%rsi
jne 1b
3: .endfn _init_check_rdi_rsi
#endif
_woot: leave
ret
.previous
/ Decentralized section for packed data structures & initializers.
/
/ @see .initro (libc/macros.internal.inc)
/ @see ape/ape.lds
.section .initroprologue,"a",@progbits
.type __init_rodata_start,@object
.type __init_rodata_end,@object
.globl __init_rodata_start,__init_rodata_end
.hidden __init_rodata_start,__init_rodata_end
.align __SIZEOF_POINTER__
__init_rodata_start:
.previous/*
...
decentralized content
...
*/.section .initroepilogue,"a",@progbits
__init_rodata_end:
.byte 0x90
.previous
/ Decentralized section for unpacked data structures.
/
/ Data in this section becomes read-only after initialization.
/
/ @see .piro.bss.init (libc/macros.internal.inc)
/ @see libc/runtime/piro.c
/ @see ape/ape.lds
.section .piro.bss.init.1,"aw",@nobits
.type __init_bss_start,@object
.type __init_bss_end,@object
.globl __init_bss_start,__init_bss_end
.hidden __init_bss_start,__init_bss_end
.align __SIZEOF_POINTER__
__init_bss_start:
.previous/*
...
decentralized content
...
*/.section .piro.bss.init.3,"aw",@nobits
__init_bss_end:
.byte 0
.previous
/ Special area for Windows NT support code.
/
/ Isolating this code adds value for Windows users by minimizing
/ page faults through improved locality. On System Five the PIRO
/ runtime can unmap these pages.
/
/ @see libc/runtime/piro.c
/ @see ape/ape.lds
.section .textwindowsprologue,"ax",@progbits
.type __text_windows_start,@object
.type __text_windows_end,@object
.globl __text_windows_start,__text_windows_end
.hidden __text_windows_start,__text_windows_end
int3
__text_windows_start:
.previous/*
...
decentralized content
...
*/.section .textwindowsepilogue,"ax",@progbits
__text_windows_end:
int3
.previous