cosmopolitan/ape/loader-macho.S
Justine Tunney 40eb3b9d5d
Fully support OpenBSD 7.3
This change (1) upgrades to OpenBSD's newer kernel ABIs, and (2)
modifies APE to have a read-only data segment. Doing this required
creating APE Loader v1.1, which is backwards and forwards compatible
with the previous version.

If you've run the following commands in the past to install your APE
Loader systemwide, then you need to run them again. Ad-hoc installations
shouldn't be impacted. It's also recommended that APE binaries be remade
after upgrading, since they embed old versions of the APE Loader.

    ape/apeuninstall.sh
    ape/apeinstall.sh

This change does more than just fix OpenBSD. The new loader is smarter
and more reliable. We're now able create much tinier ELF and Mach-O data
structures than we could before. Both APE Loader and execvpe() will now
normalize ambiguous argv[0] resolution the same way as the UNIX shell.
Badness with TLS linkage has been solved.

Fixes #826
2023-07-01 18:14:27 -07:00

110 lines
4 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 2021 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/macho.internal.h"
#include "libc/sysv/consts/prot.h"
#include "libc/dce.h"
#include "libc/macros.internal.h"
// APE Loader Executable Structure for XNU
.section .head
.balign 64
macho: .long 0xFEEDFACE+1
.long MAC_CPU_NEXGEN32E
.long MAC_CPU_NEXGEN32E_ALL
.long MAC_EXECUTE
.long 4 // number of load commands
.long 50f-10f // size of all load commands
.long MAC_NOUNDEFS // flags
.long 0 // reserved
10: .long MAC_LC_SEGMENT_64
.long 20f-10b // unmaps first page dir
.ascin "__PAGEZERO",16 // consistent with linux
.quad 0,0x200000,0,0 // which forbids mem <2m
.long 0,0,0,0
20: .long MAC_LC_SEGMENT_64
.long 30f-20b
.ascin "__TEXT",16
.quad macho // vaddr
.quad filesz // memsz
.quad 0 // file offset
.quad filesz // file size
.long PROT_EXEC|PROT_READ|PROT_WRITE // maxprot
.long PROT_EXEC|PROT_READ // initprot
.long 0 // segment section count
.long 0 // flags
30: .long MAC_LC_UUID
.long 40f-30b
.quad 0x3fb29ee4ac6c87aa // uuid1
.quad 0xdd2c9bb866d9eef8 // uuid2
40: .long MAC_LC_UNIXTHREAD
.long 50f-40b // cmdsize
.long MAC_THREAD_NEXGEN32E // flavaflav
.long (420f-410f)/4 // count
410: .quad 0 // rax
.quad 0 // rbx
.quad 0 // rcx
.quad 0 // rdx
.quad 0 // rdi
.quad 0 // rsi
.quad 0 // rbp
.quad 0 // rsp
.quad 0 // r8
.quad 0 // r9
.quad 0 // r10
.quad 0 // r11
.quad 0 // r12
.quad 0 // r13
.quad 0 // r14
.quad 0 // r15
.quad _start // rip
.quad 0 // rflags
.quad 0 // cs
.quad 0 // fs
.quad 0 // gs
420:
50:
.endobj macho,globl
.balign 64
_start: mov $_HOSTXNU,%dl // xnu's not unix!
mov %rsp,%rsi // save real stack
sub $1024*1024,%rsp // room for allocs
jmp ApeLoader
.endfn _start,globl
// Invokes system call.
//
// This function has eight parameters. The first seven are for
// arguments passed along to the system call. The eight is for
// the magic number that indicates which system call is called
//
// The return value follows the Linux kernel convention, where
// errors are returned as `-errno`. BSD systems are normalized
// to follow this convention automatically.
SystemCall:
mov %rcx,%r10
mov 16(%rsp),%eax
clc
syscall
jnc 1f
neg %rax
1: ret
.endfn SystemCall,globl