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Initial crt0 implementation

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Builds but cannot link, missing a lot of symbols
This commit is contained in:
topjohnwu 2024-02-22 16:50:18 -08:00
parent 7e9abe6e90
commit 6d79de7d71
12 changed files with 865 additions and 18 deletions
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7
native/src/Android.mk
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@ -59,11 +59,14 @@ endif
ifdef B_INIT
# -lc -lm is hardcoded in this variable, disable it
TARGET_LDLIBS :=
include $(CLEAR_VARS)
LOCAL_MODULE := magiskinit
LOCAL_STATIC_LIBRARIES := \
crt0 \
libbase \
libcompat \
libpolicy \
libxz \
libinit-rs
@ -87,7 +90,6 @@ include $(CLEAR_VARS)
LOCAL_MODULE := magiskboot
LOCAL_STATIC_LIBRARIES := \
libbase \
libcompat \
liblzma \
liblz4 \
libbz2 \
@ -163,6 +165,7 @@ include $(BUILD_STATIC_LIBRARY)
include src/Android-rs.mk
include src/base/Android.mk
include src/external/Android.mk
include src/crt0/Android.mk
ifdef B_BB

12
native/src/Application.mk
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@ -4,10 +4,20 @@ APP_CFLAGS := -Wall -Oz -fomit-frame-pointer -flto
APP_LDFLAGS := -flto
APP_CPPFLAGS := -std=c++20
APP_STL := none
APP_PLATFORM := android-23
APP_PLATFORM := android-26
APP_THIN_ARCHIVE := true
APP_STRIP_MODE := none
# magiskinit uses crt0
ifdef B_INIT
# Disable all security and debugging features
APP_CFLAGS += -fno-unwind-tables -fno-asynchronous-unwind-tables -fno-stack-protector -U_FORTIFY_SOURCE
# Override output folder to make sure all dependencies are rebuilt with new CFLAGS
NDK_APP_OUT := ./obj/init
endif
# Busybox should use stock libc.a
ifdef B_BB
APP_PLATFORM := android-26

15
native/src/base/Android.mk
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@ -22,18 +22,3 @@ LOCAL_SRC_FILES := \
base-rs.cpp \
../external/cxx-rs/src/cxx.cc
include $(BUILD_STATIC_LIBRARY)
# All static executables should link with libcompat
include $(CLEAR_VARS)
LOCAL_MODULE := libcompat
LOCAL_SRC_FILES := compat/compat.cpp
# Fix static variables' ctor/dtor when using LTO
# See: https://github.com/android/ndk/issues/1461
LOCAL_EXPORT_LDFLAGS := -static -T src/lto_fix.lds -Wl,--wrap=rename -Wl,--wrap=renameat
# For some reason, using the hacky libc.a with x86 will trigger stack protection violation
# when mixing Rust and C++ code. Disable stack protector to bypass this issue.
ifeq ($(TARGET_ARCH), x86)
LOCAL_EXPORT_CFLAGS := -fno-stack-protector
endif
include $(BUILD_STATIC_LIBRARY)

4
native/src/base/logging.cpp
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@ -8,6 +8,10 @@
using namespace std;
#ifndef __call_bypassing_fortify
#define __call_bypassing_fortify(fn) (&fn)
#endif
#undef vsnprintf
static int fmt_and_log_with_rs(LogLevel level, const char *fmt, va_list ap) {
constexpr int sz = 4096;

14
native/src/crt0/Android.mk Normal file
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@ -0,0 +1,14 @@
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := crt0
# Manually link the compiler runtime library
LOCAL_compiler_rt := $(shell $(TARGET_CC) -target $(LLVM_TRIPLE)$(TARGET_PLATFORM_LEVEL) --print-libgcc-file-name)
LOCAL_EXPORT_LDFLAGS := -static -nostartfiles -nodefaultlibs $(LOCAL_compiler_rt)
LOCAL_SRC_FILES := \
nolibc.c
include $(BUILD_STATIC_LIBRARY)

10
native/src/crt0/nolibc.c Normal file
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@ -0,0 +1,10 @@
#include "nolibc/crt.h"
#include "nolibc/arch.h"
// errno
static int g_errno = 0;
int *__errno(void) {
return &g_errno;
}

159
native/src/crt0/nolibc/arch-aarch64.h Normal file
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@ -0,0 +1,159 @@
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* AARCH64 specific definitions for NOLIBC
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
#ifndef _NOLIBC_ARCH_AARCH64_H
#define _NOLIBC_ARCH_AARCH64_H
/* Syscalls for AARCH64 :
* - registers are 64-bit
* - stack is 16-byte aligned
* - syscall number is passed in x8
* - arguments are in x0, x1, x2, x3, x4, x5
* - the system call is performed by calling svc 0
* - syscall return comes in x0.
* - the arguments are cast to long and assigned into the target registers
* which are then simply passed as registers to the asm code, so that we
* don't have to experience issues with register constraints.
*
* On aarch64, select() is not implemented so we have to use pselect6().
*/
#define __ARCH_WANT_SYS_PSELECT6
#define my_syscall0(num) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0"); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall1(num, arg1) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall2(num, arg1, arg2) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall3(num, arg1, arg2, arg3) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
register long _arg4 __asm__ ("x3") = (long)(arg4); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r"(_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
register long _arg4 __asm__ ("x3") = (long)(arg4); \
register long _arg5 __asm__ ("x4") = (long)(arg5); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r" (_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
register long _num __asm__ ("x8") = (num); \
register long _arg1 __asm__ ("x0") = (long)(arg1); \
register long _arg2 __asm__ ("x1") = (long)(arg2); \
register long _arg3 __asm__ ("x2") = (long)(arg3); \
register long _arg4 __asm__ ("x3") = (long)(arg4); \
register long _arg5 __asm__ ("x4") = (long)(arg5); \
register long _arg6 __asm__ ("x5") = (long)(arg6); \
\
__asm__ volatile ( \
"svc #0\n" \
: "=r" (_arg1) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_arg6), "r"(_num) \
: "memory", "cc" \
); \
_arg1; \
})
#ifdef _NOLIBC_CRT_H
/* startup code */
void __attribute__((noreturn)) _start(void)
{
__asm__ volatile (
"mov x0, sp\n" /* save stack pointer to x0, as arg1 of _start_c */
"and sp, x0, -16\n" /* sp must be 16-byte aligned in the callee */
"bl _start_c\n" /* transfer to c runtime */
);
__builtin_unreachable();
}
#endif /* _NOLIBC_CRT_H */
#endif /* _NOLIBC_ARCH_AARCH64_H */

200
native/src/crt0/nolibc/arch-arm.h Normal file
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@ -0,0 +1,200 @@
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* ARM specific definitions for NOLIBC
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
#ifndef _NOLIBC_ARCH_ARM_H
#define _NOLIBC_ARCH_ARM_H
/* Syscalls for ARM in ARM or Thumb modes :
* - registers are 32-bit
* - stack is 8-byte aligned
* ( http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.faqs/ka4127.html)
* - syscall number is passed in r7
* - arguments are in r0, r1, r2, r3, r4, r5
* - the system call is performed by calling svc #0
* - syscall return comes in r0.
* - only lr is clobbered.
* - the arguments are cast to long and assigned into the target registers
* which are then simply passed as registers to the asm code, so that we
* don't have to experience issues with register constraints.
* - the syscall number is always specified last in order to allow to force
* some registers before (gcc refuses a %-register at the last position).
* - in thumb mode without -fomit-frame-pointer, r7 is also used to store the
* frame pointer, and we cannot directly assign it as a register variable,
* nor can we clobber it. Instead we assign the r6 register and swap it
* with r7 before calling svc, and r6 is marked as clobbered.
* We're just using any regular register which we assign to r7 after saving
* it.
*
* Also, ARM supports the old_select syscall if newselect is not available
*/
#define __ARCH_WANT_SYS_OLD_SELECT
#if (defined(__THUMBEB__) || defined(__THUMBEL__)) && \
!defined(NOLIBC_OMIT_FRAME_POINTER)
/* swap r6,r7 needed in Thumb mode since we can't use nor clobber r7 */
#define _NOLIBC_SYSCALL_REG "r6"
#define _NOLIBC_THUMB_SET_R7 "eor r7, r6\neor r6, r7\neor r7, r6\n"
#define _NOLIBC_THUMB_RESTORE_R7 "mov r7, r6\n"
#else /* we're in ARM mode */
/* in Arm mode we can directly use r7 */
#define _NOLIBC_SYSCALL_REG "r7"
#define _NOLIBC_THUMB_SET_R7 ""
#define _NOLIBC_THUMB_RESTORE_R7 ""
#endif /* end THUMB */
#define my_syscall0(num) \
({ \
register long _num __asm__(_NOLIBC_SYSCALL_REG) = (num); \
register long _arg1 __asm__ ("r0"); \
\
__asm__ volatile ( \
_NOLIBC_THUMB_SET_R7 \
"svc #0\n" \
_NOLIBC_THUMB_RESTORE_R7 \
: "=r"(_arg1), "=r"(_num) \
: "r"(_arg1), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall1(num, arg1) \
({ \
register long _num __asm__(_NOLIBC_SYSCALL_REG) = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
\
__asm__ volatile ( \
_NOLIBC_THUMB_SET_R7 \
"svc #0\n" \
_NOLIBC_THUMB_RESTORE_R7 \
: "=r"(_arg1), "=r" (_num) \
: "r"(_arg1), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall2(num, arg1, arg2) \
({ \
register long _num __asm__(_NOLIBC_SYSCALL_REG) = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
\
__asm__ volatile ( \
_NOLIBC_THUMB_SET_R7 \
"svc #0\n" \
_NOLIBC_THUMB_RESTORE_R7 \
: "=r"(_arg1), "=r" (_num) \
: "r"(_arg1), "r"(_arg2), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall3(num, arg1, arg2, arg3) \
({ \
register long _num __asm__(_NOLIBC_SYSCALL_REG) = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
register long _arg3 __asm__ ("r2") = (long)(arg3); \
\
__asm__ volatile ( \
_NOLIBC_THUMB_SET_R7 \
"svc #0\n" \
_NOLIBC_THUMB_RESTORE_R7 \
: "=r"(_arg1), "=r" (_num) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
register long _num __asm__(_NOLIBC_SYSCALL_REG) = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
register long _arg3 __asm__ ("r2") = (long)(arg3); \
register long _arg4 __asm__ ("r3") = (long)(arg4); \
\
__asm__ volatile ( \
_NOLIBC_THUMB_SET_R7 \
"svc #0\n" \
_NOLIBC_THUMB_RESTORE_R7 \
: "=r"(_arg1), "=r" (_num) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
register long _num __asm__(_NOLIBC_SYSCALL_REG) = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
register long _arg3 __asm__ ("r2") = (long)(arg3); \
register long _arg4 __asm__ ("r3") = (long)(arg4); \
register long _arg5 __asm__ ("r4") = (long)(arg5); \
\
__asm__ volatile ( \
_NOLIBC_THUMB_SET_R7 \
"svc #0\n" \
_NOLIBC_THUMB_RESTORE_R7 \
: "=r"(_arg1), "=r" (_num) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
register long _num __asm__(_NOLIBC_SYSCALL_REG) = (num); \
register long _arg1 __asm__ ("r0") = (long)(arg1); \
register long _arg2 __asm__ ("r1") = (long)(arg2); \
register long _arg3 __asm__ ("r2") = (long)(arg3); \
register long _arg4 __asm__ ("r3") = (long)(arg4); \
register long _arg5 __asm__ ("r4") = (long)(arg5); \
register long _arg6 __asm__ ("r5") = (long)(arg6); \
\
__asm__ volatile ( \
_NOLIBC_THUMB_SET_R7 \
"svc #0\n" \
_NOLIBC_THUMB_RESTORE_R7 \
: "=r"(_arg1), "=r" (_num) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_arg6), "r"(_num) \
: "memory", "cc", "lr" \
); \
_arg1; \
})
#ifdef _NOLIBC_CRT_H
/* startup code */
void __attribute__((noreturn)) _start(void)
{
__asm__ volatile (
"mov r0, sp\n" /* save stack pointer to %r0, as arg1 of _start_c */
"and ip, r0, #-8\n" /* sp must be 8-byte aligned in the callee */
"mov sp, ip\n"
"bl _start_c\n" /* transfer to c runtime */
);
__builtin_unreachable();
}
#endif /* _NOLIBC_CRT_H */
#endif /* _NOLIBC_ARCH_ARM_H */

179
native/src/crt0/nolibc/arch-i386.h Normal file
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@ -0,0 +1,179 @@
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* i386 specific definitions for NOLIBC
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
#ifndef _NOLIBC_ARCH_I386_H
#define _NOLIBC_ARCH_I386_H
/* Syscalls for i386 :
* - mostly similar to x86_64
* - registers are 32-bit
* - syscall number is passed in eax
* - arguments are in ebx, ecx, edx, esi, edi, ebp respectively
* - all registers are preserved (except eax of course)
* - the system call is performed by calling int $0x80
* - syscall return comes in eax
* - the arguments are cast to long and assigned into the target registers
* which are then simply passed as registers to the asm code, so that we
* don't have to experience issues with register constraints.
* - the syscall number is always specified last in order to allow to force
* some registers before (gcc refuses a %-register at the last position).
*
* Also, i386 supports the old_select syscall if newselect is not available
*/
#define __ARCH_WANT_SYS_OLD_SELECT
#define my_syscall0(num) \
({ \
long _ret; \
register long _num __asm__ ("eax") = (num); \
\
__asm__ volatile ( \
"int $0x80\n" \
: "=a" (_ret) \
: "0"(_num) \
: "memory", "cc" \
); \
_ret; \
})
#define my_syscall1(num, arg1) \
({ \
long _ret; \
register long _num __asm__ ("eax") = (num); \
register long _arg1 __asm__ ("ebx") = (long)(arg1); \
\
__asm__ volatile ( \
"int $0x80\n" \
: "=a" (_ret) \
: "r"(_arg1), \
"0"(_num) \
: "memory", "cc" \
); \
_ret; \
})
#define my_syscall2(num, arg1, arg2) \
({ \
long _ret; \
register long _num __asm__ ("eax") = (num); \
register long _arg1 __asm__ ("ebx") = (long)(arg1); \
register long _arg2 __asm__ ("ecx") = (long)(arg2); \
\
__asm__ volatile ( \
"int $0x80\n" \
: "=a" (_ret) \
: "r"(_arg1), "r"(_arg2), \
"0"(_num) \
: "memory", "cc" \
); \
_ret; \
})
#define my_syscall3(num, arg1, arg2, arg3) \
({ \
long _ret; \
register long _num __asm__ ("eax") = (num); \
register long _arg1 __asm__ ("ebx") = (long)(arg1); \
register long _arg2 __asm__ ("ecx") = (long)(arg2); \
register long _arg3 __asm__ ("edx") = (long)(arg3); \
\
__asm__ volatile ( \
"int $0x80\n" \
: "=a" (_ret) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), \
"0"(_num) \
: "memory", "cc" \
); \
_ret; \
})
#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
long _ret; \
register long _num __asm__ ("eax") = (num); \
register long _arg1 __asm__ ("ebx") = (long)(arg1); \
register long _arg2 __asm__ ("ecx") = (long)(arg2); \
register long _arg3 __asm__ ("edx") = (long)(arg3); \
register long _arg4 __asm__ ("esi") = (long)(arg4); \
\
__asm__ volatile ( \
"int $0x80\n" \
: "=a" (_ret) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
"0"(_num) \
: "memory", "cc" \
); \
_ret; \
})
#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
long _ret; \
register long _num __asm__ ("eax") = (num); \
register long _arg1 __asm__ ("ebx") = (long)(arg1); \
register long _arg2 __asm__ ("ecx") = (long)(arg2); \
register long _arg3 __asm__ ("edx") = (long)(arg3); \
register long _arg4 __asm__ ("esi") = (long)(arg4); \
register long _arg5 __asm__ ("edi") = (long)(arg5); \
\
__asm__ volatile ( \
"int $0x80\n" \
: "=a" (_ret) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"0"(_num) \
: "memory", "cc" \
); \
_ret; \
})
#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
long _eax = (long)(num); \
long _arg6 = (long)(arg6); /* Always in memory */ \
__asm__ volatile ( \
"pushl %[_arg6]\n\t" \
"pushl %%ebp\n\t" \
"movl 4(%%esp),%%ebp\n\t" \
"int $0x80\n\t" \
"popl %%ebp\n\t" \
"addl $4,%%esp\n\t" \
: "+a"(_eax) /* %eax */ \
: "b"(arg1), /* %ebx */ \
"c"(arg2), /* %ecx */ \
"d"(arg3), /* %edx */ \
"S"(arg4), /* %esi */ \
"D"(arg5), /* %edi */ \
[_arg6]"m"(_arg6) /* memory */ \
: "memory", "cc" \
); \
_eax; \
})
#ifdef _NOLIBC_CRT_H
/* startup code */
/*
* i386 System V ABI mandates:
* 1) last pushed argument must be 16-byte aligned.
* 2) The deepest stack frame should be set to zero
*
*/
void __attribute__((noreturn)) _start(void)
{
__asm__ volatile (
"xor %ebp, %ebp\n" /* zero the stack frame */
"mov %esp, %eax\n" /* save stack pointer to %eax, as arg1 of _start_c */
"and $-16, %esp\n" /* last pushed argument must be 16-byte aligned */
"push %eax\n" /* push arg1 on stack to support plain stack modes too */
"call _start_c\n" /* transfer to c runtime */
"hlt\n" /* ensure it does not return */
);
__builtin_unreachable();
}
#endif /* _NOLIBC_CRT_H */
#endif /* _NOLIBC_ARCH_I386_H */

177
native/src/crt0/nolibc/arch-x86_64.h Normal file
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@ -0,0 +1,177 @@
/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* x86_64 specific definitions for NOLIBC
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
#ifndef _NOLIBC_ARCH_X86_64_H
#define _NOLIBC_ARCH_X86_64_H
/* Syscalls for x86_64 :
* - registers are 64-bit
* - syscall number is passed in rax
* - arguments are in rdi, rsi, rdx, r10, r8, r9 respectively
* - the system call is performed by calling the syscall instruction
* - syscall return comes in rax
* - rcx and r11 are clobbered, others are preserved.
* - the arguments are cast to long and assigned into the target registers
* which are then simply passed as registers to the asm code, so that we
* don't have to experience issues with register constraints.
* - the syscall number is always specified last in order to allow to force
* some registers before (gcc refuses a %-register at the last position).
* - see also x86-64 ABI section A.2 AMD64 Linux Kernel Conventions, A.2.1
* Calling Conventions.
*
* Link x86-64 ABI: https://gitlab.com/x86-psABIs/x86-64-ABI/-/wikis/home
*
*/
#define my_syscall0(num) \
({ \
long _ret; \
register long _num __asm__ ("rax") = (num); \
\
__asm__ volatile ( \
"syscall\n" \
: "=a"(_ret) \
: "0"(_num) \
: "rcx", "r11", "memory", "cc" \
); \
_ret; \
})
#define my_syscall1(num, arg1) \
({ \
long _ret; \
register long _num __asm__ ("rax") = (num); \
register long _arg1 __asm__ ("rdi") = (long)(arg1); \
\
__asm__ volatile ( \
"syscall\n" \
: "=a"(_ret) \
: "r"(_arg1), \
"0"(_num) \
: "rcx", "r11", "memory", "cc" \
); \
_ret; \
})
#define my_syscall2(num, arg1, arg2) \
({ \
long _ret; \
register long _num __asm__ ("rax") = (num); \
register long _arg1 __asm__ ("rdi") = (long)(arg1); \
register long _arg2 __asm__ ("rsi") = (long)(arg2); \
\
__asm__ volatile ( \
"syscall\n" \
: "=a"(_ret) \
: "r"(_arg1), "r"(_arg2), \
"0"(_num) \
: "rcx", "r11", "memory", "cc" \
); \
_ret; \
})
#define my_syscall3(num, arg1, arg2, arg3) \
({ \
long _ret; \
register long _num __asm__ ("rax") = (num); \
register long _arg1 __asm__ ("rdi") = (long)(arg1); \
register long _arg2 __asm__ ("rsi") = (long)(arg2); \
register long _arg3 __asm__ ("rdx") = (long)(arg3); \
\
__asm__ volatile ( \
"syscall\n" \
: "=a"(_ret) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), \
"0"(_num) \
: "rcx", "r11", "memory", "cc" \
); \
_ret; \
})
#define my_syscall4(num, arg1, arg2, arg3, arg4) \
({ \
long _ret; \
register long _num __asm__ ("rax") = (num); \
register long _arg1 __asm__ ("rdi") = (long)(arg1); \
register long _arg2 __asm__ ("rsi") = (long)(arg2); \
register long _arg3 __asm__ ("rdx") = (long)(arg3); \
register long _arg4 __asm__ ("r10") = (long)(arg4); \
\
__asm__ volatile ( \
"syscall\n" \
: "=a"(_ret) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), \
"0"(_num) \
: "rcx", "r11", "memory", "cc" \
); \
_ret; \
})
#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
({ \
long _ret; \
register long _num __asm__ ("rax") = (num); \
register long _arg1 __asm__ ("rdi") = (long)(arg1); \
register long _arg2 __asm__ ("rsi") = (long)(arg2); \
register long _arg3 __asm__ ("rdx") = (long)(arg3); \
register long _arg4 __asm__ ("r10") = (long)(arg4); \
register long _arg5 __asm__ ("r8") = (long)(arg5); \
\
__asm__ volatile ( \
"syscall\n" \
: "=a"(_ret) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"0"(_num) \
: "rcx", "r11", "memory", "cc" \
); \
_ret; \
})
#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
({ \
long _ret; \
register long _num __asm__ ("rax") = (num); \
register long _arg1 __asm__ ("rdi") = (long)(arg1); \
register long _arg2 __asm__ ("rsi") = (long)(arg2); \
register long _arg3 __asm__ ("rdx") = (long)(arg3); \
register long _arg4 __asm__ ("r10") = (long)(arg4); \
register long _arg5 __asm__ ("r8") = (long)(arg5); \
register long _arg6 __asm__ ("r9") = (long)(arg6); \
\
__asm__ volatile ( \
"syscall\n" \
: "=a"(_ret) \
: "r"(_arg1), "r"(_arg2), "r"(_arg3), "r"(_arg4), "r"(_arg5), \
"r"(_arg6), "0"(_num) \
: "rcx", "r11", "memory", "cc" \
); \
_ret; \
})
#ifdef _NOLIBC_CRT_H
/* startup code */
/*
* x86-64 System V ABI mandates:
* 1) %rsp must be 16-byte aligned right before the function call.
* 2) The deepest stack frame should be zero (the %rbp).
*
*/
void __attribute__((noreturn)) _start(void)
{
__asm__ volatile (
"xor %ebp, %ebp\n" /* zero the stack frame */
"mov %rsp, %rdi\n" /* save stack pointer to %rdi, as arg1 of _start_c */
"and $-16, %rsp\n" /* %rsp must be 16-byte aligned before call */
"call _start_c\n" /* transfer to c runtime */
"hlt\n" /* ensure it does not return */
);
__builtin_unreachable();
}
#endif /* _NOLIBC_CRT_H */
#endif /* _NOLIBC_ARCH_X86_64_H */

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/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* Copyright (C) 2017-2022 Willy Tarreau <w@1wt.eu>
*/
/* Below comes the architecture-specific code. For each architecture, we have
* the syscall declarations and the _start code definition. This is the only
* global part. On all architectures the kernel puts everything in the stack
* before jumping to _start just above us, without any return address (_start
* is not a function but an entry point). So at the stack pointer we find argc.
* Then argv[] begins, and ends at the first NULL. Then we have envp which
* starts and ends with a NULL as well. So envp=argv+argc+1.
*/
#ifndef _NOLIBC_ARCH_H
#define _NOLIBC_ARCH_H
#if defined(__x86_64__)
#include "arch-x86_64.h"
#elif defined(__i386__) || defined(__i486__) || defined(__i586__) || defined(__i686__)
#include "arch-i386.h"
#elif defined(__ARM_EABI__)
#include "arch-arm.h"
#elif defined(__aarch64__)
#include "arch-aarch64.h"
#endif
#endif /* _NOLIBC_ARCH_H */

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/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
/*
* C Run Time support for NOLIBC
* Copyright (C) 2023 Zhangjin Wu <falcon@tinylab.org>
*/
#ifndef _NOLIBC_CRT_H
#define _NOLIBC_CRT_H
char **environ;
const unsigned long *_auxv;
void _exit(int);
typedef void init_func_t(int, char*[], char*[]);
typedef void fini_func_t(void);
extern init_func_t *__preinit_array_start[];
extern init_func_t *__preinit_array_end[];
extern init_func_t *__init_array_start[];
extern init_func_t *__init_array_end[];
extern fini_func_t *__fini_array_start[];
extern fini_func_t *__fini_array_end[];
static void call_array(init_func_t **start, init_func_t **end, int argc, char *argv[], char *envp[]) {
unsigned long count = end - start;
while (count-- > 0) {
init_func_t* function = *start++;
(*function)(argc, argv, envp);
}
}
void __attribute__((used)) _start_c(long *sp)
{
long argc;
char **argv;
char **envp;
const unsigned long *auxv;
/* silence potential warning: conflicting types for 'main' */
int _nolibc_main(int, char **, char **) __asm__ ("main");
/*
* sp : argc <-- argument count, required by main()
* argv: argv[0] <-- argument vector, required by main()
* argv[1]
* ...
* argv[argc-1]
* null
* environ: environ[0] <-- environment variables, required by main() and getenv()
* environ[1]
* ...
* null
* _auxv: _auxv[0] <-- auxiliary vector, required by getauxval()
* _auxv[1]
* ...
* null
*/
/* assign argc and argv */
argc = *sp;
argv = (void *)(sp + 1);
/* find environ */
environ = envp = argv + argc + 1;
/* find _auxv */
for (auxv = (void *)envp; *auxv++;)
;
_auxv = auxv;
/* call preinit and init */
call_array(__preinit_array_start, __preinit_array_end, argc, argv, envp);
call_array(__init_array_start, __init_array_end, argc, argv, envp);
/* go to application */
_exit(_nolibc_main(argc, argv, envp));
}
#endif /* _NOLIBC_CRT_H */