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gnu-efi/gnuefi/crt0-efi-ia32.S

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Initial commit gnu-efi_3.0r
2013-01-31 01:25:25 +04:00
/* crt0-efi-ia32.S - x86 EFI startup code.
Copyright (C) 1999 Hewlett-Packard Co.
Contributed by David Mosberger <davidm@hpl.hp.com>.
All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
* Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
* Redistributions in binary form must reproduce the above
copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials
provided with the distribution.
* Neither the name of Hewlett-Packard Co. nor the names of its
contributors may be used to endorse or promote products derived
from this software without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS
BE LIABLE FOR ANYDIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
*/
.text
.align 4
.globl _start
Mark _start as function Currently marked as NOTYPE Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
2023-06-07 17:50:04 +03:00
.type _start,%function
Initial commit gnu-efi_3.0r
2013-01-31 01:25:25 +04:00
_start:
pushl %ebp
movl %esp,%ebp
pushl 12(%ebp) # copy "image" argument
pushl 8(%ebp) # copy "systab" argument
call 0f
0: popl %eax
movl %eax,%ebx
addl $ImageBase-0b,%eax # %eax = ldbase
addl $_DYNAMIC-0b,%ebx # %ebx = _DYNAMIC
pushl %ebx # pass _DYNAMIC as second argument
pushl %eax # pass ldbase as first argument
call _relocate
popl %ebx
popl %ebx
Make ELF constructors and destructors work This makes setup and teardown functions defined with __attribute__((__constructor__) and __attribute__((__destructor__)) work in normal circumstances in EFI binaries. A couple of notes: - it implements both the old-style .ctors/.dtors methods and the newer style .init_array/.fini_array ELF constructor and destructor arrays, processed in the order: .init_array[] .ctors[] efi_main() .dtors[] .fini_array[] - Destructors will only be called if efi_main() exits using "return"; any call to Exit() will still longjmp() past them. - InitializeLib() has already been called before constructors run, so they don't need to call it (and neither does anything else.) For compatibility, it has been altered so calling it more than once is safe. - No attempt is made to handle any constructor or destructor with a prototype other than "void func(void);", but note that InitializeLib has been called, so LibImageHandle, ST, BS, and RT are set. - The init_array/ctor/dtor/fini_array lists aren't the using the GNU "CONSTRUCTOR" output section command, so they don't start with a size. - The lists are individually sorted during the link stage via SORT_BY_NAME() in the linker script. - The default (empty) init_array/ctor/dtor/fini_array lists are padded out to 8-byte alignment with ".p2align 3, 0", and each list always has at least one ".long 0" at the end of it (even if it's completely empty). As a result, they can have NULLs that need to be skipped. The sections they're in are mergeable, so the NULLs don't have to be exclusively at the end. - The ia64 and mips64el arches have not been tested. Signed-off-by: Peter Jones <pjones@redhat.com>
2023-03-28 15:28:40 +03:00
testl %eax,%eax
jne .exit
Initial commit gnu-efi_3.0r
2013-01-31 01:25:25 +04:00
Make ELF constructors and destructors work This makes setup and teardown functions defined with __attribute__((__constructor__) and __attribute__((__destructor__)) work in normal circumstances in EFI binaries. A couple of notes: - it implements both the old-style .ctors/.dtors methods and the newer style .init_array/.fini_array ELF constructor and destructor arrays, processed in the order: .init_array[] .ctors[] efi_main() .dtors[] .fini_array[] - Destructors will only be called if efi_main() exits using "return"; any call to Exit() will still longjmp() past them. - InitializeLib() has already been called before constructors run, so they don't need to call it (and neither does anything else.) For compatibility, it has been altered so calling it more than once is safe. - No attempt is made to handle any constructor or destructor with a prototype other than "void func(void);", but note that InitializeLib has been called, so LibImageHandle, ST, BS, and RT are set. - The init_array/ctor/dtor/fini_array lists aren't the using the GNU "CONSTRUCTOR" output section command, so they don't start with a size. - The lists are individually sorted during the link stage via SORT_BY_NAME() in the linker script. - The default (empty) init_array/ctor/dtor/fini_array lists are padded out to 8-byte alignment with ".p2align 3, 0", and each list always has at least one ".long 0" at the end of it (even if it's completely empty). As a result, they can have NULLs that need to be skipped. The sections they're in are mergeable, so the NULLs don't have to be exclusively at the end. - The ia64 and mips64el arches have not been tested. Signed-off-by: Peter Jones <pjones@redhat.com>
2023-03-28 15:28:40 +03:00
call _entry # call app with "image" and "systab" argument
Initial commit gnu-efi_3.0r
2013-01-31 01:25:25 +04:00
.exit: leave
Make ELF constructors and destructors work This makes setup and teardown functions defined with __attribute__((__constructor__) and __attribute__((__destructor__)) work in normal circumstances in EFI binaries. A couple of notes: - it implements both the old-style .ctors/.dtors methods and the newer style .init_array/.fini_array ELF constructor and destructor arrays, processed in the order: .init_array[] .ctors[] efi_main() .dtors[] .fini_array[] - Destructors will only be called if efi_main() exits using "return"; any call to Exit() will still longjmp() past them. - InitializeLib() has already been called before constructors run, so they don't need to call it (and neither does anything else.) For compatibility, it has been altered so calling it more than once is safe. - No attempt is made to handle any constructor or destructor with a prototype other than "void func(void);", but note that InitializeLib has been called, so LibImageHandle, ST, BS, and RT are set. - The init_array/ctor/dtor/fini_array lists aren't the using the GNU "CONSTRUCTOR" output section command, so they don't start with a size. - The lists are individually sorted during the link stage via SORT_BY_NAME() in the linker script. - The default (empty) init_array/ctor/dtor/fini_array lists are padded out to 8-byte alignment with ".p2align 3, 0", and each list always has at least one ".long 0" at the end of it (even if it's completely empty). As a result, they can have NULLs that need to be skipped. The sections they're in are mergeable, so the NULLs don't have to be exclusively at the end. - The ia64 and mips64el arches have not been tested. Signed-off-by: Peter Jones <pjones@redhat.com>
2023-03-28 15:28:40 +03:00
ret
Initial commit gnu-efi_3.0r
2013-01-31 01:25:25 +04:00
// hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
.data
Avoid processor dependent sizes in assembly .word -> .2byte .short -> .2byte .long -> .4byte .quad -> .8byte Reference: https://github.com/rhboot/gnu-efi/commit/b83f0845b556506265d25d6a839a23c77b037ae4 Fixes: https://sourceforge.net/p/gnu-efi/bugs/37/ Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
2023-05-20 15:37:04 +03:00
dummy: .4byte 0
Initial commit gnu-efi_3.0r
2013-01-31 01:25:25 +04:00
#define IMAGE_REL_ABSOLUTE 0
.section .reloc
Avoid processor dependent sizes in assembly .word -> .2byte .short -> .2byte .long -> .4byte .quad -> .8byte Reference: https://github.com/rhboot/gnu-efi/commit/b83f0845b556506265d25d6a839a23c77b037ae4 Fixes: https://sourceforge.net/p/gnu-efi/bugs/37/ Signed-off-by: Callum Farmer <gmbr3@opensuse.org>
2023-05-20 15:37:04 +03:00
.4byte dummy // Page RVA
.4byte 12 // Block Size (2*4+2*2), must be aligned by 32 Bits
.2byte (IMAGE_REL_ABSOLUTE<<12) + 0 // reloc for dummy
.2byte (IMAGE_REL_ABSOLUTE<<12) + 0 // reloc for dummy
*/*.S: add non-executable GNU stack marking on ELF-linux binutils-2.39 enabed a few warning by default (https://sourceware.org/pipermail/binutils/2022-August/122246.html): > The ELF linker will now generate a warning message if the stack is made executable. Let's suppress the warnings in assembly files by adding non-executables stack markings. This fixes at least systemd build which uses '-Wl,--fatal-warnings': https://github.com/systemd/systemd/issues/24226
2022-08-06 13:16:29 +03:00
#if defined(__ELF__) && defined(__linux__)
.section .note.GNU-stack,"",%progbits
#endif