gnu-efi/gnuefi/crt0-efi-ia64.S
Peter Jones 4f8b339fac 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 08:59:41 -04:00

92 lines
2.8 KiB
ArmAsm

/* crt0-efi-ia64.S - IA-64 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
.psr abi64
.psr lsb
.lsb
.proc _start
_start:
alloc loc0=ar.pfs,2,2,2,0
mov loc1=rp
movl out0=@gprel(ImageBase) // out0 <- ImageBase (ldbase)
;;
add out0=out0,gp
movl out1=@gprel(_DYNAMIC) // out1 <- _DYNAMIC
;; // avoid WAW on CFM
add out1=out1,gp
br.call.sptk.few rp=_relocate
.Lret0:
cmp.ne p6,p0=r0,r8 // r8 == EFI_SUCCESS?
(p6) br.cond.sptk.few .exit // no ->
.Lret1:
mov out0=in0 // image handle
mov out1=in1 // systab
br.call.sptk.few rp=_entry
.Lret2:
.exit:
mov ar.pfs=loc0
mov rp=loc1
;;
br.ret.sptk.few rp
.endp _start
// PE32+ wants a PLABEL, not the code address of the entry point:
.align 16
.global _start_plabel
.section .plabel, "a"
_start_plabel:
data8 _start
data8 __gp
// hand-craft a .reloc section for the plabel:
#define IMAGE_REL_BASED_DIR64 10
.section .reloc, "a"
data4 _start_plabel // Page RVA
data4 12 // Block Size (2*4+2*2), must be aligned by 32 Bits
data2 (IMAGE_REL_BASED_DIR64<<12) + 0 // reloc for plabel's entry point
data2 (IMAGE_REL_BASED_DIR64<<12) + 8 // reloc for plabel's global pointer
#if defined(__ELF__) && defined(__linux__)
.section .note.GNU-stack,"",%progbits
#endif