/* 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
_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
        testl %eax,%eax
        jne .exit

        call efi_main                   # call app with "image" and "systab" argument

.exit:  leave
        ret

        // hand-craft a dummy .reloc section so EFI knows it's a relocatable executable:
        // we're using relocation type IMAGE_REL_BASED_ABSOLUTE which is ignored

#define IMAGE_REL_ABSOLUTE      0
        .section .reloc
        .long   0                                       // Page RVA
        .long   12                                      // Block Size (2*4+2*2)
        .word   (IMAGE_REL_ABSOLUTE<<12) +  0
        .word   (IMAGE_REL_ABSOLUTE<<12) +  0