### Copyright (C) 2016 Jeremiah Orians
### Copyright (C) 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
###
### This file is part of GNU Mes.
###
### GNU Mes is free software; you can redistribute it and/or modify it
### under the terms of the GNU General Public License as published by
### the Free Software Foundation; either version 3 of the License, or (at
### your option) any later version.
###
### GNU Mes is distributed in the hope that it will be useful, but
### WITHOUT ANY WARRANTY; without even the implied warranty of
### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
### GNU General Public License for more details.
###
### You should have received a copy of the GNU General Public License
### along with GNU Mes.  If not, see <http://www.gnu.org/licenses/>.

### Commentary:

# elf32-header.hex2: 32 bit elf header in hex2, with text segment, data
# segment and symbol tables.

# stage0's hex2 format for x86
#    !<label>          1 byte relative
#    $<label>          2 byte address
#    @<label>          2 byte relative
#    &<label>          4 byte address
#    %<label>          4 byte relative
#    local_<label>     function-local
#    string_<index>    string #<index>

### Code:

:ELF_base
7F 45 4C 46                    # e_ident[EI_MAG0-3] ELF's magic number

01                             # e_ident[EI_CLASS] Indicating 32 bit
01                             # e_ident[EI_DATA] Indicating little endianness
01                             # e_ident[EI_VERSION] Indicating original elf

00                             # e_ident[EI_OSABI] Set at 0 because none cares
00                             # e_ident[EI_ABIVERSION] See above

00 00 00 00 00 00 00           # e_ident[EI_PAD]

02 00                          # e_type Indicating Executable
03 00                          # e_machine Indicating 32bit x86
01 00 00 00                    # e_version Indicating original elf

&ELF_text                      # e_entry Address of the entry point
%ELF_program_headers>ELF_base  # e_phoff Address of program header table
%ELF_section_headers>ELF_base  # e_shoff Address of section header table

00 00 00 00                    # e_flags

34 00                          # e_ehsize Indicating our 52 Byte header

20 00                          # e_phentsize size of a program header table
01 00                          # e_phnum number of entries in program table

28 00                          # e_shentsize size of a section header table
07 00                          # e_shnum number of entries in section table

04 00                          # e_shstrndx index of the section names

# @34
00 00 00 00
00 00 00 00
00 00 00 00

# @40
:ELF_program_headers
:ELF_program_header__text
01 00 00 00                    # ph_type: PT-LOAD = 1
00 00 00 00                    # ph_offset
&ELF_base                      # ph_vaddr
&ELF_base                      # ph_physaddr
%ELF_end>ELF_base              # ph_filesz
%ELF_end>ELF_base              # ph_memsz
07 00 00 00                    # ph_flags: PF-X|PF-W|PF-R = 7
01 00 00 00                    # ph_align

# @60
#:ELF_program_header__data     # NOT USED
                               # FIXME: linux 4.17 does not allow this overlap
                               #    Uhuuh, elf segment at 0000000001000000
                               #    requested but the memory is mapped already
01 00 00 00                    # ph_type: PT-LOAD = 1
00 00 00 00                    # ph_offset
&ELF_base                      # ph_vaddr
&ELF_base                      # ph_physaddr
%ELF_end>ELF_base              # ph_filesz
%ELF_end>ELF_base              # ph_memsz
07 00 00 00                    # ph_flags: PF-X|PF-W|PF-R = 7
01 00 00 00                    # ph_align

# @80
:ELF_comment
4d 45 53 00                     # MES
00 00 00 00                     # align
00 00 00 00
00 00 00 00

4d 45 53 00                     # MES
00 00 00 00                     # align
00 00 00 00
00 00 00 00

# @a0
:ELF_shstr
00
:ELF_shstr__text
2e 74 65 78 74 00               # .text
:ELF_shstr__data
2e 64 61 74 61 00               # .data
:ELF_shstr__comment
2e 63 6f 6d 6d 65 6e 74 00      # .comment
:ELF_shstr__shstr
2e 73 68 73 74 72 74 61 62 00   # .shstrtab
:ELF_shstr__sym
2e 73 79 6d 74 61 62 00         # .symtab
:ELF_shstr__str
2e 73 74 72 74 61 62 00         # .strtab

# @d0

:ELF_section_headers
00 00 00 00                     # sh_name
00 00 00 00                     # sh_type
00 00 00 00                     # sh_flags
00 00 00 00                     # sh_addr
00 00 00 00                     # sh_offset
00 00 00 00                     # sh_length
00 00 00 00                     # sh_link
00 00 00 00                     # sh_info
01 00 00 00                     # sh_1?
00 00 00 00                     # sh_entsize

## FIXME: M0 for calculations?
:ELF_section_header_text
%ELF_shstr__text>ELF_shstr      # sh_name
01 00 00 00                     # sh_type = SHT_PROGBITS = 1
06 00 00 00                     # sh_flags = SHF-ALLOC|SHF-EXEC =2 | 4 = 6
&ELF_text                       # sh_addr
%ELF_text>ELF_base              # sh_offset
%ELF_data>ELF_text              # sh_length
00 00 00 00                     # sh_link
00 00 00 00                     # sh_info
01 00 00 00                     # sh_1?
00 00 00 00                     # sh_entsize

:ELF_section_header_data
%ELF_shstr__data>ELF_shstr     # sh_name
01 00 00 00                    # sh_type = SHT_PROGBITS = 1
03 00 00 00                    # sh_flags = SHF-WRITE|SHF-ALLOC = 1 | 2 = 3
&ELF_data                      # sh_addr
%ELF_data>ELF_base             # sh_offset
%ELF_sym>ELF_data              # sh_length
00 00 00 00                    # sh_link
00 00 00 00                    # sh_info
01 00 00 00                    # sh_1?
00 00 00 00                    # sh_entsize

:ELF_section_header_comment
%ELF_shstr__comment>ELF_shstr  # sh_name
01 00 00 00                    # sh_type = SHT_PROGBITS = 1
00 00 00 00                    # sh_flags
&ELF_comment                   # sh_addr
%ELF_comment>ELF_base          # sh_offset
%ELF_shstr>ELF_comment         # sh_length
00 00 00 00                    # sh_link
00 00 00 00                    # sh_info
01 00 00 00                    # sh_1?
00 00 00 00                    # sh_entsize

:ELF_section_header_shstr
%ELF_shstr__shstr>ELF_shstr    # sh_name
03 00 00 00                    # sh_type: str-sht-strtab
00 00 00 00                    # sh_flags
&ELF_shstr                     # sh_addr
%ELF_shstr>ELF_base            # sh_offset
%ELF_section_headers>ELF_shstr # sh_length
00 00 00 00                    # sh_link
00 00 00 00                    # sh_info
01 00 00 00                    # sh_1?
00 00 00 00                    # sh_entsize

:ELF_section_header_sym
%ELF_shstr__sym>ELF_shstr      # sh_name
02 00 00 00                    # sh_type: str-sht-symtab
00 00 00 00                    # sh_flags
&ELF_sym                       # sh_addr
%ELF_sym>ELF_base              # sh_offset
%ELF_end>ELF_sym               # sh_length
06 00 00 00                    # sh_link:6
00 00 00 00                    # sh_info
01 00 00 00                    # sh_1?
10 00 00 00                    # sh_entsize

:ELF_section_header_str
%ELF_shstr__str>ELF_shstr      # sh_name
03 00 00 00                    # sh_type: str-sht-strtab
00 00 00 00                    # sh_flags
&ELF_str                       # sh_addr
%ELF_str>ELF_base              # sh_offset
%ELF_sym>ELF_str               # sh_length
00 00 00 00                    # sh_link
00 00 00 00                    # sh_info
01 00 00 00                    # sh_1?
00 00 00 00                    # sh_entsize

# @1e8
00 00 00 00  # align
00 00 00 00

# @1f0

00 00 00 00  # align
00 00 00 00
00 00 00 00
00 00 00 00

# @200
:ELF_text