[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
ELF header and footer
|
From: |
Danny Milosavljevic |
|
Subject: |
ELF header and footer |
|
Date: |
Tue, 2 Jun 2020 16:19:10 +0200 |
Hi,
in wip-arm, I have lib/linux/arm-mes as completely independent directory.
However, it's quite similar to lib/linux/x86-mes in content.
Summary of diff:
* lib/linux/arm-mes/elf32-footer-single-main.hex2 is identical
* lib/linux/arm-mes/elf32-header.hex2 is almost identical
* lib/linux/x86-mes/elf32-0header.hex2 is almost identical (!!)
* lib/linux/arm-mes/elf32-0hello-mes.hex2 is different-ish
* lib/linux/arm-mes/elf32-body-exit-42.hex2 is different-ish
* lib/linux/arm-mes/elf32-body-hello-mes.hex2 is different-ish
* lib/linux/arm-mes/elf32-0exit-42.hex2 is almost completely different
Diff:
diff -ru lib/linux/x86-mes/elf32-0exit-42.hex2
lib/linux/arm-mes/elf32-0exit-42.hex2
--- lib/linux/x86-mes/elf32-0exit-42.hex2 2020-06-01 21:28:22.903358379
+0200
+++ lib/linux/arm-mes/elf32-0exit-42.hex2 2020-06-02 00:56:17.621474322
+0200
@@ -1,5 +1,6 @@
### GNU Mes --- Maxwell Equations of Software
-### Copyright © 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2019 Danny Milosavljevic <dannym@scratchpost.org>
###
### This file is part of GNU Mes.
###
@@ -18,7 +19,7 @@
### Commentary:
-# elf32-exit-42.hex2: `exit 42' for i686-linux written in hex2 assembly,
+# elf32-exit-42.hex2: `exit 42' for arm-linux written in hex2 assembly,
# for usage with elf32-0header.hex2. This produces a 112-byte binary
# (70 hex). Inspiration was taken from GNU Gcc output of exit-42.S.
@@ -26,9 +27,8 @@
# @60
:ELF_text
-b8 01 00 00 00 # mov $1, %eax
-bb 2a 00 00 00 # mov $42, %ebx
-cd 80 # int $0x80
-f4 # hlt
-00 00 00 # align to @70
+01 70 a0 e3 # mov r7,$0x1
+2a 00 a0 e3 # mov r0,$0x2a
+00 00 00 ef # swi 0
+03 f0 20 e3 # wfi
:ELF_end
diff -ru lib/linux/x86-mes/elf32-0header.hex2
lib/linux/arm-mes/elf32-0header.hex2
--- lib/linux/x86-mes/elf32-0header.hex2 2020-06-01 21:28:22.903358379
+0200
+++ lib/linux/arm-mes/elf32-0header.hex2 2020-06-02 00:56:17.617474310
+0200
@@ -1,5 +1,6 @@
### Copyright (C) 2016 Jeremiah Orians
### Copyright (C) 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2019 Danny Milosavljevic <dannym@scratchpost.org>
###
### This file is part of GNU Mes.
###
@@ -21,14 +22,16 @@
# elf32-0header.hex2: Simplest 32 bit elf header in hex2. Only a text
# segment, no data segment, no symbol tables.
-# stage0's hex2 format for x86
+# stage0's hex2 format for arm
# !<label> 1 byte relative
# $<label> 2 byte address
# @<label> 2 byte relative
+# ~<label> 3 byte relative
# &<label> 4 byte address
# %<label> 4 byte relative
# local_<label> function-local
# string_<index> string #<index>
+# ^ align
### Code:
@@ -45,14 +48,14 @@
00 00 00 00 00 00 00 # e_ident[EI_PAD]
02 00 # e_type Indicating Executable
-03 00 # e_machine Indicating 32bit x86
+28 00 # e_machine Indicating 32bit arm
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
00 00 00 00 # e_shoff Address of section header table
-00 00 00 00 # e_flags
+00 02 00 05 # e_flags Indicating EABI5:
EF_ARM_ABI_FLOAT_SOFT
34 00 # e_ehsize Indicating our 52 Byte header
diff -ru lib/linux/x86-mes/elf32-0hello-mes.hex2
lib/linux/arm-mes/elf32-0hello-mes.hex2
--- lib/linux/x86-mes/elf32-0hello-mes.hex2 2020-06-01 21:28:22.903358379
+0200
+++ lib/linux/arm-mes/elf32-0hello-mes.hex2 2020-06-02 00:56:17.617474310
+0200
@@ -1,5 +1,6 @@
### GNU Mes --- Maxwell Equations of Software
### Copyright © 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright © 2019 Danny Milosavljevic <dannym@scratchpost.org>
###
### This file is part of GNU Mes.
###
@@ -18,7 +19,7 @@
### Commentary:
-# elf32-0hello-mes.hex2: `Hello, GNU Mes!' for i686-linux written in
+# elf32-0hello-mes.hex2: `Hello, GNU Mes!' for arm-linux written in
# hex2 assembly, for usage with elf32-0header.hex2. This produces a
# 160-byte binary (a0 hex). Inspiration was taken from GNU Gcc output
# of hello-mes.S.
@@ -27,22 +28,18 @@
# @60
:ELF_text
-
# print <hello>
-b8 04 00 00 00 # mov $4,%eax
-bb 00 00 00 00 # mov $1,%ebx
-b9 &hello # mov $hello,%ecx
-ba %bye>hello # mov $(bye-hello),%edx
-cd 80 # int $0x80
+04 70 a0 e3 # mov r7, #4
+01 00 a0 e3 # mov r0, #1
+!hello 10 8f e2 # add r1, pc, $(hello - pc)
+!bye>hello 20 a0 e3 # mov r2, $(bye-hello)
+00 00 00 ef # swi 0
# exit 0
-b8 01 00 00 00 # mov $1,%eax
-bb 00 00 00 00 # mov $0,%ebx
-cd 80 # int $0x80
-f4 # hlt
-
-00 00 00 00 00 00 00 00 00 00 # align to @90
-00 00 00
+01 70 a0 e3 # mov r7, #1
+00 00 a0 e3 # mov r0, #0
+00 00 00 ef # swi 0
+03 f0 20 e3 # wfi
# @90
:ELF_data
diff -ru lib/linux/x86-mes/elf32-body-exit-42.hex2
lib/linux/arm-mes/elf32-body-exit-42.hex2
--- lib/linux/x86-mes/elf32-body-exit-42.hex2 2020-06-01 21:28:22.903358379
+0200
+++ lib/linux/arm-mes/elf32-body-exit-42.hex2 2020-06-02 00:56:17.613474298
+0200
@@ -1,5 +1,5 @@
-### GNU Mes --- Maxwell Equations of Software
-### Copyright © 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2019 Danny Milosavljevic <dannym@scratchpost.org>
###
### This file is part of GNU Mes.
###
@@ -18,7 +18,7 @@
### Commentary:
-# elf32-body-exit-42.hex2: `exit 42' for i686-linux written in hex2
+# elf32-body-exit-42.hex2: `exit 42' for arm-linux written in hex2
# assembly, for usage with generic elf32-header.hex2 and
# elf32-footer-single-main.hex.
@@ -30,19 +30,17 @@
# @200
:ELF_text
:_start
-e8 %main # call +11 <main>
-00 00 00
+^~main eb # bl main
+00 00 00 00
00 00 00 00
00 00 00 00
# @210
:main
-bb 2a 00 00 00 # mov $42,%ebx
-b8 01 00 00 00 # mov $0x1,%eax
-cd 80 # int $0x80
-f4 # hlt
-
-00 00 00 # align
+01 70 a0 e3 # mov r7,$0x1
+2a 00 a0 e3 # mov r0,$0x2a
+00 00 00 ef # swi 0
+03 f0 20 e3 # wfi
# @220
:ELF_data
diff -ru lib/linux/x86-mes/elf32-body-hello-mes.hex2
lib/linux/arm-mes/elf32-body-hello-mes.hex2
--- lib/linux/x86-mes/elf32-body-hello-mes.hex2 2020-06-01 21:28:22.903358379
+0200
+++ lib/linux/arm-mes/elf32-body-hello-mes.hex2 2020-06-02 00:56:17.613474298
+0200
@@ -1,5 +1,5 @@
-### GNU Mes --- Maxwell Equations of Software
-### Copyright © 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2019 Danny Milosavljevic <dannym@scratchpost.org>
###
### This file is part of GNU Mes.
###
@@ -18,11 +18,11 @@
### Commentary:
-# elf32-body-hello-mes.hex2: `Hello, GNU Mes!' for i686-linux written in
-# hex2 assembly, for usage with generic elf32-header.hex2 and
+# elf32-body-hello-mes.hex2: `exit 42' for arm-linux written in hex2
+# assembly, for usage with generic elf32-header.hex2 and
# elf32-footer-single-main.hex.
-# This ELF binary contains a symbol table which means that objdump and
+# This ELF binary contains a symbol table, which means that objdump and
# gdb can be used to inspect and debug.
### Code:
@@ -30,34 +30,30 @@
# @200
:ELF_text
:_start
-e8 %main # call +11 <main>
-00 00 00
+^~main eb # bl main
+00 00 00 00
00 00 00 00
00 00 00 00
# @210
:main
# print <hello>
-b8 04 00 00 00 # mov $4, %eax
-bb 00 00 00 00 # mov $1, %ebx
-b9 &hello # mov $hello,%ecx
-ba %bye>hello # mov $(bye-hello),%edx
-cd 80 # int $0x80
+04 70 a0 e3 # mov r7, #4
+01 00 a0 e3 # mov r0, #1
+!hello 10 8f e2 # add r1, pc, $(hello - pc)
+!bye>hello 20 a0 e3 # mov r2, $(bye-hello)
+00 00 00 ef # swi 0
# exit 0
-b8 01 00 00 00 # mov $0x1,%eax
-bb 00 00 00 00 # mov $0,%ebx
-cd 80 # int $0x80
-f4 # hlt
-
-00 00 00 00 00 00 00 00 00 00 # align to @240
-00 00 00
+01 70 a0 e3 # mov r7, #1
+00 00 a0 e3 # mov r0, #0
+00 00 00 ef # swi 0
+03 f0 20 e3 # wfi
-# @240
+# @90
:ELF_data
:hello
48 65 6c 6c 6f 2c 20 47 # Hello, G
4e 55 20 4d 65 73 21 0a # NU Mes!\n
-
:bye
-00
+:ELF_end
diff -ru lib/linux/x86-mes/elf32-footer-single-main.hex2
lib/linux/arm-mes/elf32-footer-single-main.hex2
--- lib/linux/x86-mes/elf32-footer-single-main.hex2 2020-06-01
21:28:22.903358379 +0200
+++ lib/linux/arm-mes/elf32-footer-single-main.hex2 2020-06-02
00:56:17.609474286 +0200
@@ -1,7 +1,8 @@
### Copyright (C) 2017 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2019 Danny Milosavljevic <dannym@scratchpost.org>
### This file is part of stage0.
###
-### stage0 is free software: you can redistribute it and/or modify
+### stage0 is free software: you an 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.
@@ -14,7 +15,7 @@
### You should have received a copy of the GNU General Public License
### along with stage0. If not, see <http://www.gnu.org/licenses/>.
-### stage0's hex2 format for x86
+### stage0's hex2 format for arm
### !<label> 1 byte relative
### $<label> 2 byte address
### @<label> 2 byte relative
diff -ru lib/linux/x86-mes/elf32-header.hex2 lib/linux/arm-mes/elf32-header.hex2
--- lib/linux/x86-mes/elf32-header.hex2 2020-06-01 21:28:22.903358379 +0200
+++ lib/linux/arm-mes/elf32-header.hex2 2020-06-02 00:56:17.609474286 +0200
@@ -1,5 +1,6 @@
### Copyright (C) 2016 Jeremiah Orians
### Copyright (C) 2017,2019 Jan (janneke) Nieuwenhuizen <janneke@gnu.org>
+### Copyright (C) 2019 Danny Milosavljevic <dannym@scratchpost.org>
###
### This file is part of GNU Mes.
###
@@ -21,14 +22,16 @@
# elf32-header.hex2: 32 bit elf header in hex2, with text segment, data
# segment and symbol tables.
-# stage0's hex2 format for x86
+# stage0's hex2 format for arm
# !<label> 1 byte relative
# $<label> 2 byte address
# @<label> 2 byte relative
+# ~<label> 3 byte relative
# &<label> 4 byte address
# %<label> 4 byte relative
# local_<label> function-local
# string_<index> string #<index>
+# ^ align
### Code:
@@ -45,14 +48,14 @@
00 00 00 00 00 00 00 # e_ident[EI_PAD]
02 00 # e_type Indicating Executable
-03 00 # e_machine Indicating 32bit x86
+28 00 # e_machine Indicating 32bit arm
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
+00 02 00 05 # e_flags Indicating EABI5:
EF_ARM_ABI_FLOAT_SOFT
34 00 # e_ehsize Indicating our 52 Byte header
Do we want to share stuff between those, or is it too much work for too little
gain?
pgp52OVw5GuBD.pgp
Description: OpenPGP digital signature
- ELF header and footer,
Danny Milosavljevic <=