Welcome to the Linux Foundation Forum!
ELF header
linuxdudex10
Posts: 38
what is the ELF header for an executable linux binary
0
Comments
-
Have you attempted to use "readelf -h {executable file}" to examine the elf headers for various files to compare the data in the headers?0
-
All an ELF header *really* does is explain to the kernel a little bit about what the file is and what it does, and what it's for. That is to say, is it an executable, or a library? Is it for my architecture, or other architecture? Assuming it's an executable for my architecture, how much memory should I reserve for this thing? What other bits of data should I load into memory? Does it require my to load any other libraries?
Pretty much all operating systems today require some kind of header like this on executables. Windows uses one called PE. The most recent example I can think of where this was not the case was the old .com executable format for DOS where the code in a .com file was meant to be run on bare metal (e.g. no memory management from the OS, and little or no functionality from the OS other than the interupts it may have overwritten in memory). The requirement for access to more and more memory, and the need for multitasking and interaction with services provided by an OS had lead to these executable headers.
ELF happens to be a very portable / popular standard. It's an Open format available to any OS / Platform, and specifically provides a way to embed information about the intended platform of the code that is universally readable. A lot of OSs and platforms today use ELF or some variation of ELF.
Wikipedia has a decent enough article about ELF.
Also, you can read the man pages for readelf, objdump, file, and magic for a little more information.
Basically, the ELF header is built by the linker when you are building software (man ld)0
Categories
- All Categories
- 60 LFX Mentorship
- 113 LFX Mentorship: Linux Kernel
- 616 Linux Foundation IT Professional Programs
- 321 Cloud Engineer IT Professional Program
- 141 Advanced Cloud Engineer IT Professional Program
- 55 DevOps Engineer IT Professional Program
- 67 Cloud Native Developer IT Professional Program
- 6 Express Training Courses
- 6 Express Courses - Discussion Forum
- 2.3K Training Courses
- 19 LFC110 Class Forum - Discontinued
- 9 LFC131 Class Forum
- 31 LFD102 Class Forum
- 174 LFD103 Class Forum
- 22 LFD121 Class Forum
- 2 LFD137 Class Forum
- 61 LFD201 Class Forum
- 2 LFD210 Class Forum
- 1 LFD210-CN Class Forum
- 1 LFD213 Class Forum - Discontinued
- 128 LFD232 Class Forum - Discontinued
- LFD237 Class Forum
- 23 LFD254 Class Forum
- 653 LFD259 Class Forum
- 108 LFD272 Class Forum
- 1 LFD272-JP クラス フォーラム
- 4 LFD273 Class Forum
- 2 LFS145 Class Forum
- 28 LFS200 Class Forum
- 740 LFS201 Class Forum - Discontinued
- 1 LFS201-JP クラス フォーラム
- 12 LFS203 Class Forum
- 92 LFS207 Class Forum
- 301 LFS211 Class Forum
- 54 LFS216 Class Forum
- 47 LFS241 Class Forum
- 41 LFS242 Class Forum
- 37 LFS243 Class Forum
- 12 LFS244 Class Forum
- 41 LFS250 Class Forum
- 1 LFS250-JP クラス フォーラム
- LFS251 Class Forum
- 142 LFS253 Class Forum
- LFS254 Class Forum
- LFS255 Class Forum
- LFS256 Class Forum
- LFS257 Class Forum
- 1.2K LFS258 Class Forum
- 10 LFS258-JP クラス フォーラム
- 106 LFS260 Class Forum
- 145 LFS261 Class Forum
- 39 LFS262 Class Forum
- 83 LFS263 Class Forum - Discontinued
- 15 LFS264 Class Forum - Discontinued
- 11 LFS266 Class Forum - Discontinued
- 20 LFS267 Class Forum
- 18 LFS268 Class Forum
- 26 LFS269 Class Forum
- 204 LFS272 Class Forum
- 1 LFS272-JP クラス フォーラム
- LFS274 Class Forum
- 3 LFS281 Class Forum
- 249 LFW211 Class Forum
- 177 LFW212 Class Forum
- 9 SKF100 Class Forum
- SKF200 Class Forum
- 907 Hardware
- 220 Drivers
- 74 I/O Devices
- 44 Monitors
- 116 Multimedia
- 210 Networking
- 102 Printers & Scanners
- 86 Storage
- 764 Linux Distributions
- 88 Debian
- 66 Fedora
- 15 Linux Mint
- 13 Mageia
- 24 openSUSE
- 143 Red Hat Enterprise
- 33 Slackware
- 13 SUSE Enterprise
- 357 Ubuntu
- 482 Linux System Administration
- 40 Cloud Computing
- 70 Command Line/Scripting
- Github systems admin projects
- 95 Linux Security
- 80 Network Management
- 108 System Management
- 51 Web Management
- 71 Mobile Computing
- 24 Android
- 32 Development
- 1.2K New to Linux
- 1.1K Getting Started with Linux
- 545 Off Topic
- 132 Introductions
- 223 Small Talk
- 22 Study Material
- 831 Programming and Development
- 282 Kernel Development
- 515 Software Development
- 974 Software
- 260 Applications
- 185 Command Line
- 3 Compiling/Installing
- 119 Games
- 318 Installation
- 65 All In Program
- 65 All In Forum
Upcoming Training
-
August 20, 2018
Kubernetes Administration (LFS458)
-
August 20, 2018
Linux System Administration (LFS301)
-
August 27, 2018
Open Source Virtualization (LFS462)
-
August 27, 2018
Linux Kernel Debugging and Security (LFD440)