mirror of
https://gitlab.winehq.org/wine/wine-gecko.git
synced 2024-09-13 09:24:08 -07:00
29 lines
1.3 KiB
Plaintext
29 lines
1.3 KiB
Plaintext
Elfhack is a program to optimize ELF binaries for size and cold startup
|
|
speed.
|
|
|
|
Presently, it is quite experimental, though it works well for the target
|
|
it was created for: Firefox's libxul.so.
|
|
|
|
Elfhack currently only does one thing: packing dynamic relocations ;
|
|
which ends up being a quite complex task, that can be summarized this
|
|
way:
|
|
- Remove RELATIVE relocations from the .rel.dyn/.rela.dyn section.
|
|
- Inject a small code able to apply relative relocations "by hand"
|
|
after the .rel.dyn/.rela.dyn section.
|
|
- Inject a section containing relocative relocations in a different
|
|
and more packed format, after the small code.
|
|
- Register the small code as DT_INIT function. Make the small code call
|
|
what was initially the DT_INIT function, if there was one.
|
|
- Remove the hole between the new section containing relative
|
|
relocations and the following sections, adjusting offsets and base
|
|
addresses accordingly.
|
|
- Adjust PT_LOAD entries to fit new offsets, and add an additional
|
|
PT_LOAD entry when that is necessary to handle the discrepancy between
|
|
offsets and base addresses, meaning the section offsets may yet again
|
|
need adjustments.
|
|
- Adjust various DT_* dynamic tags to fit the new ELF layout.
|
|
- Adjust section headers.
|
|
- Adjust ELF headers.
|
|
|
|
See http://glandium.org/blog/?p=1177#relocations for some figures.
|