Make: Use -nmagic linker flag #2336
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Previously we told the linker the page size was small so that it would in effect remove any padding between program sections. This was a hack when switching linkers, but the proper way to do this is using the "-nmagic" flag which explicitly tells the linker to not align sections to page sizes. Some relevant discussions: - rust-embedded/cortex-m-quickstart#95 (comment) - #2180 Also copying in the linker docs which might be useful: ``` $ ld.lld --help | grep magic --nmagic Do not page align sections, link against static libraries. --no-nmagic Page align sections (default) --no-omagic Do not set the text data sections to be writable, page align sections (default) -N Alias for --omagic -n Alias for --nmagic --omagic Set the text and data sections to be readable and writable, do not page align sections, link against static libraries ``` Fixes #2219
hudson-ayers
approved these changes
Jan 8, 2021
alistair23
approved these changes
Jan 8, 2021
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Pull Request Overview
This fixes #2219. After looking through the relevant discussions,
--nmagicis the flag I should have used when original converting from gcc to llvm linkers. Setting the page size to a small value was a convenient workaround, but what we really wanted was for there to just not be padding.Also I documented the
-icfflag.Testing Strategy
Comparing kernel binaries before and after this change and verifying they are identical.
TODO or Help Wanted
n/a
Documentation Updated
/docs, or no updates are required.Formatting
make prepush.