ELF Binaries and Relocation Entries

Re:ELF Binaries and Relocation Entries by stffrdhrn on Sunday December 01, 2019 @08:37AM (#21675415)

Hello, There are 2 relocations because the series of instructions that needs to create a 32-bit memory address requires HI16 and LO_16 relocations. The 2 relocations sure 16-bit high and low bitfields to compose the 32-bit address.

For a full list of relocation types see the list in the last few links of the article. Note, the OpenRISC relocations are not all well documented.

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Re:ELF Binaries and Relocation Entries by bogomipz on Monday December 02, 2019 @01:19AM (#21680240)

I see, the relocations happen in pairs then - lower order and high order bits. Is that correct?

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Re:ELF Binaries and Relocation Entries by stffrdhrn on Monday December 02, 2019 @06:59AM (#21681671)

Yes, for OpenRISC as there are no instructions with a 32-bit immediate so we use 2 high and low order relocations. However, on machines like x86 they have variable width instructions and support 32-bit relocations, they can get by with a single relocation entry.

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