mirror of https://github.com/ipxe/ipxe.git
fbc4ba4b4e
At some point in the past few years, binutils became more aggressive at removing unused symbols. To function as a symbol requirement, a relocation record must now be in a section marked with @progbits and must not be in a section which gets discarded during the link (either via --gc-sections or via /DISCARD/). Update REQUIRE_SYMBOL() to generate relocation records meeting these criteria. To minimise the impact upon the final binary size, we use existing symbols (specified via the REQUIRING_SYMBOL() macro) as the relocation targets where possible. We use R_386_NONE or R_X86_64_NONE relocation types to prevent any actual unwanted relocation taking place. Where no suitable symbol exists for REQUIRING_SYMBOL() (such as in config.c), the macro PROVIDE_REQUIRING_SYMBOL() can be used to generate a one-byte-long symbol to act as the relocation target. If there are versions of binutils for which this approach fails, then the fallback will probably involve killing off REQUEST_SYMBOL(), redefining REQUIRE_SYMBOL() to use the current definition of REQUEST_SYMBOL(), and postprocessing the linked ELF file with something along the lines of "nm -u | wc -l" to check that there are no undefined symbols remaining. Signed-off-by: Michael Brown <mcb30@ipxe.org> |
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| .. | ||
| defaults | ||
| local | ||
| vbox | ||
| branding.h | ||
| colour.h | ||
| config.c | ||
| config_ethernet.c | ||
| config_fc.c | ||
| config_infiniband.c | ||
| config_net80211.c | ||
| config_romprefix.c | ||
| config_route.c | ||
| config_usb.c | ||
| console.h | ||
| crypto.h | ||
| defaults.h | ||
| dhcp.h | ||
| entropy.h | ||
| general.h | ||
| ioapi.h | ||
| isa.h | ||
| named.h | ||
| nap.h | ||
| reboot.h | ||
| sanboot.h | ||
| serial.h | ||
| settings.h | ||
| sideband.h | ||
| time.h | ||
| timer.h | ||
| umalloc.h | ||