path: root/arch/powerpc/crt_arch.h
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2015-05-22add .text section directive to all crt_arch.h files missing itRich Felker-0/+1
i386 and x86_64 versions already had the .text directive; other archs did not. normally, top-level (file scope) __asm__ starts in the .text section anyway, but problems were reported with some versions of clang, and it seems preferable to set it explicitly anyway, at least for the sake of consistency between archs.
2015-04-13dynamic linker bootstrap overhaulRich Felker-12/+19
this overhaul further reduces the amount of arch-specific code needed by the dynamic linker and removes a number of assumptions, including: - that symbolic function references inside libc are bound at link time via the linker option -Bsymbolic-functions. - that libc functions used by the dynamic linker do not require access to data symbols. - that static/internal function calls and data accesses can be made without performing any relocations, or that arch-specific startup code handled any such relocations needed. removing these assumptions paves the way for allowing itself to be built with stack protector (among other things), and is achieved by a three-stage bootstrap process: 1. relative relocations are processed with a flat function. 2. symbolic relocations are processed with no external calls/data. 3. main program and dependency libs are processed with a fully-functional libc/ldso. reduction in arch-specific code is achived through the following: - crt_arch.h, used for generating crt1.o, now provides the entry point for the dynamic linker too. - asm is no longer responsible for skipping the beginning of argv[] when ldso is invoked as a command. - the functionality previously provided by __reloc_self for heavily GOT-dependent RISC archs is now the arch-agnostic stage-1. - arch-specific relocation type codes are mapped directly as macros rather than via an inline translation function/switch statement.
2013-07-26new mostly-C crt1 implementationRich Felker-0/+12
the only immediate effect of this commit is enabling PIE support on some archs that did not previously have any Scrt1.s, since the existing asm files for crt1 override this C code. so some of the crt_arch.h files committed are only there for the sake of documenting what their archs "would do" if they used the new C-based crt1. the expectation is that new archs should use this new system rather than using heavy asm for crt1. aside from being easier and less error-prone, it also ensures that PIE support is available immediately (since Scrt1.o is generated from the same C source, using -fPIC) rather than having to be added as an afterthought in the porting process.