移植GNU工具链到新的体系架构.doc

移植GNU工具链到新的体系架构字体: 小 中 大 | 打印 发表于: 2008-4-08 20:31 作者: beforewind 来源: EDA中国门户网站 链接地址：/toolchain/toolchain_guide_for_tot.html2007-12-11 从何开始有个新的CPU, 或者新的操作系统,该怎么样搞个tool chain出来? 如何构建一个 self host的操作系统? 或许不为真的要去构造, 仅仅满足一下好奇心而已. 当然打算从gnu toolchain入手, 又不是为了写编译器.(来自互联网的内容已尽力标明出处)tool chain 的结构GCC的tool chain 包括几个部分? 根据印象,应是有gcc,cpp,cc1,gas,ld,gdb, ar, nm,strip,objdump .emulator? 忘了,还有重要的libc. 汗.看一个以上几部分都已经都存在的tool chain的构建,我们需要下面的几个部分才能构建一个完整的tool chain:binutils :gas,ld,ar,nm,strip,objdump.gun-gcc:gcc,cpp,cc1,libc: a c lib for applicationsgdb: for debugging .模拟器.以上各个部分,缺了就不好受.Binutils估计as是我们最想搞到的部分. 没有as,ld,nm,ar. 即使移植了Gcc也是不能工作.binutils包含如下各个部分:主要部分: ld - the GNU linker. as - the GNU assembler.其他(很有用哦): addr2line - Converts addresses into filenames and line numbers. ar - A utility for creating, modifying and extracting from archives. c+filt - Filter to demangle encoded C+ symbols. gprof - Displays profiling information. nlmconv - Converts object code into an NLM. nm - Lists symbols from object files. objcopy - Copys and translates object files. objdump - Displays information from object files. ranlib - Generates an index to the contents of an archive. readelf - Displays information from any ELF format object file. size - Lists the section sizes of an object or archive file. strings - Lists printable strings from files. strip - Discards symbols. windres - A compiler for Windows resource files.预备知识:1.阅读如binutils自己的文档 gas/doc/internals.texi bfd/doc/bfdint.texi Preliminary Notes on Porting BFD2.读源代码.?3.找个cpu的实例来分析,比如这个Add new target to Binutils还有PS3的cell CPU的proting: New port to Cell SPU也比较全面.移植的基本步骤,建议仔细阅读 CGEN, the Cpu tools GENerator 的各种文档:移植完整的Tool chain到一个CPU(target),需要按顺序(不一定,但是这么做是有道理的)移植如下模块: DejaGNUDejaGNU是一个测试工具 DejaGNU的Home Page BFD Binary File DriverPreliminary Notes on Porting BFD CGEN 为GNU tool Chain 提供CPU描述,产生基础文件pcodes, GAS, and simulator,refer to M32R port Opcodes opcodes 目录完全由CGEN产生 CGEN Porting GAS CGEN只产生部分代码,主要是测试 CGEN Porting Binutils ld 搞完ld, binutils就全了. newlib libgloss simulatorCGEN Porting GCC GDB可以看到CGEN的重要作用,困难的Opcodes部分他已经帮着做了. 对于binutils, CGEN为CPU产生如下文件:Opcodes:include/opcodes/FOO.h - Port specific ISA encodingopcodes/FOO-dis.c - Port specific disassembler routinesopcodes/FOO-opc.c - Port specific ISA encodingsize=-1ISA: Instruction Set Architecture . 然后,by hand吧,最头痛的部分可能是BFD/*-Foo.c的编写了,好像是重定位的方式很是不好,RedHat为此搞了一个新的重定位的方式,但是,没有公开.:BFD: bfd/elf32|coff-FOO.c - Port specific relocation handlersbfd/cpu-FOO.c - Port specific description of the CPUGAS:gas/config/tc-FOO.h - Customisation of generic parts of the assemblergas/config/tc-FOO.c - Port specific parts of the assemblerinclude/coff|elf/FOO.h - Port specific header fileLD:ld/scripttempl/FOO.sc - Port specific linker template fileld/emulparam/FOO.sh - Port specific linker customisation最后是各种配置文件的修改:opcodes/configure.inopcodes/disassemble.copcodes/Makefile.ambfd/configure.inbfd/config.bfdbfd/archures.cbfd/reloc.cbfd/targets.cbfd/Makefile.am Run make dep-am.gas/configure.ingas/configure.tgt Add new cpu support.gas/Makefile.am Run make dep-amld/configure.inld/makefile.aminclude/dis-asm.hbinutils/readelf.c: