diff options
| -rw-r--r-- | docs/PORTING | 26 |
1 files changed, 15 insertions, 11 deletions
diff --git a/docs/PORTING b/docs/PORTING index 1c58c0ca3..a4c01423c 100644 --- a/docs/PORTING +++ b/docs/PORTING @@ -1,20 +1,22 @@ -Some notes to help future porters. Replace 'ARCH' with whatever arch +Some notes to help future porters. Replace 'ARCH' with whatever arch you are hacking on. ==================== === Config Files === ==================== - create extra/Configs/Config.ARCH - See the other arch files for some good examples. powerpc/sparc/alpha + See the other arch files for some good examples. powerpc/sparc/alpha should be pretty simple templates. - add ARCH to the 'Target Architecture' list in extra/Configs/Config.in -- for now, disable shared libraries - add HAVE_NO_SHARED and ARCH_HAS_NO_LDSO to Config.ARCH's HAVE_ELF +- Initially you will want to disable shared libraries, since making + the shared library loader work requires you first have basic architecture + support working. Thus you should add HAVE_NO_SHARED and ARCH_HAS_NO_LDSO + to Config.ARCH's HAVE_ELF ==================== === libc sysdeps === ==================== -(note: if glibc has already been ported to your arch, you can usually just +(note: if glibc has already been ported to your arch, you can usually just copy a lot of files from them rather than coding from scratch) - create libc/sysdeps/linux/ARCH - copy Makefile and Makefile.arch from libc/sysdeps/linux/i386/ @@ -24,9 +26,9 @@ you are hacking on. to clear the frame pointer to make gdb happy, and then you will want to call the funcion __uClibc_main() which takes these parameters: __uClibc_main(main(), argc, argv, _init(), _fini()) - for now, you can disable the UCLIBC_CTOR_DTOR option and just set those two - arguments to NULL - glibc stores this function in libc/sysdeps/ARCH/elf/start.S + Initially if you wish to make things easier on yourself, you can disable the + UCLIBC_CTOR_DTOR option and just set those two arguments to NULL + glibc generally stores this function in libc/sysdeps/ARCH/elf/start.S - create these additional files in ARCH/bits/ @@ -38,13 +40,15 @@ you are hacking on. copy linux asm-ARCH/stat.h to bits/kernel_stat.h create syscalls.h based upon linux's unistd.h / glibc's sysdeps.h ... really - you just want to define the _syscall[0-6] macros + you just want to define the _syscall[0-6] macros. It is important that + these syscalls should be PIC safe (or you should provide a PIC and non-PIC + version) if you wish to properly support shared libraries. - at this point, you should have enough to generate a working HELLO WORLD static binary (see test/silly/*.c files) - if you want UCLIBC_CTOR_DTOR support, you will need to create crti.S and - crtn.S files which define function prologues/epilogues + crtn.S files which define function prologues/epilogues. - for a more stable static port, you will need to create these files (and update the Makefile.arch values accordingly) @@ -62,7 +66,7 @@ TODO: nptl / linuxthreads / linuxthreads.old === ldso sysdeps === ==================== - enable ldso/shared options in your extra/Configs/Config.ARCH file -- you'll need to create these files in ldso/ldso/ARCH/ +- you will need to create the following files in ldso/ldso/ARCH/ dl-debug.h dl-startup.h dl-syscalls.h dl-sysdep.h elfinterp.c resolve.S - dl-debug.h: define string versions of all the relocations of your arch in the |