开始GeekOS之旅的时候,一开始就碰到了小麻烦,在自己64位的Fedora上编译GeekOS的时候报如下错误:
geekos/lowlevel.o: could not read symbols: File in wrong format
断定是平台问题.再去官网看了下:GeekOS is a tiny operating system kernel for x86 PCs.
看了后就决定换i386系统了,装上后就发现很多需要配置,太麻烦,稍微思考片刻,记得以前在编译其它i386代码时,是可以跨平台的,编译时搜索lib32库不就行了嘛.研究了下GeekOS的Makefile.
GeekOS提供的Makefile中是有编译于X64的配置的.拿 project0的Makefile来说,在第97行(GeekOS-0.3.0) 把TARGECT_CC_PREFIX打开就可以了. 但是你的OS需要安装Cross-development的开发包.
不过没关系,还有个方法就是加编译选项 -m32 和 链接选项 -m elf_i386 这样会在编译时自动去找lib32.在GeekOS的 Makefile中第100,106,109行改成如下:
100 TARGET_CC := $(TARGET_CC_PREFIX)gcc -m32 101 102 # Host C compiler. This is used to compile programs to execute on 103 # the host platform, not the target (x86) platform. On x86/ELF 104 # systems, such as Linux and FreeBSD, it can generally be the same 105 # as the target C compiler. 106 HOST_CC := gcc -m32 107 108 # Target linker. GNU ld is probably to only one that will work. 109 TARGET_LD := $(TARGET_CC_PREFIX)ld -m elf_i386
然后改动后,你可能需要安装glibc的386版本,fedora安装如下:
yum -y install glibc-devel.i686
然后再进行编译就OK了:
cat geekos/fd_boot.bin geekos/setup.bin geekos/kernel.bin > fd.img
镜像文件成功生成.