Re: 关于Linux下高版本内核编译低版本内核的问题

下面是FC5下编译2.4.20的例子，FC5有bug，中文命名文件会没有反映，建议用稳定的FC4，FC5内核貌似2.6.15还是18忘了。

1.准备2.4.20的源代码
$tar jxf linux-2.4.20.tar.bz2
$mv linux-2.4.20 linux
$cd linux
$make mrproper
$make config
$make dep
上面这些步骤都能顺利

通过
$make bzImage
一会就出现了如下的 错误

/usr/linux-2.4.20/include/linux/smp.h:29: error: conflicting types for 'smp_send_reschedule'
/usr/linux-2.4.20/include/asm/smp.h:42: error: previous declaration of 'smp_send_reschedule' was here In file included from /usr/linux-2.4.20/include/linux/unistd.h:9,from init/main.c:17:
/usr/linux-2.4.20/include/asm/unistd.h:375: warning: conflicting types for built-in function '_exit'

这是因为FC5下的GCC版本太新（gcc4.1）
建议使用 gcc 2.95或者gcc3.2进行编译（Dave Thompson）
在网上寻找了一会，发现其实FC5下可以安装一个pachage，就可以使用gcc3.2，同时不会影响当前的gcc4.1。
于是就在
ftp://rpmfind.net/linux/fedora/core/5/i386/os/Fedora/RPMS/compat-gcc-32-3.2.3-55.fc5.i386.rpm
里下载了一个
该包的大致描述为：The compatibility GNU Compiler Collection Fedora Core 5 for i386，马上进行安装
$rpm -ivh compat-gcc-32-3.2.3-55.fc5.i386.rpm
安装完成后在/usr/bin下多了一个gcc32
于是马上修改Makefile，把里面的CC修改为 gcc32，接着
$make bzImage

经过漫长的等待（不长，也就15分钟左右），结果等来的却是：

{standard input}: Assembler

messages:
{standard input}:936: Error: suffix or operands invalid for `mov'
{standard input}:937: Error: suffix or operands invalid for `mov'
{standard input}:1031: Error: suffix or operands invalid for `mov'
{standard input}:1032: Error: suffix or operands invalid for `mov'
{standard input}:1083: Error: suffix or operands invalid for `mov'
{standard input}:1084: Error: suffix or operands invalid for `mov'
{standard input}:1086: Error: suffix or operands invalid for `mov'
{standard input}:1098: Error: suffix or operands invalid for `mov'

结论：是FC5下的binutils的一个bug，
下载相应的补丁
http://www.kernel.org/pub/linux/devel/binutils/linux-2.6-seg-5.patch
在待编译的内核源码（本例为linux-2.4.20/）的根目录下进行patch操作：
$patch -p1
patching file arch/i386/kernel/process.c
Hunk #1 succeeded at 693 with fuzz 1 (offset 96 lines).
patching file arch/i386/kernel/vm86.c
Hunk #1 FAILED at 294.
1 out of 1 hunk FAILED -- saving

rejects to file arch/i386/kernel/vm86.c.rej
patching file arch/x86_64/kernel/process.c
Hunk #1 succeeded at 458 with fuzz

2 (offset 67 lines).
Hunk #2 succeeded at 443 with fuzz 2 (offset -14 lines).
Hunk #3 FAILED at 458.
Hunk #4 FAILED at 479.
2 out of 4 hunks FAILED -- saving rejects to file arch/x86_64/kernel/process.c.rej
patching file include/asm-

i386/system.h
Hunk #1 succeeded at 84 (offset 3 lines).
Hunk #2 FAILED at 96.
1 out of 2 hunks FAILED -- saving rejects to

file include/asm-i386/system.h.rej

$make bzImage
又是漫长的等待，出现如下错误
{standard input}: Assembler messages:
{standard input}:936: Error: suffix or operands invalid for `mov'
{standard input}:937: Error: suffix or operands invalid for `mov'
{standard input}:1031: Error: suffix or operands invalid for `mov'
{standard input}:1032: Error: suffix or operands invalid for `mov'
make[1]: *** [process.o] 错误 1
make[1]: Leaving directory `/usr/src/linux/arch/i386/kernel'
make: *** [_dir_arch/i386/kernel] 错误 2

是as的问题，再编辑
arch/i386/kernel/process.c
在579行，将
asm volatile("movl %%" #seg ",%0":"=m" (*(int *)&(value)))
改成
asm volatile("mov %%" #seg ",%0":"=m" (value))
执行
$make bzImage
一切正常
$make modules
$make modules_install
出现了如下的信息

cd /lib/modules/2.4.20; \
mkdir -p pcmcia; \
find kernel -path '*/pcmcia/*' -name '*.o' | xargs -i -r ln -sf ../{} pcmcia
if [ -r System.map ]; then /sbin/depmod -ae -F System.map 2.4.20; fi
Version requires old depmod, but couldn't run /sbin/depmod.old: No such file or directory
make: *** [_modinst_post] 错误 2

那就创建一个depmod.old的链接
$ln -s /sbin/depmod /sbin/depmod.old
$make modules_install
$mkinitrd -f -v /boot/initrd-2.4.20.img 2.4.20
一切正常，修改相应的

lino或者 grub，重新启动。



如果你不是用FC5，再遇到错误贴出来我给你看。。。。