【问题】
折腾：
期间，交叉编译出错：CLi@PC-CLI-1 ~/develop/kernel/linux-2.6.19.1
$ make ARCH=arm CROSS_COMPILE=arm-xscale-linux-gnueabi- zImage
CHK include/linux/version.h
make[1]: `include/asm-arm/mach-types.h' is up to date.
CHK include/linux/utsrelease.h
HOSTCC scripts/basic/fixdep
scripts/basic/fixdep.c: In function ‘parse_config_file’:
scripts/basic/fixdep.c:242:4: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/fixdep.c: In function ‘parse_dep_file’:
scripts/basic/fixdep.c:319:4: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/fixdep.c: In function ‘traps’:
scripts/basic/fixdep.c:371:2: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
scripts/basic/fixdep.c:373:4: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing]
HOSTCC scripts/basic/docproc
scripts/basic/docproc.c: In function ‘find_export_symbols’:
scripts/basic/docproc.c:188:5: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c:191:5: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c:197:5: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c:200:5: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c: In function ‘singfunc’:
scripts/basic/docproc.c:267:17: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c: In function ‘parse_file’:
scripts/basic/docproc.c:300:6: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c:305:6: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c:310:6: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c:316:6: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/basic/docproc.c:319:6: warning: array subscript has type ‘char’ [-Wchar-subscripts]
HOSTCC scripts/mod/mk_elfconfig
MKELF scripts/mod/elfconfig.h
HOSTCC scripts/mod/file2alias.o
In file included from scripts/mod/file2alias.c:13:0:
scripts/mod/modpost.h:36:0: warning: "ELF_R_SYM" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/file2alias.c:13:
/usr/include/sys/elf_generic.h:81:0: note: this is the location of the previous definition
In file included from scripts/mod/file2alias.c:13:0:
scripts/mod/modpost.h:37:0: warning: "ELF_R_TYPE" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/file2alias.c:13:
/usr/include/sys/elf_generic.h:82:0: note: this is the location of the previous definition
scripts/mod/file2alias.c: In function ‘do_of_entry’:
scripts/mod/file2alias.c:365:9: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/mod/file2alias.c: In function ‘do_vio_entry’:
scripts/mod/file2alias.c:381:3: warning: array subscript has type ‘char’ [-Wchar-subscripts]
HOSTCC scripts/mod/modpost.o
In file included from scripts/mod/modpost.c:15:0:
scripts/mod/modpost.h:36:0: warning: "ELF_R_SYM" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/modpost.c:15:
/usr/include/sys/elf_generic.h:81:0: note: this is the location of the previous definition
In file included from scripts/mod/modpost.c:15:0:
scripts/mod/modpost.h:37:0: warning: "ELF_R_TYPE" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/modpost.c:15:
/usr/include/sys/elf_generic.h:82:0: note: this is the location of the previous definition
HOSTCC scripts/mod/sumversion.o
In file included from scripts/mod/sumversion.c:10:0:
scripts/mod/modpost.h:36:0: warning: "ELF_R_SYM" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/sumversion.c:10:
/usr/include/sys/elf_generic.h:81:0: note: this is the location of the previous definition
In file included from scripts/mod/sumversion.c:10:0:
scripts/mod/modpost.h:37:0: warning: "ELF_R_TYPE" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/sumversion.c:10:
/usr/include/sys/elf_generic.h:82:0: note: this is the location of the previous definition
scripts/mod/sumversion.c:12:26: fatal error: linux/limits.h: No such file or directory
compilation terminated.
make[2]: *** [scripts/mod/sumversion.o] Error 1
make[1]: *** [scripts/mod] Error 2
make: *** [scripts] Error 2
CLi@PC-CLI-1 ~/develop/kernel/linux-2.6.19.1
$
如图：
即：scripts/mod/sumversion.c:12:26: fatal error: linux/limits.h: No such file or directory
【解决过程】
1.搜：
cygwin sumversion.c linux/limits.h: No such file or directory
找到：
其是Linux系统，所以安装1. kernel-headers
2. kernel-devel
后，就解决问题了。对于我此处没用。
2.参考：
去看了下：
linux-2.6.19.1\scripts\mod\sumversion.c
是：#include
3.突然想起来了，之前的折腾：
所以去先看看，当前的PATH中，是否包含对应的，此处Cygwin中的交叉编译器其下对应的那些路径，结果是的确没有：CLi@PC-CLI-1 ~/develop/kernel/linux-2.6.19.1
$ echo $PATH
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/bin:/opt/crosstool-ng/bin:/home/CLi/develop/crosstool-ng/x-tools/armxscalecurl/bin:/usr/local/bin:/usr/bin:/cygdrive/d/tmp/dev_install_root/Python27_x64:/cygdrive/d/tmp/dev_install_root/Python27_x64/Lib/site-packages/PyQt4:/cygdrive/d/tmp/dev_install_root/Perl64/site/bin:/cygdrive/d/tmp/dev_install_root/Perl64/bin:/cygdrive/c/Program Files/Common Files/Microsoft Shared/Windows Live:/cygdrive/c/Program Files (x86)/Common Files/Microsoft Shared/Windows Live:/cygdrive/c/Windows/system32:/cygdrive/c/Windows:/cygdrive/c/Windows/System32/Wbem:/cygdrive/c/Windows/System32/WindowsPowerShell/v1.0:/cygdrive/c/Program Files (x86)/Microsoft SQL Server/100/Tools/Binn:/cygdrive/c/Program Files/Microsoft SQL Server/100/Tools/Binn:/cygdrive/c/Program Files/Microsoft SQL Server/100/DTS/Binn:/cygdrive/d/tmp/WordPress/mysql/mysql-5.5.18/MySQL/MySQL Server 5.5/bin:/cygdrive/d/tmp/WordPress/DevRoot/MySQL/MySQL Server 5.5/bin:/cygdrive/d/tmp/WordPress/DevRoot/php-5.3.6-Win32-VC9-x64:/cygdrive/d/tmp/WordPress/DevRoot/php-5.3.6-Win32-VC9-x64/ext:/cygdrive/d/tmp/WordPress/DevRoot/Python27:/cygdrive/c/Program Files (x86)/Common Files/Acronis/SnapAPI:/cygdrive/c/Program Files (x86)/Windows Live/Shared:/cygdrive/c/Program Files/Java/jdk1.7.0_11/bin:/home/CLi/develop/docbook/tools/fop/lib:/home/CLi/develop/docbook/tools/fop:/cygdrive/d/DevInstallRoot/FF/DD_IDE_1.1.2/TOK/BIN:/cygdrive/d/DevInstallRoot/FF/DD_IDE_1.2.0/TOK/BIN:/cygdrive/d/DevRoot/EmbeddedDevelop/trunk/Research/CLI/FF/FBK/develop/tools/develop-tools:/cygdrive/d/tmp/WordPress/DevRoot/Python27/Scripts:/cygdrive/d/tmp/dev_install_root/PostgreSQL/8.3/bin:/cygdrive/d/tmp/dev_install_root/ant/apache-ant-1.8.4/bin:/cygdrive/c/Program Files/nodejs:/cygdrive/c/Program Files/Microsoft/Web Platform Installer:/cygdrive/c/Program Files/TortoiseSVN/bin:/cygdrive/d/DevRoot/IndustrialMobileAutomation/HandheldDataSetter/ANTLR/batchFile:/cygdrive/c/Program Files (x86)/QuickTime/QTSystem:/cygdrive/d/tmp/tmp_dev_root/android/adt-bundle-windows/sdk/platform-tools:/cygdrive/d/tmp/dev_install_root/Tesseract-OCR:/cygdrive/d/tmp/dev_install_root/jython2.5.3/bin:/cygdrive/d/devinstallroot/gnuarm/bin:/cygdrive/d/tmp/dev_install_root/HTML Help Workshop:/cygdrive/c/Users/CLi/AppData/Roaming/npm:/usr/lib/lapack
3.所以，想办法，把对应的，此处的交叉编译器其下的
sysroot/usr/include
和
sysroot/usr/include/linux
加到此处include路径，或者是PATH中去。
但是加之前，先去确认一下，交叉编译器其下，是否有linux/limits.h:：
结果是有的：CLi@PC-CLI-1 ~/develop/kernel/linux-2.6.19.1
$ find /home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi -name limits.h
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/arm-xscale-linux-gnueabi/include/c++/4.6.0/tr1/limits.h
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/arm-xscale-linux-gnueabi/sysroot/usr/include/limits.h
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/arm-xscale-linux-gnueabi/sysroot/usr/include/linux/limits.h
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/lib/gcc/arm-xscale-linux-gnueabi/4.6.0/include-fixed/limits.h
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/lib/gcc/arm-xscale-linux-gnueabi/4.6.0/install-tools/include/limits.h
4.再去把对应的路径：
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/arm-xscale-linux-gnueabi/sysroot/usr/include
和
/home/CLi/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/arm-xscale-linux-gnueabi/sysroot/usr/include/linux
加到PATH中。
即修改当前自己的.bashrc，加到PATH中，再source一下使得生效。
然后发现，其实，我此处的，另外的文件夹：
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17
下，才是我的交叉编译器的正则安装的路径，其下也有对应的limits.h文件：CLi@PC-CLI-1 ~/develop/kernel/linux-2.6.19.1
$ find /opt/
crosstool-ng/ gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/ gcc-tools/
CLi@PC-CLI-1 ~/develop/kernel/linux-2.6.19.1
$ find /opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/ -name limits.h
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/gcc-first/lib/gcc/arm-xscale-linux-gnu/4.0.4/include/limits.h
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/gcc-first/lib/gcc/arm-xscale-linux-gnu/4.0.4/install-tools/include/limits.h
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/lib/gcc/arm-xscale-linux-gnu/4.0.4/include/limits.h
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/lib/gcc/arm-xscale-linux-gnu/4.0.4/install-tools/include/limits.h
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/sysroot-arm-xscale-linux-gnu/usr/include/asm/limits.h
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/sysroot-arm-xscale-linux-gnu/usr/include/limits.h
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/sysroot-arm-xscale-linux-gnu/usr/include/linux/limits.h
即路径：
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/sysroot-arm-xscale-linux-gnu/usr/include
和
/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/sysroot-arm-xscale-linux-gnu/usr/include/linux
所以，现在只是添加这两个路径：#PATH=$HOME/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/bin:/opt/crosstool-ng/bin:$HOME/develop/crosstool-ng/x-tools/armxscalecurl/bin:$PATH
PATH=$HOME/develop/crosstool-ng/x-tools/arm-xscale-linux-gnueabi/bin:/opt/crosstool-ng/bin:$HOME/develop/crosstool-ng/x-tools/armxscalecurl/bin:$PATH:/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/sysroot-arm-xscale-linux-gnu/usr/include:/opt/gcc-4.0.4-glibc-2.3.6-kernel-2.6.17/sysroot-arm-xscale-linux-gnu/usr/include/linux
然后使其生效：CLi@PC-CLI-1 ~/develop/kernel/linux-2.6.19.1
$ source ~/.bashrc
重新编译试试，结果错误依旧：HOSTCC scripts/mod/sumversion.o
In file included from scripts/mod/sumversion.c:10:0:
scripts/mod/modpost.h:36:0: warning: "ELF_R_SYM" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/sumversion.c:10:
/usr/include/sys/elf_generic.h:81:0: note: this is the location of the previous definition
In file included from scripts/mod/sumversion.c:10:0:
scripts/mod/modpost.h:37:0: warning: "ELF_R_TYPE" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/sumversion.c:10:
/usr/include/sys/elf_generic.h:82:0: note: this is the location of the previous definition
scripts/mod/sumversion.c:12:26: fatal error: linux/limits.h: No such file or directory
compilation terminated.
make[2]: *** [scripts/mod/sumversion.o] Error 1
make[1]: *** [scripts/mod] Error 2
make: *** [scripts] Error 2
5.关闭cygwin，重新打开再试试，结果还是同样错误。
所以，接着只能去想办法，把对应的路径，添加到makefile的include中去。
但是没到怎么添加。。。
6.参考：
去把对应的
linux-2.6.19.1\scripts\mod\sumversion.c
中的：#include
改为：//#include
#include
然后再试试，结果就可以了：HOSTCC scripts/mod/modpost.o
In file included from scripts/mod/modpost.c:15:0:
scripts/mod/modpost.h:36:0: warning: "ELF_R_SYM" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/modpost.c:15:
/usr/include/sys/elf_generic.h:81:0: note: this is the location of the previous definition
In file included from scripts/mod/modpost.c:15:0:
scripts/mod/modpost.h:37:0: warning: "ELF_R_TYPE" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/modpost.c:15:
/usr/include/sys/elf_generic.h:82:0: note: this is the location of the previous definition
HOSTCC scripts/mod/sumversion.o
In file included from scripts/mod/sumversion.c:10:0:
scripts/mod/modpost.h:36:0: warning: "ELF_R_SYM" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/sumversion.c:10:
/usr/include/sys/elf_generic.h:81:0: note: this is the location of the previous definition
In file included from scripts/mod/sumversion.c:10:0:
scripts/mod/modpost.h:37:0: warning: "ELF_R_TYPE" redefined [enabled by default]
In file included from /usr/include/machine/elf.h:45:0,
from /usr/include/elf.h:37,
from scripts/mod/modpost.h:10,
from scripts/mod/sumversion.c:10:
/usr/include/sys/elf_generic.h:82:0: note: this is the location of the previous definition
scripts/mod/sumversion.c: In function ‘parse_file’:
scripts/mod/sumversion.c:275:3: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/mod/sumversion.c: In function ‘parse_source_files’:
scripts/mod/sumversion.c:350:24: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/mod/sumversion.c: In function ‘strip_rcs_crap’:
scripts/mod/sumversion.c:477:2: warning: array subscript has type ‘char’ [-Wchar-subscripts]
scripts/mod/sumversion.c:484:2: warning: array subscript has type ‘char’ [-Wchar-subscripts]
HOSTLD scripts/mod/modpost
如图：
【总结】
此处，当在Cygwin下交叉编译Linux时，在make zImage时出现：scripts/mod/sumversion.c:12:26: fatal error: linux/limits.h: No such file or directory
的错误
原因是：
linux-2.6.19.1\scripts\mod\sumversion.c
中的：#include
在Linux下可以正常找到的，但是在Cygwin下，找不到。
解决办法是：
把：
linux-2.6.19.1\scripts\mod\sumversion.c
中的：#include
改为：//#include
#include
即可。