linux 内核学习7-通过QEMU调试ARMV8的Linux内核
linux 内核学习7-通过QEMU调试ARMV8的Linux内核
1. 准备工作
$ sudo apt-get install gcc-aarch64-linux-gnu gcc-5-aarch64-linux-gnu
2. 切换GCC版本
默认的GCC版本是7.+的版本，现在要替换为5.+的版本
- 设置gcc-5的版本
sudo update-alternatives --install /usr/bin/aarch64-linux-gnu-gcc aarch64-linux-gnu-gcc /usr/bin/aarch64-linux-gnu-gcc-5 5
- 设置gcc-7的版本
sudo update-alternatives --install /usr/bin/aarch64-linux-gnu-gcc aarch64-linux-gnu-gcc /usr/bin/aarch64-linux-gnu-gcc-7 7
- 选择GCC-5的版本
$ sudo update-alternatives --config aarch64-linux-gnu-gcc
There are 2 choices for the alternative aarch64-linux-gnu-gcc (providing /usr/bin/aarch64-linux-gnu-gcc).
Selection Path Priority Status
------------------------------------------------------------
* 0 /usr/bin/aarch64-linux-gnu-gcc-7 7 auto mode
1 /usr/bin/aarch64-linux-gnu-gcc-5 5 manual mode
2 /usr/bin/aarch64-linux-gnu-gcc-7 7 manual mode
Press to keep the current choice[*], or type selection number: 1
update-alternatives: using /usr/bin/aarch64-linux-gnu-gcc-5 to provide /usr/bin/aarch64-linux-gnu-gcc (aarch64-linux-gnu-gcc) in manual mode
- 检查
aarch64-linux-gnu-gcc版本是否为gcc-5的版本
$ aarch64-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=aarch64-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/lib/gcc-cross/aarch64-linux-gnu/5/lto-wrapper
Target: aarch64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 5.5.0-12ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-5/README.Bugs --enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-5 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new --enable-gnu-unique-object --disable-libquadmath --enable-plugin --enable-default-pie --with-system-zlib --enable-multiarch --enable-fix-cortex-a53-843419 --disable-werror --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=aarch64-linux-gnu --program-prefix=aarch64-linux-gnu- --includedir=/usr/aarch64-linux-gnu/include
Thread model: posix
gcc version 5.5.0 20171010 (Ubuntu/Linaro 5.5.0-12ubuntu1)
3. 编译系统
参照之前的文章-linux 内核学习3-自己编译一个ARM Linux内核
这里相比于32位的ARM内核，只是一些参数不同，其他参数都是相同的
- 配置环境变量
$ export ARCH=arm64
$ export CROSS_COMPILE=aarch64-linux-gnu-8o
- 编译
cd linux-4.19.67
export ARCH=arm64
export CROSS_COMPILE=aarch64-linux-gnu-
make menuconfig
General setup --->
[*] Initial RAM filesystem and RAM disk (initramfs/initrd) support
(_install_arm64) Initramfs source file(s)
Boot options --->
() Default kernel command string (NEW)
Kernel Features --->
Page size (4KB) --->
Virtual address space size (48-bit) --->
修改内容
$ make -j2
- 启动虚拟机
qemu-system-aarch64 -machine virt -cpu cortex-a57 -machine type=virt -nographic -m 2048 -smp 2 -kernel arch/arm64/boot/Image --append "rdinit=/linuxrc console=ttyAMA0"
- 遇到的问题
- 问题1
缺少vexpress_config文件，这个我个人的做法是从arm/configs文件夹拷贝vexpress_defconfig到arm64/configs
- 问题2
$ make bzImage -j2 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
scripts/kconfig/conf --syncconfig Kconfig
make: *** No rule to make target 'bzImage'. Stop.
提示无法编译bzImage
这个时候通过make help发现并没有make bzImage命令
Cleaning targets:
clean - Remove most generated files but keep the config and
enough build support to build external modules
mrproper - Remove all generated files + config + various backup files
distclean - mrproper + remove editor backup and patch files
Configuration targets:
config - Update current config utilising a line-oriented program
nconfig - Update current config utilising a ncurses menu based program
menuconfig - Update current config utilising a menu based program
xconfig - Update current config utilising a Qt based front-end
gconfig - Update current config utilising a GTK+ based front-end
oldconfig - Update current config utilising a provided .config as base
localmodconfig - Update current config disabling modules not loaded
localyesconfig - Update current config converting local mods to core
defconfig - New config with default from ARCH supplied defconfig
savedefconfig - Save current config as ./defconfig (minimal config)
allnoconfig - New config where all options are answered with no
allyesconfig - New config where all options are accepted with yes
allmodconfig - New config selecting modules when possible
alldefconfig - New config with all symbols set to default
randconfig - New config with random answer to all options
listnewconfig - List new options
olddefconfig - Same as oldconfig but sets new symbols to their
default value without prompting
kvmconfig - Enable additional options for kvm guest kernel support
xenconfig - Enable additional options for xen dom0 and guest kernel support
tinyconfig - Configure the tiniest possible kernel
testconfig - Run Kconfig unit tests (requires python3 and pytest)
Other generic targets:
all - Build all targets marked with [*]
* vmlinux - Build the bare kernel
* modules - Build all modules
modules_install - Install all modules to INSTALL_MOD_PATH (default: /)
dir/ - Build all files in dir and below
dir/file.[ois] - Build specified target only
dir/file.ll - Build the LLVM assembly file
(requires compiler support for LLVM assembly generation)
dir/file.lst - Build specified mixed source/assembly target only
(requires a recent binutils and recent build (System.map))
dir/file.ko - Build module including final link
modules_prepare - Set up for building external modules
tags/TAGS - Generate tags file for editors
cscope - Generate cscope index
gtags - Generate GNU GLOBAL index
kernelrelease - Output the release version string (use with make -s)
kernelversion - Output the version stored in Makefile (use with make -s)
image_name - Output the image name (use with make -s)
headers_install - Install sanitised kernel headers to INSTALL_HDR_PATH
(default: ./usr)
Static analysers:
checkstack - Generate a list of stack hogs
namespacecheck - Name space analysis on compiled kernel
versioncheck - Sanity check on version.h usage
includecheck - Check for duplicate included header files
export_report - List the usages of all exported symbols
headers_check - Sanity check on exported headers
headerdep - Detect inclusion cycles in headers
coccicheck - Check with Coccinelle
Kernel selftest:
kselftest - Build and run kernel selftest (run as root)
Build, install, and boot kernel before
running kselftest on it
kselftest-clean - Remove all generated kselftest files
kselftest-merge - Merge all the config dependencies of kselftest to existing
.config.
Userspace tools targets:
use "make tools/help"
or "cd tools; make help"
Kernel packaging:
rpm-pkg - Build both source and binary RPM kernel packages
binrpm-pkg - Build only the binary kernel RPM package
deb-pkg - Build both source and binary deb kernel packages
bindeb-pkg - Build only the binary kernel deb package
snap-pkg - Build only the binary kernel snap package (will connect to external hosts)
tar-pkg - Build the kernel as an uncompressed tarball
targz-pkg - Build the kernel as a gzip compressed tarball
tarbz2-pkg - Build the kernel as a bzip2 compressed tarball
tarxz-pkg - Build the kernel as a xz compressed tarball
perf-tar-src-pkg - Build perf-4.19.67.tar source tarball
perf-targz-src-pkg - Build perf-4.19.67.tar.gz source tarball
perf-tarbz2-src-pkg - Build perf-4.19.67.tar.bz2 source tarball
perf-tarxz-src-pkg - Build perf-4.19.67.tar.xz source tarball
Documentation targets:
Linux kernel internal documentation in different formats from ReST:
htmldocs - HTML
latexdocs - LaTeX
pdfdocs - PDF
epubdocs - EPUB
xmldocs - XML
linkcheckdocs - check for broken external links (will connect to external hosts)
refcheckdocs - check for references to non-existing files under Documentation
cleandocs - clean all generated files
make SPHINXDIRS="s1 s2" [target] Generate only docs of folder s1, s2
valid values for SPHINXDIRS are: driver-api networking sound media core-api userspace-api gpu maintainer process input crypto doc-guide vm sh dev-tools filesystems kernel-hacking x86 admin-guide
make SPHINX_CONF={conf-file} [target] use *additional* sphinx-build
configuration. This is e.g. useful to build with nit-picking config.
Default location for the generated documents is Documentation/output
Architecture specific targets (arm64):
* Image.gz - Compressed kernel image (arch/arm64/boot/Image.gz)
Image - Uncompressed kernel image (arch/arm64/boot/Image)
* dtbs - Build device tree blobs for enabled boards
dtbs_install - Install dtbs to /boot/dtbs/4.19.67
install - Install uncompressed kernel
zinstall - Install compressed kernel
Install using (your) ~/bin/installkernel or
(distribution) /sbin/installkernel or
install to $(INSTALL_PATH) and run lilo
vexpress_defconfig - Build for vexpress
make V=0|1 [targets] 0 => quiet build (default), 1 => verbose build
make V=2 [targets] 2 => give reason for rebuild of target
make O=dir [targets] Locate all output files in "dir", including .config
make C=1 [targets] Check re-compiled c source with $CHECK (sparse by default)
make C=2 [targets] Force check of all c source with $CHECK
make RECORDMCOUNT_WARN=1 [targets] Warn about ignored mcount sections
make W=n [targets] Enable extra gcc checks, n=1,2,3 where
1: warnings which may be relevant and do not occur too often
2: warnings which occur quite often but may still be relevant
3: more obscure warnings, can most likely be ignored
Multiple levels can be combined with W=12 or W=123
Execute "make" or "make all" to build all targets marked with [*]
For further info see the ./README file
这里使用
$ make Image -j2 ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-
来解决