Nn embedded linux notes
^ RaspberryPi Kernel Compilation
- 2017-11-25 SAT - These notes are of first efforts to cross-compile Linux kernel and device tree blob, on Intel i386/i686 host system, for target ARM system specifically RaspberryPi 2 dev board. As of 2017-DEC-09 Saturday, four or five custom kernel configurations with rpi target chosen / in mind have failed, for reasons such as "enermation or pound define value not an integer" and "alignment type of variable x not available [on target processor]". Ted noting that the Linux kernel stable release with all its options and supported target hardware platforms and peripherals is heavyweight, not by default configured to be small or simple as possible. Now also looking into Tiny Kernel wiki page and home page of Tiny Core Linux.
Here are instructions for compiling and for cross-compiling a Linux kernel for RaspberryPi target system:
Here are limited instructions on how to configure the Linux kernel for RaspberryPi target systems:
Back in 2017 February this year, February 24th just after Embedded Linux Conference, looks like Ted stepped through some of the instructions at this Raspberry Pi dot org documentation page. Ted noting there are two directories on compiling host in /mnt with this timestamp:
ted@localhost:/mnt$ ls -l make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig total 44 drwxr-xr-x 2 root root 4096 Oct 24 2016 dvd-rom drwxr-xr-x 2 root root 4096 Feb 24 2017 ext4 drwxr-xr-x 2 root root 4096 Feb 24 2017 fat32 . . .
When issuing the cross-compile command that task seemed to complete quickly, giving the following messages which total less than two hundred lines:
ted@rangari:~/projects/raspberrypi/linux$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- bcm2709_defconfig # # configuration written to .config # ted@rangari:~/projects/raspberrypi/linux$ make -j 2 ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage modules dtbs scripts/kconfig/conf --silentoldconfig Kconfig CHK include/config/kernel.release CHK include/generated/uapi/linux/version.h CHK include/generated/utsrelease.h HOSTCC scripts/dtc/dtc.o HOSTCC scripts/dtc/flattree.o HOSTCC scripts/dtc/fstree.o HOSTCC scripts/dtc/data.o HOSTCC scripts/dtc/livetree.o HOSTCC scripts/dtc/treesource.o HOSTCC scripts/dtc/srcpos.o make[1]: 'include/generated/mach-types.h' is up to date. CHK include/generated/timeconst.h CHK include/generated/bounds.h CHK include/generated/asm-offsets.h CALL scripts/checksyscalls.sh HOSTCC scripts/dtc/checks.o make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig HOSTCC scripts/dtc/util.o HOSTCC scripts/dtc/dtc-lexer.lex.o HOSTCC scripts/dtc/dtc-parser.tab.o HOSTLD scripts/dtc/dtc HOSTCC scripts/genksyms/genksyms.o HOSTCC scripts/genksyms/parse.tab.o HOSTCC scripts/mod/mk_elfconfig HOSTCC scripts/genksyms/lex.lex.o MKELF scripts/mod/elfconfig.hhttps://www.raspberrypi.org/forums/viewtopic.php?f=66&t=178806 HOSTCC scripts/mod/modpost.o HOSTLD scripts/genksyms/genksyms HOSTCC scripts/kallsyms HOSTCC scripts/mod/file2alias.o HOSTCC scripts/pnmtologo HOSTCC scripts/conmakehash make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig HOSTCC scripts/mod/sumversion.o HOSTCC scripts/recordmcount HOSTLD scripts/mod/modpost HOSTCC scripts/sortextable HOSTCC usr/gen_init_cpio CHK include/generated/compile.h GEN usr/initramfs_data.cpio.gz HOSTCC arch/arm/vdso/vdsomunge AS usr/initramfs_data.o LD usr/built-in.o MUNGE arch/arm/vdso/vdso.so.dbg OBJCOPY arch/arm/vdso/vdso.so AS arch/arm/vdso/vdso.o LD arch/arm/vdso/built-in.o GZIP kernel/config_data.gz make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig CHK kernel/config_data.h HOSTCC lib/gen_crc32table HOSTCC lib/raid6/mktables TABLE lib/raid6/tables.c CC [M] lib/raid6/tables.o LD [M] lib/raid6/raid6_pq.o GEN lib/crc32table.h CC lib/crc32.o LD lib/built-in.o LOGO drivers/video/logo/logo_linux_clut224.c LOGO drivers/video/logo/logo_linux_mono.c LOGO drivers/video/logo/logo_superh_mono.c make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig LOGO drivers/video/logo/logo_superh_vga16.c make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig LOGO drivers/video/logo/logo_linux_vga16.c LOGO drivers/video/logo/logo_blackfin_vga16.c LOGO drivers/video/logo/clut_vga16.c LOGO drivers/video/logo/logo_spe_clut224.c LOGO drivers/video/logo/logo_mac_clut224.c LOGO drivers/video/logo/logo_superh_clut224.c LOGO drivers/video/logo/logo_sun_clut224.c LOGO drivers/video/logo/logo_parisc_clut224.c LOGO drivers/video/logo/logo_blackfin_clut224.c LOGO drivers/video/logo/logo_dec_clut224.c LOGO drivers/video/logo/logo_m32r_clut224.c LOGO drivers/video/logo/logo_sgi_clut224.c CC drivers/video/logo/logo_linux_clut224.o LD drivers/video/logo/built-in.o LD drivers/video/built-in.o make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig LD drivers/built-in.o LINK vmlinux LD vmlinux.o MODPOST vmlinux.o GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o LD init/built-in.o KSYM .tmp_kallsyms1.o KSYM .tmp_kallsyms2.o LD vmlinux SORTEX vmlinux SYSMAP System.map OBJCOPY arch/arm/boot/Image Building modules, stage 2. Kernel: arch/arm/boot/Image is ready Kernel: arch/arm/boot/Image is ready GZIP arch/arm/boot/compressed/piggy.gzip AS arch/arm/boot/compressed/piggy.gzip.o LD arch/arm/boot/compressed/vmlinux OBJCOPY arch/arm/boot/zImage Kernel: arch/arm/boot/zImage is ready MODPOST 1540 modules LD [M] lib/raid6/raid6_pq.ko ted@rangari:~/projects/raspberrypi/linux$
At this point it looks like we may have enough to attempt the qemu invocation which was partially working off site west side, since couple days ago we were missing what appeared to be only the kernel when invoking qemu on build box rangari . . .
So we can launch Raspbian for the RaspberryPi 2 board, using a kernel we've built on an i386 architecture host server, using the default bcmp_2907 (mis-spelled) kernel config file. But we can't fully compile a kernel for an ARM / Rpi target architecture when we make any kernel configuration changes via `make menuconfig`. The script which successfully starts our qemu-system-arm version 2.10.0 is:
#!/bin/bash qemu-system-arm -kernel ./kernel-qemu-4.4.34-jessie -cpu arm1176 -m 256 -M versatilepb -serial stdio -append "root=/dev/sda2 rootfstype=ext4 rw" -hda ./2017-09-07-raspbian-stretch-lite.img -redir tcp:5022::22 -no-reboot exit 0
Right now this script is located along side several already compiled, ARM-targeted kernels which Ted believes are from the git available cross-compile Rpi project by one 'dhruvvyas90' . . . Dhruvvyas90 qemu-rpi-kernel.
ted@localhost:/var/local/ted/projects/raspberrypi/qemu_vms$ ls 2017-09-07-raspbian-stretch-lite.img kernel-qemu-4.1.7-jessie kernel-qemu-4.4.21-jessie README.md kernel-qemu-3.10.25-wheezy kernel-qemu-4.4.12-jessie kernel-qemu-4.4.26-jessie start-qemu.sh kernel-qemu-4.1.13-jessie kernel-qemu-4.4.13-jessie kernel-qemu-4.4.34-jessie tools ted@localhost:/var/local/ted/projects/raspberrypi/qemu_vms$
- Summary rpi kernel compilations -
As of 2017 Dec 2 we can using QEMU 2.10.0 boot and use Raspbian image and kernel from Raspberry Pi on-line store. We can also substitute alternate kernel in call to QEMU system emulator, a kernel from . . .
^ edit point - custom Rpi-targeted kernel config issues
- 2017-11-30 -
In file included from ./include/uapi/linux/stddef.h:1:0,
from ./include/linux/stddef.h:4,
from ./include/uapi/linux/posix_types.h:4,
from ./include/uapi/linux/types.h:13,
from ./include/linux/types.h:5,
from fs/xfs/xfs_linux.h:21,
from fs/xfs/xfs.h:32,
from fs/xfs/xfs_super.c:19:
In function ‘xfs_check_ondisk_structs’,
inlined from ‘init_xfs_fs’ at fs/xfs/xfs_super.c:1974:2:
./include/linux/compiler.h:518:38: error: call to ‘__compiletime_assert_119’ declared with attribute error: XFS: sizeof(xfs_dir2_sf_entry_t) is wrong, expected 3
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
^
./include/linux/compiler.h:501:4: note: in definition of macro ‘__compiletime_assert’
prefix ## suffix(); \
^
./include/linux/compiler.h:518:2: note: in expansion of macro ‘_compiletime_assert’
_compiletime_assert(condition, msg, __compiletime_assert_, __LINE__)
^
./include/linux/bug.h:54:37: note: in expansion of macro ‘compiletime_assert’
#define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
^
fs/xfs/xfs_ondisk.h:22:2: note: in expansion of macro ‘BUILD_BUG_ON_MSG’
BUILD_BUG_ON_MSG(sizeof(structname) != (size), "XFS: sizeof(" \
^
fs/xfs/xfs_ondisk.h:119:2: note: in expansion of macro ‘XFS_CHECK_STRUCT_SIZE’
XFS_CHECK_STRUCT_SIZE(xfs_dir2_sf_entry_t, 3);
^
scripts/Makefile.build:293: recipe for target 'fs/xfs/xfs_super.o' failed
make[2]: *** [fs/xfs/xfs_super.o] Error 1
scripts/Makefile.build:544: recipe for target 'fs/xfs' failed
make[1]: *** [fs/xfs] Error 2
Makefile:991: recipe for target 'fs' failed
make: *** [fs] Error 2
real 17m33.542s
user 16m10.988s
sys 0m53.000s
Ok as of 2017-12-08 and a few days ago Ted realizing that the `make menuconfig` type call to configure a Linux kernel for a RaspberryPi/Arm target architecture must be of the form:
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- menuconfig
Now again calling the version of this command with options to compile kernel, device tree binary, and modules:
$ make ARCH=arm CROSS_COMPILE=arm-linux-gnueabihf- zImage modules dtbs
^ edit point - further references for kernel configuration wrt RaspberryPi target
Ted found these references in the README.md file of QEMU Rpi Tools project. Local directory is qemu-rpi-kernel/. Invoking `git status .` shows this to be a git repository. Invoking `git remote -v` shows this repository to be a clone of:
ted@localhost:~/projects/qemu/qemu-rpi-kernel$ git remote -v origin https://github.com/dhruvvyas90/qemu-rpi-kernel.git (fetch) origin https://github.com/dhruvvyas90/qemu-rpi-kernel.git (push) ted@localhost:~/projects/qemu/qemu-rpi-kernel$ #
In the READ.md file the Rpi kernel project author who doesn't identify him or herself lists the following four references together, and there are a couple more refs beyond these mentioned near the end of READ.md:
https://web.archive.org/web/20131210001638/http://xecdesign.com/compiling-a-kernel/ https://web.archive.org/web/20131209235952/http://xecdesign.com/compiling-qemu/ https://web.archive.org/web/20131210001407/http://xecdesign.com/working-with-qemu/ https://web.archive.org/web/20131210001526/http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/
^ Rpi kernel configuration further references
- https://www.raspberrypi.org/forums/viewtopic.php?t=125085&p=839033 . . . shows use of `dpkg-query -l` to find kernel version details on Linux system.
^ general kernel configuration and compile reference
- 2017-12-05 - Ted adding section on general articles, some non-Rpi articles and reference materials which explain how to configure a kernel and then how to invoke the build process and point `make` to the new custom configuration file. This so far not clear from the instructions at Raspberry Pi's articles https://www.raspberrypi.org/documentation/linux/kernel/building.md and https://www.raspberrypi.org/documentation/linux/kernel/configuring.md. These references found at Google via search phrase "invoking make after custom kernel configuration":
^ Buildroot
Per Medicine Yeh's tutorial setting out to compile and use buildroot project, to create Linux based root file system to run under QEMU. Mid-way messages from `make` call on buildroot project downloaded from git repository:
/usr/bin/install -m 0644 support/misc/target-dir-warning.txt /var/local/ted/projects-on-slash-var/buildroot/buildroot/output/target/THIS_IS_NOT_YOUR_ROOT_FILESYSTEM >>> skeleton-init-sysv Extracting >>> skeleton-init-sysv Patching >>> skeleton-init-sysv Configuring >>> skeleton-init-sysv Building >>> skeleton-init-sysv Installing to target rsync -a --ignore-times --exclude .svn --exclude .git --exclude .hg --exclude .bzr --exclude CVS --chmod=u=rwX,go=rX --exclude .empty --exclude '*~' package/skeleton-init-sysv//skeleton/ /var/local/ted/projects-on-slash-var/buildroot/buildroot/output/target/ >>> skeleton Extracting >>> skeleton Patching >>> skeleton Configuring >>> skeleton Building >>> skeleton Installing to target >>> linux-headers 4.14.4 Downloading --2017-12-09 23:11:28-- https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.14.4.tar.xz Resolving cdn.kernel.org (cdn.kernel.org)... 151.101.53.176, 2a04:4e42:d::432 Connecting to cdn.kernel.org (cdn.kernel.org)|151.101.53.176|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 100784788 (96M) [application/x-xz] Saving to: ‘/var/local/ted/projects-on-slash-var/buildroot/buildroot/output/build/.linux-4.14.4.tar.xz.VsSH6c/output’
Tail message from `make` on buildroot project:
chmod a+x /var/local/ted/projects-on-slash-var/buildroot/buildroot/output/build/buildroot-fs/fakeroot.fs rm -f /var/local/ted/projects-on-slash-var/buildroot/buildroot/output/target/THIS_IS_NOT_YOUR_ROOT_FILESYSTEM PATH="/var/local/ted/projects-on-slash-var/buildroot/buildroot/output/host/bin:/var/local/ted/projects-on-slash-var/buildroot/buildroot/output/host/sbin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin:/sbin:/usr/sbin:/opt/cross/bin:/opt/cross/x-tools/arm-unknown-linux-gnueabi/bin:/home/ted/bin:/usr/local/mysql/bin:/usr/lib/xscreensaver:/etc/init.d:/var/opt/sam-ba_cdc_cdc_linux" /var/local/ted/projects-on-slash-var/buildroot/buildroot/output/host/bin/fakeroot -- /var/local/ted/projects-on-slash-var/buildroot/buildroot/output/build/buildroot-fs/fakeroot.fs rootdir=/var/local/ted/projects-on-slash-var/buildroot/buildroot/output/target table='/var/local/ted/projects-on-slash-var/buildroot/buildroot/output/build/buildroot-fs/device_table.txt' /usr/bin/install -m 0644 support/misc/target-dir-warning.txt /var/local/ted/projects-on-slash-var/buildroot/buildroot/output/target/THIS_IS_NOT_YOUR_ROOT_FILESYSTEM real 48m56.055s user 53m27.352s sys 4m47.896s ted@rangari:/var/local/ted/projects/buildroot/buildroot$
