Nn embedded linux notes - Revision history

Ted: /* ↑ ↓ Extra Notes on QEMU */

2018-07-26T19:50:13Z

↑ ↓ Extra Notes on QEMU

Ted: /* ↑ ↓ kernel - specific configuration build results */

2018-07-26T19:49:47Z

↑ ↓ kernel - specific configuration build results

Ted: /* ↑ ↓ kernel - specific configuration build results */

2018-07-26T19:48:54Z

↑ ↓ kernel - specific configuration build results

Ted at 15:43, 22 January 2018

2018-01-22T15:43:46Z

Show changes

Ted: /* ↑ ↓ Buildroot */

2018-01-22T15:39:15Z

↑ ↓ Buildroot

Ted: /* ↑ ↓ Buildroot manual sections */

2018-01-19T22:01:42Z

↑ ↓ Buildroot manual sections

Ted: /* ↑ ↓ Buildroot manual sections */

2018-01-19T21:51:45Z

↑ ↓ Buildroot manual sections

Ted: /* ↑ ↓ Buildroot manual sections */

2018-01-19T21:51:25Z

↑ ↓ Buildroot manual sections

Ted: /* ↑ ↓ Buildroot manual sections */

2018-01-19T21:50:53Z

↑ ↓ Buildroot manual sections

Ted: /* ↑ ↓ Buildroot */

2018-01-19T21:50:31Z

↑ ↓ Buildroot

@@ Line 1,446: / Line 1,446: @@
 <pre>
-$ qemu-system-arm -M versatilepb -cpu arm1176 -m 256 -serial stdio -kernel /var/local/raspberrypi/qemu-rpi-kernel/kernel-qemu-4.4.34-jessiez -dtb /var/local/raspberrypi/linux/arch/arm/boot/dts/bcm2709-rpi-2-b.dtb -append "root=/dev/sda2 rootfstype=ext4 rw init=/bin/bash console=ttyAMA0" -drive format=raw,file=/home/veris/Downloads/raspberrypi/2017-08-16-raspbian-stretch-lite.img
+$ qemu-system-arm -M versatilepb -cpu arm1176 -m 256 -serial stdio -kernel /var/local/raspberrypi/qemu-rpi-kernel/kernel-qemu-4.4.34-jessiez -dtb /var/local/raspberrypi/linux/arch/arm/boot/dts/bcm2709-rpi-2-b.dtb -append "root=/dev/sda2 rootfstype=ext4 rw init=/bin/bash console=ttyAMA0" -drive format=raw,file=/home/${USER}/Downloads/raspberrypi/2017-08-16-raspbian-stretch-lite.img
 audio: Could not init `oss' audio driver

@@ Line 1,284: / Line 1,284: @@
 user	68m30.589s
 sys	5m9.499s
-veris@alta-spare-6:/var/local/raspberrypi/rpi-linux$ exit
 exit
 Script done, file is z--kernel-config-using-bcm2709-defconfig--try-2.txt
-veris@alta-spare-6:/var/local/raspberrypi/rpi-linux$
 </pre>

@@ Line 1,263: / Line 1,263: @@
 user	21m5.491s
 sys	1m21.729s
-veris@alta-spare-6:/var/local/raspberrypi/linux$
 </pre>

← Older revision		Revision as of 15:39, 22 January 2018
Line 1,298:		Line 1,298:

	[https://buildroot.org The Buildroot Project] is a many-years standing build system project targeted at embedded Linux system development. Per [https://buildroot.org/downloads/manual/manual.html Buildroot's documentation] this project shares much of the functionality and capacity of project and toolset known as Yocto, which is also a software project build management system. Buildroot however [https://buildroot.org/downloads/manual/manual.html#_cross_compilation_toolchain does not support Yocto-generated toolchains], apparently because to quote Buildroot's manual those toolchains contain non- tool chain parts beyond a given compiler, binutils and C and C++ libraries.		[https://buildroot.org The Buildroot Project] is a many-years standing build system project targeted at embedded Linux system development. Per [https://buildroot.org/downloads/manual/manual.html Buildroot's documentation] this project shares much of the functionality and capacity of project and toolset known as Yocto, which is also a software project build management system. Buildroot however [https://buildroot.org/downloads/manual/manual.html#_cross_compilation_toolchain does not support Yocto-generated toolchains], apparently because to quote Buildroot's manual those toolchains contain non- tool chain parts beyond a given compiler, binutils and C and C++ libraries.
		+
		+	Before reading far in these notes it is good to know a couple of important design scope matter about the Buildroot scripts and project. From chapter 10 of the Buildroot stable manual as of 2018 January:
		+
		+
		+	<b>
		+	* Buildroot is not designed to create systems with compilers and toolchains on them
		+	* Buildroot is not a [Linux] distribution generator
		+	</b>
		+
		+
		+	These points appear in the Frequently Asked Questions section of Buildroot's manual, and nearly all the things which Buildroot is not come out of the small-memory, small hardware resource nature of the embedded systems which Buildroot developers in general work to support. This said, Buildroot is still a highly useful and configurable tool -- set of scripts and more -- for building small, networked and functional Linux systems.
		+
		+	The same chapter 10 of the manual lists some alternative tools and projects to Buildroot, which include in their scope the adding of toolchains to target systems, systems being boot-loader, kernel, rootfs compiled and configured for a target board or hardware. Some of these alternate tools include [https://www.yoctoproject.org/ Yocto] and [https://www.yoctoproject.org/ Openembedded].
		+
		+

	An early search for ways to build a kernel and root filesystem led to [https://medicineyeh.wordpress.com/2016/03/29/buildup-your-arm-image-for-qemu/ Medicine Yeh's tutorial], but following his build steps did not yield any kernel which booted in QEMU. There are other buildroot projects available on-line and in the public domain, including a [https://github.com/gamaral/rpi-buildroot buildroot Rpi project by Guillermo Amaral] and a [http://www.jumpnowtek.com/rpi/Raspberry-Pi-Systems-with-Buildroot.html buildroot project involving Qt5 support] by Jumpnow Technologies LLC.		An early search for ways to build a kernel and root filesystem led to [https://medicineyeh.wordpress.com/2016/03/29/buildup-your-arm-image-for-qemu/ Medicine Yeh's tutorial], but following his build steps did not yield any kernel which booted in QEMU. There are other buildroot projects available on-line and in the public domain, including a [https://github.com/gamaral/rpi-buildroot buildroot Rpi project by Guillermo Amaral] and a [http://www.jumpnowtek.com/rpi/Raspberry-Pi-Systems-with-Buildroot.html buildroot project involving Qt5 support] by Jumpnow Technologies LLC.

@@ Line 1,321: / Line 1,321: @@
 [https://buildroot.org/downloads/manual/manual.html#full-rebuild 8.2] &nbsp;Full rebuilds, when and how to do them<br />
 [https://buildroot.org/downloads/manual/manual.html#_offline_builds 8.4] &nbsp;Building off-line<br />
 .8 Graphing package dependencies<br />
 .9 Graphing build duration<br />
 .10 Graphing file system size contribution of packages<br />

@@ Line 1,313: / Line 1,313: @@
 - 2018-01-19 FRI -
 Buildroot manual is long, and an important section to remember and return to is titled "[https://buildroot.org/downloads/manual/manual.html#make-tips Make Tips]".  This is section 8 in the stable manual published at [https://buildroot.org Buildroot dot org].  In particular this section talks about how to invoke `make` on a Buildroot project when major attributes such as target platform architecture change.  This manual section worth noting and revisiting.
@@ Line 1,323: / Line 1,322: @@
 [https://buildroot.org/downloads/manual/manual.html#_offline_builds 8.4] &nbsp;Building off-line<br />
 [https://buildroot.org/downloads/manual/manual.html#_advanced_usage &nbsp;8.12.5 package-specific make targets<br />
+.8 Graphing package dependencies<br />