BKM: starting a new BSP - Revision history

Tzanussi at 19:41, 31 March 2012

2012-03-31T19:41:30Z

← Older revision		Revision as of 19:41, 31 March 2012
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			Note: Though much of this page is still valid and can be useful in many cases, it should be noted that there are now tools that can help with the task of creating new BSPs and managing kernel patches and configuration settings for those BSPs, which you may want to consider first. Detailed documentation and walk-throughs using those tools are available at the following pages:

			[https://wiki.yoctoproject.org/wiki/Yocto_BSP_Tools_Documentation Yocto BSP Tools Documentation], [https://wiki.yoctoproject.org/wiki/Transcript:_Using_the_Yocto_BSP_tools_to_manage_kernel_patches_and_config_items Transcript: Using the Yocto BSP tools to manage kernel patches and config items], [https://wiki.yoctoproject.org/wiki/Transcript:_Using_the_Yocto_BSP_tools_to_create_a_qemu_BSP Transcript: Using the Yocto BSP tools to create a qemu BSP] and [https://wiki.yoctoproject.org/wiki/Transcript:_Using_the_Yocto_BSP_tools_to_create_a_meta-intel_BSP Transcript: Using the Yocto BSP tools to create a meta-intel BSP].

	This is a practical 'quick start' on creating a new BSP. For detailed background and instructions on how to to formally do this, please see the [http://www.yoctoproject.org/docs/1.1/bsp-guide/bsp-guide.html BSP Developer's Guide] and the [http://www.yoctoproject.org/docs/1.1/kernel-manual/kernel-manual.html Kernel Manual]. This document is essentially a pragmatic distillation of those documents but oriented toward the mechanics of quickly getting the initial BSP infrastructure in place for a minimally functional new BSP.		This is a practical 'quick start' on creating a new BSP. For detailed background and instructions on how to to formally do this, please see the [http://www.yoctoproject.org/docs/1.1/bsp-guide/bsp-guide.html BSP Developer's Guide] and the [http://www.yoctoproject.org/docs/1.1/kernel-manual/kernel-manual.html Kernel Manual]. This document is essentially a pragmatic distillation of those documents but oriented toward the mechanics of quickly getting the initial BSP infrastructure in place for a minimally functional new BSP.

Tzanussi: /* Pointing the build at a local kernel (using the meta-kernel-dev layer) */

2011-08-05T22:49:20Z

Pointing the build at a local kernel (using the meta-kernel-dev layer)

← Older revision		Revision as of 22:49, 5 August 2011
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	$ cd poky		$ cd poky
	$ mkdir poky-extras; cd poky-extras		$ mkdir poky-extras; cd poky-extras
			$ git init
	$ git remote add poky-extras git://git.yoctoproject.org/poky-extras.git		$ git remote add poky-extras git://git.yoctoproject.org/poky-extras.git
	$ git remote update		$ git remote update

Tzanussi: /* Creating a new kernel branch for the BSP */

2011-06-29T03:45:51Z

Creating a new kernel branch for the BSP

← Older revision		Revision as of 03:45, 29 June 2011
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	define KTYPE standard		define KTYPE standard
	define KARCH i386		define KARCH i386

	scc_leaf ktypes/standard crownbay		scc_leaf ktypes/standard crownbay

	include crownbay.scc		include crownbay.scc

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	define KTYPE standard		define KTYPE standard
	define KARCH i386		define KARCH i386

	scc_leaf ktypes/standard fishriver		scc_leaf ktypes/standard fishriver

	include fishriver.scc		include fishriver.scc

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	cfg/kernel-cache/bsp/fishriver$ mv crownbay.scc fishriver.scc		cfg/kernel-cache/bsp/fishriver$ mv crownbay.scc fishriver.scc
	cfg/kernel-cache/bsp/fishriver$ cat fishriver.scc		cfg/kernel-cache/bsp/fishriver$ cat fishriver.scc

	kconf hardware crownbay.cfg		kconf hardware crownbay.cfg
	kconf hardware eg20t.cfg		kconf hardware eg20t.cfg

	git merge yocto/emgd		git merge yocto/emgd

	include features/intel-e1xxxx/intel-e1xxxx.scc		include features/intel-e1xxxx/intel-e1xxxx.scc
	include features/drm-emgd/drm-emgd.scc		include features/drm-emgd/drm-emgd.scc
	include features/dmaengine/dmaengine.scc		include features/dmaengine/dmaengine.scc
	include features/serial/8250.scc		include features/serial/8250.scc

	include features/logbuf/size-normal.scc		include features/logbuf/size-normal.scc

	include features/latencytop/latencytop.scc		include features/latencytop/latencytop.scc
	include features/profiling/profiling.scc		include features/profiling/profiling.scc
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	CONFIG_NETDEVICES=y		CONFIG_NETDEVICES=y
	CONFIG_ATA=y		CONFIG_ATA=y

	# Hardware support for the Platform Controller Hub EG20T		# Hardware support for the Platform Controller Hub EG20T

	CONFIG_PCH_DMA=y		CONFIG_PCH_DMA=y
	CONFIG_PCH_UART_DMA=y		CONFIG_PCH_UART_DMA=y
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	$ git log remotes/origin/yocto/emgd		$ git log remotes/origin/yocto/emgd

	commit 2264cdc31a6e222fb65caad042505934e156b7ad		commit 2264cdc31a6e222fb65caad042505934e156b7ad
	Author: Tom Zanussi <tom.zanussi@intel.com>		Author: Tom Zanussi <tom.zanussi@intel.com>
	Date: Wed May 11 09:05:59 2011 -0500		Date: Wed May 11 09:05:59 2011 -0500

	emgd: backfix for 2.6.37		emgd: backfix for 2.6.37

	Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>		Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>

	commit fc264f1dfb3b17f0239e08ad7c3c0f98b09fd5c2		commit fc264f1dfb3b17f0239e08ad7c3c0f98b09fd5c2
	Author: Tom Zanussi <tom.zanussi@intel.com>		Author: Tom Zanussi <tom.zanussi@intel.com>
	Date: Fri May 6 22:50:20 2011 -0500		Date: Fri May 6 22:50:20 2011 -0500

	yocto/emgd: 2.6.39 fixes		yocto/emgd: 2.6.39 fixes

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	Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>		Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>

	commit 7946104c07ac52a7e5816d2156f9b6f8ed09dbfa		commit 7946104c07ac52a7e5816d2156f9b6f8ed09dbfa
	Author: Tom Zanussi <tom.zanussi@intel.com>		Author: Tom Zanussi <tom.zanussi@intel.com>
	Date: Tue May 3 16:56:56 2011 -0500		Date: Tue May 3 16:56:56 2011 -0500

	yocto/emgd: build fixups		yocto/emgd: build fixups

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	Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>		Signed-off-by: Tom Zanussi <tom.zanussi@intel.com>

	commit eab1e2634aece1f89cdc7b7b95364c54a532a2f3		commit eab1e2634aece1f89cdc7b7b95364c54a532a2f3
	Author: Tom Zanussi <tom.zanussi@intel.com>		Author: Tom Zanussi <tom.zanussi@intel.com>
	Date: Tue May 3 16:44:37 2011 -0500		Date: Tue May 3 16:44:37 2011 -0500

	yocto/emgd: emgd 1.61 driver		yocto/emgd: emgd 1.61 driver

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	$ cat meta/cfg/kernel-cache/features/drm-emgd/drm-emgd.cfg		$ cat meta/cfg/kernel-cache/features/drm-emgd/drm-emgd.cfg

	CONFIG_DRM=y		CONFIG_DRM=y
	CONFIG_DRM_EGD=m		CONFIG_DRM_EGD=m

Tzanussi: /* Pointing the build at a local kernel (using the meta-kernel-dev layer) */

2011-06-29T03:43:48Z

Pointing the build at a local kernel (using the meta-kernel-dev layer)

← Older revision		Revision as of 03:43, 29 June 2011
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	KSRC_linux_yocto ?= /home/trz/work/linux-yocto-2.6.37.git		KSRC_linux_yocto ?= /home/trz/work/linux-yocto-2.6.37.git

	KMACHINE_fishriver ?= "yocto/standard/fishriver"		KMACHINE_fishriver ?= "yocto/standard/fishriver"

Tzanussi: /* One-off options */

2011-06-29T03:43:07Z

One-off options

← Older revision		Revision as of 03:43, 29 June 2011
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	CONFIG_MATOM=y		CONFIG_MATOM=y
	CONFIG_PRINTK=y		CONFIG_PRINTK=y

	# Basic hardware support for the box - network, USB, PCI, sound		# Basic hardware support for the box - network, USB, PCI, sound
	CONFIG_NETDEVICES=y		CONFIG_NETDEVICES=y

	# Here's our new option, we just want to enable PRINTK_TIME, nothing more		# Here's our new option, we just want to enable PRINTK_TIME, nothing more
	CONFIG_PRINTK_TIME		CONFIG_PRINTK_TIME

Tzanussi: /* General-purpose options */

2011-06-29T03:42:49Z

General-purpose options

← Older revision		Revision as of 03:42, 29 June 2011
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	CONFIG_HPET_TIMER=y		CONFIG_HPET_TIMER=y
	CONFIG_HPET_EMULATE_RTC=y		CONFIG_HPET_EMULATE_RTC=y

	# enable /dev/hpet and allow it to be mmapped		# enable /dev/hpet and allow it to be mmapped
	CONFIG_HPET=y		CONFIG_HPET=y
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	The directory and two files taken together constitute the 'hpet' feature, which can be used by any BSP as such:		The directory and two files taken together constitute the 'hpet' feature, which can be used by any BSP as such:

	include features/hpet		include features/hpet/hpet.scc

	which results in the given config options appearing in the final kernel .config.		which results in the given config options appearing in the final kernel .config.

Tzanussi: /* Making kernel configuration changes and/or applying kernel patches */

2011-06-29T02:12:25Z

Making kernel configuration changes and/or applying kernel patches

← Older revision		Revision as of 02:12, 29 June 2011
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	SRCREV_machine_pn-linux-yocto_fishriver ?= "697d84759be192403a8a87ab269196c67a0c2c88"		SRCREV_machine_pn-linux-yocto_fishriver ?= "697d84759be192403a8a87ab269196c67a0c2c88"
	SRCREV_meta_pn-linux-yocto_fishriver ?= "f1dc3722d45cdcc92c84ebfecf4ce616d2efed26"		SRCREV_meta_pn-linux-yocto_fishriver ?= "f1dc3722d45cdcc92c84ebfecf4ce616d2efed26"

			=== Adding new options and/or changing kernel code ===

	==== Making kernel configuration changes and/or applying kernel patches ====		==== Making kernel configuration changes and/or applying kernel patches ====

Tzanussi: /* Options plus changes to the kernel code */

2011-06-29T02:10:31Z

Options plus changes to the kernel code

← Older revision		Revision as of 02:10, 29 June 2011
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	This case is exactly the same as the the previous option-only cases, except that in addition (or instead of), you check out the BSP's machine branch and make changes or apply patches, then commit the changes.		This case is exactly the same as the the previous option-only cases, except that in addition (or instead of), you check out the BSP's machine branch and make changes or apply patches, then commit the changes.

			Finally, in all cases, once you've made your changes and are happy with them, you'll want to follow the instructions in the 'Getting your changes into the official linux-yocto repo' section above in order to have your changes become part of the offical Yocto repositories.

Tzanussi: /* Setting/changing kernel config options */

2011-06-29T02:08:20Z

Setting/changing kernel config options

← Older revision		Revision as of 02:08, 29 June 2011
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	* one-off - specific to a given BSP		* one-off - specific to a given BSP
	* general-purpose - an option or grouping of options that would benefit multiple BSPs		* general-purpose - an option or grouping of options that would benefit multiple BSPs

			====== One-off options ======

	The one-off case is the simplest - in this case, you simply want to enable the option in the BSP and be done with it. For this type of option, you can just add the option to the BSP's top-level .cfg file e.g. in the case of fishriver, you'd add the option to the top-level meta/cfg/kernel-cache/bsp/fishriver/fishriver.cfg file:		The one-off case is the simplest - in this case, you simply want to enable the option in the BSP and be done with it. For this type of option, you can just add the option to the BSP's top-level .cfg file e.g. in the case of fishriver, you'd add the option to the top-level meta/cfg/kernel-cache/bsp/fishriver/fishriver.cfg file:
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	In this case, there's really nothing reusable about turning on timestamps for printk, so we commit this change to fishriver.cfg, rebuild (NOTE: unless you tell the build system to rebuild the kernel, it won't and you won't see the change if that doesn't happen - try bitbake yocto-linux -c cleanall) and when we reboot, we should see timestamps in our dmesg output.		In this case, there's really nothing reusable about turning on timestamps for printk, so we commit this change to fishriver.cfg, rebuild (NOTE: unless you tell the build system to rebuild the kernel, it won't and you won't see the change if that doesn't happen - try bitbake yocto-linux -c cleanall) and when we reboot, we should see timestamps in our dmesg output.

			====== General-purpose options ======

	The general-purpose case is a little more involved but not much. Take for example, turning on high-precision event timers. Doing this actually involves several config options and is likely to be something that many BSPs would like to do, so it's a perfect candidate for a new 'kernel feature' encapsulating the options.		The general-purpose case is a little more involved but not much. Take for example, turning on high-precision event timers. Doing this actually involves several config options and is likely to be something that many BSPs would like to do, so it's a perfect candidate for a new 'kernel feature' encapsulating the options.
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	Again, we need to commit this change to fishriver.cfg and rebuild in order to have the config options take effect.		Again, we need to commit this change to fishriver.cfg and rebuild in order to have the config options take effect.

			===== Options plus changes to the kernel code =====

			This case is exactly the same as the the previous option-only cases, except that in addition (or instead of), you check out the BSP's machine branch and make changes or apply patches, then commit the changes.

Tzanussi: /* Getting your changes into the official linux-yocto repo */

2011-06-29T02:03:32Z

Getting your changes into the official linux-yocto repo

← Older revision		Revision as of 02:03, 29 June 2011
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	In other words, in order for the changes you've made to actually be built into the kernel, the SRCREVs in the meta-fishriver/recipes-kernel/linux/linux-yocto_2.6.37.bbappend must contain the commit ids of the final commits on the BSP's machine branch and the repo's meta branch:		In other words, in order for the changes you've made to actually be built into the kernel, the SRCREVs in the meta-fishriver/recipes-kernel/linux/linux-yocto_2.6.37.bbappend must contain the commit ids of the final commits on the BSP's machine branch and the repo's meta branch:

	SRCREV_machine_pn-linux-yocto_fishriver ?= "697d84759be192403a8a87ab269196c67a0c2c88"		SRCREV_machine_pn-linux-yocto_fishriver ?= "697d84759be192403a8a87ab269196c67a0c2c88"
	SRCREV_meta_pn-linux-yocto_fishriver ?= "f1dc3722d45cdcc92c84ebfecf4ce616d2efed26"		SRCREV_meta_pn-linux-yocto_fishriver ?= "f1dc3722d45cdcc92c84ebfecf4ce616d2efed26"

	==== Making kernel configuration changes and/or applying kernel patches ====		==== Making kernel configuration changes and/or applying kernel patches ====