Kernel Build Instructions - Revision history

Piet at 22:17, 17 September 2009

2009-09-17T22:17:51Z

← Older revision		Revision as of 22:17, 17 September 2009
Line 32:		Line 32:
	* <code>Image.elf</code>		* <code>Image.elf</code>
	*: The build scripts always create this elf image. It contains a reset vector and doesn't require a boot loader.		*: The build scripts always create this elf image. It contains a reset vector and doesn't require a boot loader.
	* <code>~~Image~~.RedBoot</code>		* <code>zImage.RedBoot</code>
	*: This binary image is created for targets that support RedBoot as the boot loader.		*: This binary image is created for targets that support RedBoot as the boot loader.ls
			* <code>uImage</code>
			*: This binary image is created for targets that support U-Boot as the boot loader. This requires that you copy u-boot/tool/mkimage to somewhere in you search path before before building the kernel.

Marc: Add reference to Buildroot build instructions

2008-01-15T01:38:41Z

Add reference to Buildroot build instructions

← Older revision		Revision as of 01:38, 15 January 2008
Line 1:		Line 1:
			'''''Note:''' For a more complete example showing how to build a complete toolchain, root file system, and kernel, see [[Buildroot_Build_Instructions]].''

	Building a kernel for Xtensa is not different from any other architecture. It is a two-step process that requires to configure the kernel first before it can be built. The configuration step is initiated with <code>make config\|menuconfig\|xconfig</code> and allows to choose from various device drivers, file systems, and network and other kernel options. This results in the <code>.config</code> file describing the selected options. A simple <code>make</code> will then build the kernel image.		Building a kernel for Xtensa is not different from any other architecture. It is a two-step process that requires to configure the kernel first before it can be built. The configuration step is initiated with <code>make config\|menuconfig\|xconfig</code> and allows to choose from various device drivers, file systems, and network and other kernel options. This results in the <code>.config</code> file describing the selected options. A simple <code>make</code> will then build the kernel image.

Alain94040: /* Configure the Kernel */

2007-05-08T18:32:00Z

Configure the Kernel

← Older revision		Revision as of 18:32, 8 May 2007
Line 19:		Line 19:
	* <code>config</code> - Queries all available options (nobody should really use this way to configure the kernel, though).		* <code>config</code> - Queries all available options (nobody should really use this way to configure the kernel, though).
	* <code>menuconfig</code> - Presents the kernel options in an ASCII/vt100 compatible menu structure.		* <code>menuconfig</code> - Presents the kernel options in an ASCII/vt100 compatible menu structure.
	* <code>xconfig</code> - Similar to <code>menuconfig</code>, but uses tcl/tk to display the ~~meny~~ structure.		* <code>xconfig</code> - Similar to <code>menuconfig</code>, but uses tcl/tk to display the menu structure.

	Alternatively, you can choose to start with the default configuration for the targeted platform. The configuration files are located in <code>arch/xtensa/kernel/configs</code>. The name for the configuration file is usually the platform name followed by ''_defconfig'', for example ''iss_defconfig''. Simply issue <code>make</code> with the following options to create the <code>.config</code> file from the default configuration. You can then make modifications to select additional drivers or modify other options with one of the commands above.		Alternatively, you can choose to start with the default configuration for the targeted platform. The configuration files are located in <code>arch/xtensa/kernel/configs</code>. The name for the configuration file is usually the platform name followed by ''_defconfig'', for example ''iss_defconfig''. Simply issue <code>make</code> with the following options to create the <code>.config</code> file from the default configuration. You can then make modifications to select additional drivers or modify other options with one of the commands above.

Chris: New page: Building a kernel for Xtensa is not different from any other architecture. It is a two-step process that requires to configure the kernel first before it can be built. The configuration st...

2007-04-24T07:06:05Z

New page: Building a kernel for Xtensa is not different from any other architecture. It is a two-step process that requires to configure the kernel first before it can be built. The configuration st...

New page

Building a kernel for Xtensa is not different from any other architecture. It is a two-step process that requires to configure the kernel first before it can be built. The configuration step is initiated with <code>make config|menuconfig|xconfig</code> and allows to choose from various device drivers, file systems, and network and other kernel options. This results in the <code>.config</code> file describing the selected options. A simple <code>make</code> will then build the kernel image.

In case of cross-compilation, the Linux <code>make</code> scripts require two additional arguments:

* <code>ARCH=xtensa</code>
* <code>CROSS_COMPILE=''<prefix>''</code>

The <code>ARCH</code> argument instructs the <code>make</code> scripts to compile for a different architecture than the host system. <code>CROSS_COMPILE</code> defines the prefix for the compilation tools, for example <code>xtensa-unknown-linux-gnu-</code>.

The kernel makefile scripts allow additional optional arguments. This is just a short list of the more interesting ones:

* <code>O=''<build directory>''</code> - Build the kernel in the ''<build directory>'' instead of the current kernel source directory.
* <code>V=1</code> - Increase verbosity level to show the commands executed by the <code>make</code> scripts.

== Configure the Kernel ==

The first step requires to configure the kernel for the particular architecture and platform. Run <code>make ARCH=xtensa CROSS_COMPILE=''<prefix>''</code> with one of the following arguments. This will create the configuration file <code>.config</code> that is later used during the build process.

* <code>config</code> - Queries all available options (nobody should really use this way to configure the kernel, though).
* <code>menuconfig</code> - Presents the kernel options in an ASCII/vt100 compatible menu structure.
* <code>xconfig</code> - Similar to <code>menuconfig</code>, but uses tcl/tk to display the meny structure.

Alternatively, you can choose to start with the default configuration for the targeted platform. The configuration files are located in <code>arch/xtensa/kernel/configs</code>. The name for the configuration file is usually the platform name followed by ''_defconfig'', for example ''iss_defconfig''. Simply issue <code>make</code> with the following options to create the <code>.config</code> file from the default configuration. You can then make modifications to select additional drivers or modify other options with one of the commands above.

make ARCH=xtensa KBUILD_DEFCONFIG=''name''_defconfig defconfig

== Building the Kernel ==

After configuring the kernel, you can build the kernel image running <code>make</code>. The final kernel image is generated in <code>arch/xtensa/boot</code>. Depending on the platform and configuration options, one or more of the following images has been created:
* <code>Image.elf</code>
*: The build scripts always create this elf image. It contains a reset vector and doesn't require a boot loader.
* <code>Image.RedBoot</code>
*: This binary image is created for targets that support RedBoot as the boot loader.