Building LinuxBIOS: Difference between revisions

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== Warnings and Disclaimers ==
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[http://www.bolea.com/x2.htm 运动粘度]
[http://www.bolea.com/ 倾点凝点]
[http://www.zbgb.com/ 股骨头坏死]
[http://tejiajipiao.cn.35so.cn/ 特价机票]
[http://www.bjlxjy.com/ 集团电话]
[http://www.bhjj.net/ 北京家教]
[http://www.sj83.com/google.htm google排名]
[http://www.global-jipiao.cn/ 特价机票]
[http://www.beijingyizheng.com/zhongkongban/ 塑料周转箱]
[http://www.njjghg.com/user/jghg/index_cn.asp 偶联剂]
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'''These instructions are new and subject to change. No assurance is made that this won't permanently harm your hardware. If you don't understand any of these steps, please stop and ask for clarification on the mailing lists or in IRC. You have now been officially warned.'''
[http://www.jingeyuqi.com.cn/index.asp 婚庆公司]

[http://www.jingeyuqi.com.cn/index.asp 演出公司]
== Buildrom ==
[http://www.jingeyuqi.com.cn/index.asp 广告公司]

[http://www.jingeyuqi.com.cn/product.asp 公关公司]
During boot, LinuxBIOS loads a small payload that consists of a minimal kernel and an initramfs image. We refer to this payload as the "ROM image".
[http://www.jingeyuqi.com.cn/intro.asp 北京婚庆公司]
The ROM image is responsible for bringing up the system enough to try to load a full kernel from the NAND flash, a USB mass storage device, or the network.
[http://www.jingeyuqi.com.cn/yanchu.asp 北京演出公司]
Buildrom is a small set of build scripts that facilitiates building the bootloader and ROM image (including the kernel and all the different utilities and scripts that make
[http://www.jingeyuqi.com.cn/yewu.asp 礼仪庆典公司]
up the initramfs image). If you understand buildroot (from the uclibc team), then buildrom will look familiar - it is based on the same concept.
[http://www.jingeyuqi.com.cn/index.asp 文化传播有限公司]

[http://www.bj-huaao.com/ 机票]
Buildrom is a GNU Make based build system. Using a series of configuration files, the makefile will determine what packages need to be built. Each package is
[http://www.98689.net/ LED显示屏]
obtained from an upstream repository with wget and built locally on your machine. When all the packages have been built, the script pulls together all the binaries
[http://www.baida.org/ google排名]
for the ROM image, and combines them into a .ELF file which is then used as the payload to build a LinuxBIOS ROM.
[http://www.baida.org/google.html google左侧排名]

'''Update''' - buildrom now builds ROM images for the SPI flash by default. You don't need to change anything from the default configuration.

=== Getting buildrom ===

Buildrom is available from the OLPC GIT repository on [http://dev.laptop.org http://dev.laptop.org]. After installing git, run:

$ git clone git://dev.laptop.org/users/jcrouse/buildrom

This will make a copy of the tree in a folder called 'buildrom'. From time to time, you will want to make sure you are synced with the tree:
$ cd buildrom; git pull

=== Building the image ===

Buildrom requires the following tools on your development system to run:

* make
* gcc
* svn
* wget
* quilt
* perl

To build the default image, just type

$ make

You will notice that the system will start downloading packages from the web with wget, and compiling them. If you are behind a proxy, don't forget to set http_proxy
before starting.

$ export http_proxy=<proxyurl>:<proxyport>

Note that there is also one package (LinuxBIOS) that will be pulled down with SVN. If you have proxy worries, make sure your local SVN environment is correctly setup.

Buildrom already sets all the important flags and other settings to build the tools and libraries so they can be included into the ROM.
There are several configuration options you can play with once you are more familar with the system. Check ''Config.mk'' and read the comments.

=== Using the Image ===

When the system is done building, you will have three files in the deploy/ directory:

* bzImage - The minimal kernel that was built
* initrd - the gziped initramfs image
* olpc-payload.elf - ELF file that includes both the bzImage and the initrd. This is the payload that LinuxBIOS uses.

The most important deliverable is the 1MB ROM image:
* linuxbios.rom

== What Next? ==

* [[Flashing LinuxBIOS]]

* [[Recipes for buildrom and LinuxBIOS]]

* [[ROM Emulators for OLPC]]

* [[Building an SPI image for olpcflash]]

* [[Maintainer Notes]]

Revision as of 18:20, 10 December 2006

Warnings and Disclaimers

These instructions are new and subject to change. No assurance is made that this won't permanently harm your hardware. If you don't understand any of these steps, please stop and ask for clarification on the mailing lists or in IRC. You have now been officially warned.

Buildrom

During boot, LinuxBIOS loads a small payload that consists of a minimal kernel and an initramfs image. We refer to this payload as the "ROM image". The ROM image is responsible for bringing up the system enough to try to load a full kernel from the NAND flash, a USB mass storage device, or the network. Buildrom is a small set of build scripts that facilitiates building the bootloader and ROM image (including the kernel and all the different utilities and scripts that make up the initramfs image). If you understand buildroot (from the uclibc team), then buildrom will look familiar - it is based on the same concept.

Buildrom is a GNU Make based build system. Using a series of configuration files, the makefile will determine what packages need to be built. Each package is obtained from an upstream repository with wget and built locally on your machine. When all the packages have been built, the script pulls together all the binaries for the ROM image, and combines them into a .ELF file which is then used as the payload to build a LinuxBIOS ROM.

Update - buildrom now builds ROM images for the SPI flash by default. You don't need to change anything from the default configuration.

Getting buildrom

Buildrom is available from the OLPC GIT repository on http://dev.laptop.org. After installing git, run:

$ git clone git://dev.laptop.org/users/jcrouse/buildrom

This will make a copy of the tree in a folder called 'buildrom'. From time to time, you will want to make sure you are synced with the tree:

$ cd buildrom; git pull

Building the image

Buildrom requires the following tools on your development system to run:

  • make
  • gcc
  • svn
  • wget
  • quilt
  • perl

To build the default image, just type

 $ make

You will notice that the system will start downloading packages from the web with wget, and compiling them. If you are behind a proxy, don't forget to set http_proxy before starting.

 $ export http_proxy=<proxyurl>:<proxyport>

Note that there is also one package (LinuxBIOS) that will be pulled down with SVN. If you have proxy worries, make sure your local SVN environment is correctly setup.

Buildrom already sets all the important flags and other settings to build the tools and libraries so they can be included into the ROM. There are several configuration options you can play with once you are more familar with the system. Check Config.mk and read the comments.

Using the Image

When the system is done building, you will have three files in the deploy/ directory:

  • bzImage - The minimal kernel that was built
  • initrd - the gziped initramfs image
  • olpc-payload.elf - ELF file that includes both the bzImage and the initrd. This is the payload that LinuxBIOS uses.

The most important deliverable is the 1MB ROM image:

  • linuxbios.rom

What Next?