Barebox

The Barebox bootloader was started in 2007 as an attempt to work around the limitations that U-Boot shows through its age. Originally dubbed U-Boot v2, it now has a different name because its design goals are different and it has it's own community in the meantime.

Barebox now supports arm, powerpc, mips, nios2, blackfin, x86 and a Linux userspace port called "sandbox".

Features:


 * Devices/Drivers Model
 * ata
 * eeprom
 * I2c
 * nand
 * nor
 * net
 * mfd
 * MMC
 * serial
 * SPI
 * USB
 * Host
 * Devices
 * Framebuffer
 * Filesystem
 * Posix Interface
 * Hush
 * password
 * DFU
 * Menu

= Build and configuration =

On contrary of U-Boot, Barebox uses Kbuild for the build and Kconfig for the configuration.

For the environment, a file system is used so you will not have to clobber any config.h file.



Barebox

U-Boot-v2 Presentation from CELF Embedded Linux Conference Europe Grenoble, 2009-10-16 (pdf)

Booting Linux Fast & Fancy (pdf)

= Sandbox =

One of the great thinks with barebox is the sandbox.

Basically you can develop and debug generic feature on your host:

1) compile it

for other arch than x86 or ppc you need to use the next branch or the mainline

As I just recently fix the support for all host

ARCH=sandbox make sandbox_defconfig

ARCH=sandbox make

now just start it

# ./barebox barebox 2011.10.0-00119-gad62fdb-dirty (Oct 15 2011 - 11:38:46) Board: sandbox Malloc space: 0x7f679f24b010 -> 0x7f679fa4b010 (size 8 MB) Open /dev/env0 No such file or directory no valid environment found on /dev/env0. Using default environment running /env/bin/init... barebox:/ barebox:/ ls -al /dev/ ls: invalid option -- a   cr 18446744073709551615 zero crw---      8249 defaultenv crw--- 4294967295 mem crw---      2198 fd0 barebox:/ devinfo devices: ` hostfile0 ` console0 ` cs0 ` ramfs0 ` devfs0 ` mem0 ` 0x00000000-0x00002038: /dev/defaultenv ` mem1 ` 0x00000000-0xfffffffe: /dev/mem ` tap0 ` eth0 drivers: console ramfs devfs tap mem cramfs hostfile barebox:/ barebox:/ help . - alias for source ? - alias for help [ - alias for test addpart - adds a partition table to a device boot_config - Boot Menu boot_menu - Boot Menu cat - concatenate file(s) cd - change working directory clear - clear screen cp - copy files crc32 - crc32 checksum calculation delpart - delete partition(s) devinfo - Show information about devices and drivers. dhcp - invoke dhcp client to obtain ip/boot params echo - echo args to console edit - Usage: (s)edit ethact - set current ethernet device exit - exit script export - export environment variables false - do nothing, unsuccessfully go - start application at address or file help - print online help linux_exec - Execute a command on the host loadenv - Load environment from ENVFS into DIRECTORY (default: /dev/env0 -> /env). login - login ls - list a file or directory md - memory display md5sum - md5 checksum calculation memcmp - memory compare memcpy - memory copy meminfo - print info about memory usage memset - memory fill menu - Menu Management mkdir - make directories mount - Mount a filesystem of a given type to a mountpoint or list mounted filesystems. mw - memory write (fill) passwd - passwd ping - ping printenv - Print value of one or all environment variables. pwd - print working directory readline - prompt for user input reset - Perform RESET of the CPU rm - remove files rmdir - remove directorie(s) saveenv - save environment to persistent storage sedit - alias for edit sh - run shell script sha1sum - sha1 checksum calculation sha224sum - sha224 checksum calculation sha256sum - sha256 checksum calculation sleep - delay execution for n seconds source - execute shell script in current shell environment test - minimal test like /bin/sh tftp - Load file using tftp protocol time - measure execution time of a command timeout - wait for a specified timeout true - do nothing, successfully umount - umount a filesystem version - print monitor version barebox:/

= Menu =

It's on ather great feature

Add Menu Framework

Introduce a menu framework that allow us to create list menu to simplify barebox and make it more user-frendly

This kind of menu is very usefull when you do not have a keyboard or a serial console attached to your board to allow you to interract with barebox

For the develloper part, The framework introduce two API

1) C that allow you to create menu, submenu, entry and complex menu action

2) Command that allow you as the C API to create menu, submenu, entry and complex menu action but this time the actions will be store in a function and then be evaluated and excecuted at runtime.

barebox:/ help menu Usage: menu [OPTION]... Manage Menu -m menu -l list -s show Advanced -e menu entry -a add -r remove -S select How to Show menu (-A auto select delay) (-d auto select description) menu -s -m [-A delay] [-d auto_display] List menu menu -l Add a menu menu -a -m -d Remove a menu menu -r -m Add an entry (-R for do no exit the menu after executing the command) (-b for box style 1 for selected) (and optional -c for the command to run when we change the state) menu -e -a -m -c [-R] [-b 0|1] -d Add a submenu entry (-R is not needed) (-b for box style 1 for selected) (and -c is not needed) menu -e -a -m -u submenu -d [-b 0|1] Remove an entry menu -e -r -m -n Select an entry menu -m -S -n List menu menu -e -l [menu] Menu example menu -a -m boot -d "Boot Menu" menu -e -a -m boot -c boot -d "Boot" menu -e -a -m boot -c reset -d "Reset" menu -s -m boot

An example

menu -a -m boot -d "Welcome on Barebox Boot Sequence" menu -e -a -m boot -c boot -d "  1: linux_2_6_36" menu -e -a -m boot -c boot -d "  2: linux_2_6_39" menu -e -a -m boot -c boot -d "  3: linux_3_0_0" menu -e -a -m boot -c boot -d "  4: installer" menu -e -a -m boot -c clear -d "  5: shell" menu -e -a -m boot -c reset -d "  6: reset" menu -s -m boot

The screen is clear and show

Welcome on Barebox Boot Sequence 1: linux_2_6_36 2: linux_2_6_39 3: linux_3_0_0 4: installer 5: shell 6: reset Auto Select in 1