1. Blackfin buildroot development
12/17/08
Blackfin buildroot development
Aaron Wu
ADI Open Source Solution

2. Agenda Getting started Blackfin Linux toolchain Blackfin Das-Uboot
Host machine environment
How to get help
Linux on bf609 quick start
Blackfin Linux toolchain
Download and install
Tollchain for 3 formats
Blackfin Das-Uboot
Download, config, and compile
Boot modes
Blackfin Linux kernel & App
Overview for Linux kernel/App running on Blackfin
NO-MMU App development on Blackfin Linux comparing to ARM or Intel Arch
Play with buildroot
Overview
Build an example target
Buildroot skeleton
Add a package in buildroot
Make patch for a package
work with git to submit patch
Work with buildroot & package upstream
Track tasks with sourceforge

3. Linux on Blackfin – Geting started
12/17/08
Linux on Blackfin – Geting started

4. Set up host machine
Q: I have the Ubuntu installed on my host PC, what’s the next?
A: Set up the host environment
Install required packages on host PC:
Install Blackfin Linux toolchain:
tar jxvf blackfin-toolchain-2013R1-RC1.i386.tar.bz2
tar jxvf blackfin-toolchain-elf-gcc R1-RC1.i386.tar.bz2
tar jxvf blackfin-toolchain-uclibc-default-2013R1-RC1.i386.tar.bz2
Q: Where do I get the source code and binary?
A: Download the release for u-boot, toolchain, and Blackfin Linux source code and binary from
Note: Be sure to use the matched version of u-boot, toolchain and Linux, mix different versions up lead to unknown problems, and use the latest release version.

5. How to get help – support model
Q: I have a problem, I need support
A: Asking questions on support forum: (English and Chinese)
blackfin
For toolchain
For Linux distribution
For U-boot
Before submitting your question:
Read the FAQ:
Search the forum for historical issues
When submitting your question, provide information:
1)detailed information for hardware environment and software version
2)log for the failure, along with your kernel and distribution configuration files
  3)steps description to reproduce your failure
Helpful document wiki: docs.blackfin.uclinux.org
mailist:

6. quick start Set up the hardware environment Set up the host machine
Switch to the appropriate boot mode
Connect the serial cable, eth cable, power supply.
Set up the host machine
Set up the terminal for Linux, minicom, N-1, HW flow control off
Set up the tftp server for Linux
1) sudo apt-get install tftp-hpa tftpd-hpa
2) sudo vi /etc/default/tftpd-hpa, set the TFTP_DIRECTOR to you own directory
3) sudo service tftpd-hpa restart
Run Default image
U-boot environment setting
Run Linux uImage
Update the bootloader
Transfer the image to board by Ethernet
bfin> tftp 0x u-boot.ldr
Flash to the serial Flash
bfin> sf probe 2 ?
bfin> sf erase 0x0 0x100000
bfin> sf write 0x x0 $SIZE
Initially Load the bootloader
bfin-uclinux-ldr -l u-boot.ldr

7. Linux on Blackfin – Toolchain
12/17/08
Linux on Blackfin – Toolchain

8. Installing toolchain Where to get
3 files needed, choose the right one according to your host pc hardware and software architectures
blackfin-toolchain-2013R1-RC1.i386.tar.bz2
blackfin-toolchain-elf-gcc R1-RC1.i386.tar.bz2
blackfin-toolchain-uclibc-default-2013R1-RC1.i386.tar.bz2
An example procedure
tar jxvf blackfin-toolchain-2013R1-RC1.i386.tar.bz2.
tar jxvf blackfin-toolchain-elf-gcc R1-RC1.i386.tar.bz2
tar jxvf blackfin-toolchain-uclibc-default-2013R1-RC1.i386.tar.bz2
cp -fr opt/uClinux /opt
Add to the PATH
export PATH=$PATH:/opt/uClinux/bfin-uclinux/bin:/opt/uClinux/bfin-linux- uclibc/bin:/opt/uClinux/bfin-elf/bin
Or edit the file ~/.bashrc to include the above line 8 8

9. Toolchain for 3 binary formats
FLAT bfin-uclinux-gcc
Binary Flat files known as BFLT, relatively simple and lightweight executable format based on the original a.out format. BFLT files are the default file format in embedded Linux, automatically link the application with the Linux run time libraries, usually for static library linking.
FDPIC ELF bfin-linux-uclibc-gcc
originally developed by Unix System Laboratories and has become the standard in file formats. The ELF standard has greater power and more flexibility than the BFLT format. However, they are more heavyweight, requiring more disk space and having a small run-time penalty, usually for dynamic library linking.
Bear metal bfin-elf-gcc
used for Non-OS applications, nothing to do with Linux, one example is code running on coreB of BF561/BF609.
FLAT and FDPIC can be selected from choosing different configuration file 9 9

10. Linux on Blackfin – U-boot
12/17/08
Linux on Blackfin – U-boot

11. U-boot – src download/compile
12/17/08
U-boot – src download/compile
Git clone and check out the source
git clone git://git.code.sf.net/p/adi-u-boot/code adi-u-boot-code
git checkout 2013R1
Configure and compile
vim include/configs/bf609-ezkit.h
make bf609-ezkit
Flash the u-boot
By gnICE
bfin-jtag
cable gnICE
detect
businit YOUR_BOARD
detectflash
flashmem 0x u-boot.ldr
By uart-utils:
bfin-uclinux-ldr -l u-boot.ldr
connect to minicom, the uart version of u-boot is running
use the runing u-boot to tftp load and flash bootloader 11 11

12. Bootmode selection 12 Support various booting methods How to select
12/17/08
Bootmode selection
Support various booting methods
Parallel NOR Flash
SPI NOR Flash
SD/MMC card (BF60x)
UART
How to select
H/W design, Input Pins BMODE[2:0] to select the booting mode
ROM code will check the BMODE Pins and choose the source accordingly
In board configuration file, define the CONFIG_BFIN_BOOT_MODE properly 12 12

13. 12/17/08
Linux on Blackfin

14. Linux running on Blackfin – Big Picture
12/17/08
Linux running on Blackfin – Big Picture
Userspace
Application
(Customer)
Opensource
Library
C Library
(uClibc)
Linux Kernel (supervisor)
Device Driver
Device Driver
Framework
B / Hardware

15. Application porting and development
API difference
Use vfork instead of fork, and _exit instead of exit
A fork produces a parent and child. Each have individual task control structures and each can be scheduled independently by the kernel. When we have an MMU the parent and child eventually occupy different physical memory spaces. The MMU maps different physical memory addresses to identical virtual memory addresses and copies the data from parent to child
Using thread APIs
Memory allocation
Because there is no virtual memory map, an uClinux application should try not to allocate and free dynamic memory continually, to avoid fragmenting memory. Application are recommended to malloc all memory at start up or manage allocation by itself, nedmalloc is one option for memory pool.
Fixed stack size
default stack size for FLAT binaries is 4k (0x1000) bytes
default stack size for FDPIC ELF binaries is 128k (0x20000) bytes
Stacksize can be modified with flthdr like “flthdr -s 8192 application”

16. 12/17/08
Play with Buildroot

17. Buildroot introduction
12/17/08
Buildroot introduction
Made up of many configure scripts, make files and directories, allows you to easily add configuration options, documentation, dependencies, and integrate into Makefiles
Tree overview
board/ — board specific kernel configuration files
boot/ — boot loader config scripts and make files; not used for blackfin
config/ — the buildroot default configuration for different boards
dl/ — the source tarballs that are downloaded during building process
docs/ — how to configure and customize buildroot
fs/ — config scripts and make files to build different kinds of root file system image.
linux/ — config scripts, make files to build Linux kernel
linux/linux-kernel/ — the Linux kernel source
linux/patch/ — Patches to apply to the proper version of Linux kernel source
output/ — All building output files are put under this folder
output/build/ — Contain binaries of all software packages
output/images/ — Contain file system images and kernel booting up images.
output/staging/ — locally installed (“staged”) target libraries; they may be linked with target applications later
output/target/ — the compiled root file system image
packages/ — config scripts and make files to download and build libraries and applications
testsuites/ — scripts for testing various boards/packages/kernels/etc...
scripts/ — misc buildroot compile helper scripts
target/ — vendor-specific configuration files and build instructions
toolchain/ — GNU toolchain and GDB config scripts and make files 17 17

18. Build a target 18 Build a target
12/17/08
Build a target
Build a target
git clone git://git.code.sf.net/p/adi-buildroot/code adi-buildroot-code
cd adi-buildroot-code
git checkout 2013R1
git submodule update –init
cd linux/linux-kernel/
cd ../../
cd testsuites/
make bf609-ezkit_defconfig
make
cp output/images/uImage /tftpboot/ 18 18

19. Buildroot skeleton 19 Configure buildroot and linux-kernel
12/17/08
Buildroot skeleton
Configure buildroot and linux-kernel
make menuconfig
make linux-menuconfig
Buildroot skeleton
configs/bf609-ezkit_defconfig
.config
Config.in
packages dl
output/build/
output/build/*/.stamp_*
Linux/linux-kernel 19 19

20. Add a package in buildroot
12/17/08
Add a package in buildroot
diff --git a/package/Config.in b/package/Config.in
--- a/package/Config.in
+++ b/package/Config.in
-714,6 +714,7 source "package/snowball-init/Config.in"
source "package/bfin-dma/Config.in"
+source "package/sport_test/Config.in"
source "package/bfin-canned-demos/Config.in"
diff --git a/package/sport_test/Config.in b/package/sport_test/Config.in
--- /dev/null
+++ b/package/sport_test/Config.in
-0,0 +1,4
+config BR2_PACKAGE_SPORT_TEST
+ bool "bfin common sport test"
+ help
+ Bfin common sport test suite
diff --git a/package/sport_test/sport_test.mk b/package/sport_test/sport_test.mk
+++ b/package/sport_test/sport_test.mk
…. more detail check the patch file 20 20

21. Make patch for buildroot package
12/17/08
Make patch for buildroot package
Get the original version of codege organization type
cp adi-buildroot-code/dl/alsa-utils tar.bz2 .
tar jxvf alsa-utils tar.bz2
Make a copy of the original code and make changes on it
cp alsa-utils alsa-utils _new
vim alsa-utils /alsactl/init_utils_run.c
Diff to make a code patch
diff –Nurp alsa-utils alsa-utils _new > alsa-utils.patch
Move the diff generated patch to buildroot package directoryzation type
cp alsa-utils.patch buildroot/package/multimedia/alsa-utils 21 21

22. Work with git 22 Frequently used git commandsackage organization type
12/17/08
Work with git
Frequently used git commandsackage organization type
git clone
git checkout
git branch
git pull
git commit
git reset --hard
Format and submit a patch
git add alsa-utils.patch
git commit –a –s
add the comment
git format patch -1
edit the patch to add comments
git send-
git push
git send- set up
exmple: 22 22

23. 23 Work with buildroot & package upstream Buildrootion type
12/17/08
Work with buildroot & package upstream
Buildrootion type
website:
subscribe to mailist:
Other packages
website: by google
mailist: by google
Submit patches to upstream
better to work on the git repository when possible, and send patches with git send-
submit patch to both buildroot and specific package mailist/maintainer. 23 23

24. 24 Use sourceforge to track the tickets
12/17/08
Use sourceforge to track the tickets 24 24