BfuCLinux

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intro

i have borrowed my works bfin kit to get a stable uClinux image to use for our robotics program as well as future projects. as always i will try not to duplicate any info that can be found on the blackfin project site. if you wanna talk about it come to #blackfin on irc.freenode.net.

uClinux

i didn't have any luck with the default uClinux images so i decided to roll my own. the issues stemed from the fact that i was using an unsupported kit (BF537-EZKIT with a 1.0.1 rev blackfin). The blackfin is presently on rev 1.0.2 and the EZKIT is supported but is referred to as the STAMP because the boards are pretty much the same. As such i am using the bf537-stamp option in the configuration. The EZKIT has a lot more of the board populated (namely audio and other headers and USB-JTAG emulator that talks to VisualDSP++) but for the bf537 they are essentially the same kit (this is not true for the bf533 kits).

configs

after playing around for a few days i came up with a stable config for the bf537-ezkit (rev 1.0.2). this is by no means optimal and will face considerable changes in the weeks to come however you can build a stable image with this config if you are using the 2006R1-RC2 release. These do not seem to work with other releases.

• bf537-stable-apps-config: bf537-stable-apps-config
• bf537-stable-kernel-config: bf537-stable-kernel-config

this provides a fairly basic system with sash and a ramdisk.

issues

the biggest issues that i faced involved a Uboot decompression error and init not properly executing. because of the uboot issue i'm using the ELF image (linux rather than uImage) and downloading via tftp. I was using serial but the 10MB linux image took about an hour to download. the latter issue was mainly due to the kernel config (properly supporting MTD devices) and issues with Busybox and init (/bin/sh was not spawning).

i also had to remove all of the 'fancy' features from ls because that also caused a kernel panic. i will now slowly add and remove the features that i actually want in my linux image. these issues seemed to be related to the 1.0.1 version of the blackfin more than anything else. Do Not use the BF537 1.0.1 with linux - you will just bang your head against the wall needlessly.

note - my issues stemmed from using the bf537 v1.0.1 rather than the v1.0.2

gotcha - be careful to keep a backup of whatever you put in the romfs directory as these files are routinely deleted and recreated by make

**** Cleaning tree for old settings ****
rm -rf romfs; make clean > /dev/null 2>&1

inside the blackfin

/> cat /proc/cpuinfo
CPU:            ADSP-BF537 Rev. 0.1
MMU:            none
FPU:            none
Core Clock:     500000000 Hz
System Clock:   100000000 Hz
BogoMips:       995.32
Calibration:    497664000 loops
BOARD Name  :   Unknown
BOARD Memory:   64 MB
I-CACHE:        ON
D-CACHE:        ON (write-through)
I-CACHE Size:   16KB
D-CACHE Size:   32KB
I-CACHE Setup:  4 Sub-banks/4 Ways, 32 Lines/Way
D-CACHE Setup:  2 Super-banks/4 Sub-banks/2 Ways, 64 Lines/Way

1000 bogomips doesn't seem too bad. can't wait to really work this system out.

-- ChristopherPepe - 29 Jul 2006