190-2255 Bluetechnix, 190-2255 Datasheet - Page 20

• Manufacturer Part Number: 190-2255
• Description: EMULATOR GNICE JTAG UCLINUX
• Manufacturer: Bluetechnix
• Series: gnICEr
• Type: In-Circuit Emulatorr

Specifications of 190-2255

• Contents: Emulation Module
• For Use With/related Products: Blackfin® Processors
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 190-2253; 190-2253

8 The U-Boot boot loader
In order to load and boot uClinux on the Blackfin, a boot loader is required. The Bluetechnix
project on the Blackfin uClinux web site contains pre‐compiled U‐Boot images for each Core
Module in the “Files” section (http://blackfin.uclinux.org/gf/project/bluetechnix/frs/).
The source code of U‐Boot is available on the Blackfin uClinux web site:
http://blackfin.uclinux.org/gf/project/u‐boot
The documentation Wiki (available at http://docs.blackfin.uclinux.org/) contains lot of
information about U‐Boot.
8.1 Flashing the U-Boot
If U‐Boot is not installed yet on your Core Module, you can either use a JTAG flash
programmer, the BLACKSheep software, or UART boot, to program U‐Boot into flash
memory. UART boot is supported by BF527, BF537, and BF548 processors only.
Table 8‐1 lists all Core Modules and the file type of U‐Boot that must be used for flash
programming.
Please refer to the “BLACKSheep Command Reference” (available on the Bluetechnix web
site, http://www.bluetechnix.at) for instructions how to program U‐Boot with BLACKSheep.
It is recommended to first program U‐Boot as application and to test it before replacing
BLACKSheep with U‐Boot, because if the U‐Boot does not work and you have already
removed the BLACKSheep, you would need a JTAG flash programmer.
After you have replaced BLACKSheep with U‐Boot, you have to change the boot mode of
those Core Modules that execute the u-boot.bin file. Please refer to the “Hardware User
Manual” (available on the Bluetechnix web site) of your Core Module for the appropriate DIP
switch settings.
8.2 U-Boot environment
The U‐Boot boot loader uses environment variables for configuration of network and boot
settings.
Blackfin uClinux User Guide
U‐Boot file
Module
Core
Note!
CM‐BF527
u‐boot.ldr
Do not use the “saveenv” command of U‐Boot if you programmed it as application
with BLACKSheep. This command saves the U‐Boot environment variables to flash
memory and may overwrite parts of BLACKSheep, making it unusable.
Table 8‐1: U‐Boot image types for Core Modules
CM‐BF533
u‐boot.bin
u‐boot.bin
BF537U
CM‐
maximum performance at minimum size
u‐boot.bin
BF537E
CM‐
u‐boot.bin
BF537
TCM‐
CM‐BF548
u‐boot.ldr
Tinyboards
CM‐BF561
u‐boot.ldr
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