[U-Boot-Users] Big thanks for a great piece of free software

Niklaus Giger niklaus.giger at member.fsf.org
Fri Feb 25 00:32:17 CET 2005


I would like to thank all developpers and contributors of the U-Boot for their 
great work.

Last weekend I started a personal project in my free time to port the boot 
loader to the custom PPC405GPr board. (Not a hardware bringup). Reading the 
README and getting acquainted with the requirements took me a couple of days. 
Configuring, checking the 40 or so of the most important registers of the 
PPC405. I lost some hours as i misconfigured my setup to use the internal 
UART1 instead of the UART0 and as I mistrusted my serial USB connection 
(which is not very reliable on my Powerbook G4). So finally I had to use a 
Linux server at work to compile u-Boot and my WindowsPC as a serial console 
to convince me, that I had commited a programming error. But now everythink 
works fine at home.

Compared to my hardware bringup 15 months ago using vxWorks I was very pleased 
with the following aspects, where I think U-Boot is superior to vxWorks:

- U-Boot uses the internal 4 KB of static RAM as its initial stack and 
- the configuration of the SDRAM via SPI is done in C-code and not assembler!
- nifty boot shell with if's
- boot shell with a help system
- nice info about the PHY (MII)
- using the rest of the SPI-EEPROM as a storage to the environment
- reading/writing the DCR registers
- With about 120 KB a lot smaller than the corresponding 220 kB of a WALNUT 
booteprom from WindRiver

I can only recomment U-boot as a boot eprom and I hope I will be able to 
convince our management to use a lot of more free software (e.g. Linux or 
eCos as kernels) for our future products.

It was a joy to bring up this board with free software and I will try to boot 
Linux and RTAI using the ELDK. But I have to read a lot.

Best regards

Niklaus Giger
Wieshoschet 6
CH-8753 Mollis
Tel. ++41 55 612 20 54 (privat)
Tel. ++41 55 618 64 68 (Geschäft)

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