[U-Boot-Users] Big thanks for a great piece of free software
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
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.
Tel. ++41 55 612 20 54 (privat)
Tel. ++41 55 618 64 68 (Geschäft)
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