On 06/15/2012 11:42 PM, Graeme Russ wrote:
Hi Stephen,
On 06/07/2012 03:45 PM, Stephen Warren wrote:
The Raspberry Pi model B uses the BCM2835 SoC, has 256MB of RAM, contains an SMSC 9512 USB LAN/Hub chip, and various IO connectors. For more details, see http://www.raspberrypi.org/.
Signed-off-by: Stephen Warren swarren@wwwdotorg.org
Now I really can't wait for my Raspberry Pi to turn up (due on 25 June)
Looking forward to trying this out - any hints / traps for young players?
Mostly U-Boot on RPi works like it would anywhere else. The few things to watch out for are:
a) Pick the correct toolchain to build with. For my branch, I assumed everyone was building for armhf/hardfp these days, and so from the tools repo:
https://github.com/raspberrypi/tools.git
I picked the toolchain in the x86-linux64-cross-arm-linux-hardfp sub-directory, and adjusted the U-Boot Makefiles to suite options required for that toolchain.
However, Oleksandr's U-Boot branch appears to rely upon the armel/softfp toolchain in the linux-x86 sub-directory.
b) You need to appropriate stuff in config.txt on the SD card - I apparently have:
device_tree=kernel.dtb device_tree_address=0x100 kernel_address=0x8000 disable_commandline_tags=1
and I store U-Boot in kernel.img.
(although I think the DT-related values are irrelevant when I'm booting U-Boot instead of a kernel)
You will of course need a 3.3v serial->something (USB or true RS232) adapter hooked up to GPIO header pins 6/8/10 for the console, since there's no video output support in U-Boot yet (although I suppose we could add USB keyboard support soon...)
Oh, and you'll probably want to update the binary firmware images on your SD card to the latest from: https://github.com/raspberrypi/firmware.git
The following email from Oleksandr will be interesting too: http://lists.infradead.org/pipermail/linux-rpi-kernel/2012-June/000060.html
Of course, this is all if you specifically want to use U-Boot. The default boot process already works completely, without involving U-Boot, but of course doesn't support e.g. network booting.