On Sat, Jun 1, 2013 at 12:19 AM, <[email protected]> wrote:
> Since it has u-boot installed and that the mapping of the flash is given
> does one know if one could build a Plan9 kernel, write it (via
> u-boot) to the flash and be able to boot?
>
It's quite possible. I even have it working. :-)
A couple of months ago I submitted a patch to the U-Boot mainline to add
formal support for Plan 9 kernels. It has since been accepted. At the same
time I also submitted a patch to Geoff which has been gathering dust to add
uImage support to 5l (patch/arm-uboot) - a requirement to exist nicely with
the loader. The exynos5 port that I am working on (Arndale Board, Samsung
Chromebook) relies on this exclusively.
If you are familiar with setting up a BSP for U-Boot, it's fairly
straightforward to boot a Plan 9 kernel from either a filesystem (ie. FAT,
ext2, etc.) or via TFTP. I tend to use TFTP while testing new kernels,
though longer lived kernels will likely end up sitting in a FAT - I haven't
quite decided yet.
Since you seem to be keen console spew, this is what a booted Arndale looks
like with the above patches:
U-Boot 2013.01.-rc1-00002-g67fd7e7-dirty (May 10 2013 - 23:58:01) for
ARNDALE5250
CPU: Exynos5250@1000MHz
Board: for ARNDALE5250
I2C: ready
DRAM: 2 GiB
WARNING: Caches not enabled
Checking Boot Mode ... SDMMC
MMC: EXYNOS DWMMC: 0, EXYNOS DWMMC: 1, EXYNOS DWMMC: 2
In: serial
Out: serial
Err: serial
Net: No ethernet found.
(Re)start USB...
USB0: USB EHCI 1.00
scanning bus 0 for devices... 4 USB Device(s) found
scanning usb for storage devices... 0 Storage Device(s) found
scanning usb for ethernet devices... 1 Ethernet Device(s) found
Hit any key to stop autoboot: 0
Waiting for Ethernet connection... done.
Using asx0 device
TFTP from server 10.0.0.8; our IP address is 10.0.0.10
Filename '/sys/src/9/exynos/9arndale'.
Load address: 0x42000000
Loading: #################################################################
###############################################
done
Bytes transferred = 1510728 (170d48 hex)
## Booting kernel from Legacy Image at 42000000 ...
Image Name: 9arndale
Image Type: ARM Plan 9 Kernel Image (uncompressed)
Data Size: 1510664 Bytes = 1.4 MiB
Load Address: b1000000
Entry Point: b1000000
Verifying Checksum ... OK
Loading Kernel Image ... OK
OK
## Transferring control to Plan 9 (at address b1000000) ...
Plan 9 from Bell Labs
...
Cheers,
Steve
