I was thrilled to find Jonathon’s writeup, and I have been trying to get
the same setup working here. Some things I learned along the way:
OpenEmbedded is very very cool!
bitbake doesn’t work on eCryptfs file systems, as its path length
restrictions are not acceptable. One needs to build somewhere else (or
at
least put the TMP and SSTATE-CACHE directories elsewhere).
On my system (Ubuntu 12.04 64-bit), there was no binary called gmake,
which caused problems when generating the bit file with the Xilinx tool
chain. Solved this by linking /usr/bin/make to /usr/bin/gmake
Now, many many CPU cycles later, I am at the point of booting it. Well,
almost. What happens is that Das U-Boot is looking for an initial
ramdisk:
U-Boot 2013.01 (Aug 17 2013 - 06:32:40)
DRAM: 512 MiB
WARNING: Caches not enabled
MMC: zynq_sdhci: 0
SF: Detected S25FL256S with page size 64 KiB, total 32 MiB
In: serial
Out: serial
Err: serial
Net: Gem.e000b000
Hit any key to stop autoboot: 0
Copying Linux from SD to RAM…
Device: zynq_sdhci
Manufacturer ID: 1b
OEM: 534d
Name: 00000
Tran Speed: 50000000
Rd Block Len: 512
SD version 2.0
High Capacity: Yes
Capacity: 3.7 GiB
Bus Width: 4-bit
reading uImage
2855496 bytes read in 415 ms (6.6 MiB/s)
reading devicetree.dtb
21734 bytes read in 19 ms (1.1 MiB/s)
reading uramdisk.image.gz
** Unable to read file uramdisk.image.gz **
zynq-uboot>
Why? Because the environment says so:
sdboot=echo Copying Linux from SD to RAM… && mmcinfo && fatload mmc 0
0x3000000 ${kernel_image} && fatload mmc 0 0x2A00000 ${devicetree_image}
&& fatload mmc 0 0x2000000 ${ramdisk_image} && bootm 0x3000000 -
0x2A00000
That doesn’t seem quite right, I am assuming this should use the rootfs
in
the rootfs partition, shouldn’t it?
So my question is, am I missing something, or is the zynq Wiki page
missing a little section on how to set up the U-Boot environment
variables
in the flash?
Again, thanks for the great work, this is exciting stuff!
which caused problems when generating the bit file with the Xilinx tool
SF: Detected S25FL256S with page size 64 KiB, total 32 MiB
Tran Speed: 50000000
** Unable to read file uramdisk.image.gz **
So my question is, am I missing something, or is the zynq Wiki page
missing a little section on how to set up the U-Boot environment variables
in the flash?
I assume you figured out you need to modify the bootm command so it does
not look for the ramdisk? The default config from Xilinx is somewhat
obsessed with booting from a ramdisk I’m looking into some ways of
modifying the bootloader behavior without rebuilding it all the time.
MMC: zynq_sdhci: 0
Name: 00000
reading uramdisk.image.gz
in
modifying the bootloader behavior without rebuilding it all the time.
What zynq hardware are you using?
Philip
This is on a Zedboard. I did figure out that I need to change mboot
parameters, but I haven’t studied the whole setup enough to know what
all
else needs to change. So I thought I’d ask :-).
When you write about modifications, are you referring to more advanced
ways to load bitfiles rather than sticking them in the boot image?
/lib/modules/ for insmod to find it).
I was wondering how one would load a bit file after booting, so this
definitely a good tip. I will try that out once I get a little further
along.
Meanwhile I’ll figure out the right boot environment variables for my
Zedboard next.
MMC: zynq_sdhci: 0
Name: 00000
reading uramdisk.image.gz
in
modifying the bootloader behavior without rebuilding it all the time.
When you write about modifications, are you referring to more advanced
ways to load bitfiles rather than sticking them in the boot image?
Mods to fix the ramdisk issue.
You can load the bitfile from linux with cat foo.bin > /dev/xdevcfg
There is a magic promgen command to get the endianess correct though.
I’ll take a look at the wiki page and see if we can document the magic
command there.
sure, I load the bit file using /dev/xdevcfg (have to mknod, convert .bit
Thanks,
Jan
Hi Jan,
Take a look at
openembedded-core/build_zedboard/tmp-eglibc/work/zedboard_user_peripheral…/u-boot-xlnx/v2013…/include/configs/zynq_common.h
string search for /* Default environment */
After the system boots, I had to make a minor change to the fir filter
example. On the ZC702, I was getting a segfault as udev wasn’t
finding devcfg.
/sys/devices/amba.0/ lists f8007000.ps7-dev-cfg, modifying the call to
udev_enumerate_add_match_sysname to look for this device instead of
f8007000.devcfg and the example now works. Thanks to Jon and company
for this work!
I’m looking into some ways of