[Discuss-gnuradio] Booting Zynq/Gnuradio

[Jan Schiefer]

Hi everybody,

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!

Regards,
   Jan, ac7td