U-Boot for Wind River SBC834x Boards
The Wind River SBC834x board is a 6U form factor (not CPCI) reference
design that uses the MPC8347E or MPC8349E processor. U-Boot support
for this board is heavily based on the existing U-Boot support for
Freescale MPC8349 reference boards.
Support has been primarily tested on the SBC8349 version of the board,
although earlier versions were also tested on the SBC8347. The primary
difference in the two is the level of PCI functionality.
The flash type is intel 28F640Jx (4096x16) [one device]. Base address
is 0xFF80_0000 which is also where the Hardware Reset Configuration
Word (HRCW) is stored. Caution should be used to not reset the
board without having a valid HRCW in place (i.e. erased flash) as
then a Wind River ICE will be required to restore the HRCW and flash
Restoring a corrupted or missing flash image:
Note that U-boot versions up to and including 2009.06 had essentially
two copies of u-boot in flash; one at the very beginning, which set
the HRCW, and one at the very end, which was the image that was run.
As of this point in time, the two have been combined into just one
at the beginning of flash, which provides both the HRCW, and the image
that is executed. This frees up the remainder of flash for other uses.
Use of the u-boot command "fli" will indicate what parts are in use.
Details for storing U-boot to flash using a Wind River ICE can be found
on page 19 of the board manual (request ERG-00328-001). The following
is a summary of that information:
- Connect ICE and establish connection to it from WorkBench/OCD.
- Ensure you have background mode (BKM) in the OCD terminal window.
- Select the appropriate flash type (listed above)
- Prepare a u-boot image by using the Wind River Convert utility;
by using "Convert and Add file" on the ELF file from your build.
Convert from FF80_0000 to FFFF_FFFF (or to FF83_FFFF if you are
trying to preserve your old environment settings and user flash).
- Set the start address of the erase/flash process to FF80_0000
- Set the target RAM required to 64kB.
- Select sectors for erasing (see note on enviroment below)
- Select Erase and Reprogram.
Note that some versions of the register files used with Workbench
would zero some TSEC registers, which inhibits ethernet operation
by u-boot when this register file is played to the target. Using
"INN" in the OCD terminal window instead of "IN" before the "GO"
will not play the register file, and allow u-boot to use the TSEC
interface while executed from the ICE "GO" command.
Alternatively, you can locate the register file which will be named
WRS_SBC8349_PCT00328001.reg or similar) and "REM" out all the lines
beginning with "SCGA TSEC1" and "SCGA TSEC2". This allows you to
use all the remaining register file content.
If you wish to preserve your prior U-Boot environment settings,
then convert (and erase to) 0xFF83FFFF instead of 0xFFFFFFFF.
The size for converting (and erasing) must be at least as large
Updating U-Boot with U-Boot:
This procedure is very similar to other boards that have u-boot installed.
Assuming that the network has been configured, and that the new u-boot.bin
has been copied to the TFTP server, the commands are:
tftp 200000 u-boot.bin
protect off all
erase ff800000 ff83ffff
cp.b 200000 ff800000 40000
protect on all
You may wish to do a "md ff800000 20" operation as a prefix and postfix
to the above steps to inspect/compare the HRCW before/after as an extra
safety check before resetting the board upon completion of the reflash.
This board and U-Boot have been tested with PCI built in, on a SBC8349
and confirmed that the "pci" command showed the intel e1000 that was
present in the PCI slot. Note that if a 33MHz 32bit card is inserted
in the slot, then the whole board will clock down to a 33MHz base
clock instead of the default 66MHz. This will change the baud clocks
and mess up your serial console output. If you want to use a 33MHz PCI
card, then you should build a U-Boot with #undef PCI_66M in the
include/configs/sbc8349.h and store this to flash prior to powering down
the board and inserting the 33MHz PCI card.
By default PCI support is disabled to better support very early
revision MPC834x chips with possible PCI issues. Also PCI support is
untested on the sbc8347 variants at this point in time.
Paul Gortmaker, 01/2007