sbc8548: enable ability to boot from alternate flash

This board has an 8MB soldered on flash, and a 64MB SODIMM
flash module.  Normally the board boots from the 8MB flash,
but the hardware can be configured for booting from the 64MB
flash as well by swapping CS0 and CS6.  This can be handy
for recovery purposes, or for supporting u-boot and VxBoot
at the same time.

To support this in u-boot, we need to have different BR0/OR0
and BR6/OR6 settings in place for when the board is configured
in this way, and a different TEXT_BASE needs to be used due
to the larger sector size of the 64MB flash module.

We introduce the suffix _8M and _64M for the BR0/BR6 and the
OR0/OR6 values so it is clear which is being used to map what
specific device.

The larger sector size (512k) of the alternate flash needs
a larger malloc pool, otherwise you'll get failures when
running saveenv, so bump it up accordingly.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Paul Gortmaker
2011-12-30 23:53:08 -05:00
committed by Kumar Gala
parent 3fd673cf36
commit f0aec4ea33
5 changed files with 142 additions and 27 deletions

View File

@@ -86,6 +86,33 @@ The "md" steps in the above are just a precautionary step that allow
you to confirm the u-boot version that was downloaded, and then confirm
that it was copied to flash.
The above assumes that you are using the default board settings which
have u-boot in the 8MB flash, tied to /CS0.
If you are running the default 8MB /CS0 settings but want to store an
image in the SODIMM that is built with CONFIG_SYS_ALT_BOOT enabled,
(as a backup, etc) then the steps will become:
tftp u-boot.bin
md 200000 10
protect off all
era eff00000 efffffff
cp.b 200000 eff00000 100000
md eff00000 10
protect on all
Finally, if you are running the alternate 64MB /CS0 settings and want
to update the in-use u-boot image, then (again with CONFIG_SYS_ALT_BOOT
enabled) the steps will become:
tftp u-boot.bin
md 200000 10
protect off all
era fff00000 ffffffff
cp.b 200000 fff00000 100000
md fff00000 10
protect on all
Hardware Reference:
===================
@@ -127,10 +154,9 @@ JP19 PCI mode PCI PCI-X
onto /CS0 and the SODIMM flash on /CS6 (default). When JP12
is jumpered parallel to the LBC-SDRAM, then /CS0 is for the
SODIMM flash and /CS6 is for the boot flash. Note that in this
alternate setting, you also need to switch SW2.8 to ON. Currently
u-boot doesn't support booting off the SODIMM in this alternate
setting without manually altering BR0/OR0 and BR6/OR6 in the
board config file appropriately.
alternate setting, you also need to switch SW2.8 to ON.
See the setting CONFIG_SYS_ALT_BOOT if you want to use this setting
and boot u-boot from the 64MB SODIMM
Switches: