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authorPaul Gortmaker <paul.gortmaker@windriver.com>2011-12-30 23:53:08 -0500
committerKumar Gala <galak@kernel.crashing.org>2012-01-11 13:58:14 -0600
commitf0aec4ea3301f7db3a691ec0cbb5230e99cceb34 (patch)
treeff563f7ef8c292f077d1009917d296fc0e82ade8 /doc
parent3fd673cf363bc86ed42eff713d4e3506720e91a2 (diff)
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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>
Diffstat (limited to 'doc')
-rw-r--r--doc/README.sbc854834
1 files changed, 30 insertions, 4 deletions
diff --git a/doc/README.sbc8548 b/doc/README.sbc8548
index 5fa9c93..e6b8abe 100644
--- a/doc/README.sbc8548
+++ b/doc/README.sbc8548
@@ -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: