[OpenBIOS] r515 - dev/olpc/spiflash

[svn at openbios.org]

Author: wmb
Date: 2007-08-02 12:23:58 +0200 (Thu, 02 Aug 2007)
New Revision: 515

Modified:
   dev/olpc/spiflash/spiui.fth
Log:
SPI FLASH selftest - OLPC trac 2636 - Workaround a hardware design
deficiency by throttling access to the SPI FLASH in the /flash
selftest method.  If the CPU accesses the SPI FLASH too frequently,
the EC apparently can't do its instruction fetches, and the system
resets.  The workaround is to access the SPI FLASH in 64K chunks,
waiting 100 mS between chunks.




Modified: dev/olpc/spiflash/spiui.fth
===================================================================
--- dev/olpc/spiflash/spiui.fth	2007-08-02 05:35:04 UTC (rev 514)
+++ dev/olpc/spiflash/spiui.fth	2007-08-02 10:23:58 UTC (rev 515)
@@ -243,8 +243,17 @@
 0 value rom-va
 : selftest  ( -- error? )
    rom-va 0=  if  rom-pa /flash root-map-in to rom-va  then
-   rom-va flash-buf /flash move
 
+   \ This is a slower version of "rom-va flash-buf /flash lmove"
+   \ It works around the problem that continuous CPU access to the
+   \ SPI FLASH starves the EC of instruction fetch cycles, often
+   \ causing it to turn off the system.
+   rom-va flash-buf
+   /flash  0  do
+      rom-va i +  flash-buf i +  h# 1.0000 lmove
+      d# 100 ms
+   h# 1.0000 +loop
+
    \ Replace the manufacturing data block with all FF
    flash-buf mfg-data-offset +  /flash-block  h# ff fill