[U-Boot-Users] PPC440EPx/sequoia TLB question...

[Dave Littell]

Stefan Roese wrote:
> On Wednesday 23 April 2008, Dave Littell wrote:
>> >From …/board/amcc/sequoia/init.S:
>>
>> /* TLB-entry for Internal Registers & OCM */
>> tlbentry( 0xe0000000, SZ_16M, 0xe0000000, 0, AC_R|AC_W|AC_X|SA_I )
>>
>> Why is this memory region not marked Guarded?  It would seem to meet the
>> definition of “non-well-behaved”.
> 
> Why do you think this is the case?
> 
>> Also the TLB entry for SDRAM marks it Guarded, but that’s one area I
>> would think wouldn't need to be Guarded.
> 
> This could be a mistake. Should work without G bis set too. Please give it a 
> try and send a patch to fix it, if it works fine.
> 

Here goes (again):

Patch for AMCC Sequoia to remove the TLB Guarded attribute for SDRAM,
and add the Guarded attribute for Internal Registers & OCM.

diff -purN u-boot-1.3.2_base/board/amcc/sequoia/init.S u-boot-1.3.2/board/amcc/sequoia/init.S
--- u-boot-1.3.2_base/board/amcc/sequoia/init.S 2008-03-09 10:20:02.000000000 -0500
+++ u-boot-1.3.2/board/amcc/sequoia/init.S      2008-04-24 21:24:17.542281994 -0500
@@ -45,9 +45,9 @@ tlbtab:

        /* TLB-entry for DDR SDRAM (Up to 2GB) */
 #ifdef CONFIG_4xx_DCACHE
-       tlbentry( CFG_SDRAM_BASE, SZ_256M, CFG_SDRAM_BASE, 0, AC_R|AC_W|AC_X|SA_G)
+       tlbentry( CFG_SDRAM_BASE, SZ_256M, CFG_SDRAM_BASE, 0, AC_R|AC_W|AC_X)
 #else
-       tlbentry( CFG_SDRAM_BASE, SZ_256M, CFG_SDRAM_BASE, 0, AC_R|AC_W|AC_X|SA_G|SA_I )
+       tlbentry( CFG_SDRAM_BASE, SZ_256M, CFG_SDRAM_BASE, 0, AC_R|AC_W|AC_X|SA_I )
 #endif

        /* TLB-entry for EBC */
@@ -77,7 +77,7 @@ tlbtab:
        tlbentry( CFG_NAND_ADDR, SZ_1K, CFG_NAND_ADDR, 1, AC_R|AC_W|AC_X|SA_G|SA_I )

        /* TLB-entry for Internal Registers & OCM */
-       tlbentry( 0xe0000000, SZ_16M, 0xe0000000, 0,  AC_R|AC_W|AC_X|SA_I )
+       tlbentry( 0xe0000000, SZ_16M, 0xe0000000, 0,  AC_R|AC_W|AC_X|SA_G|SA_I )

        /*TLB-entry PCI registers*/
        tlbentry( 0xEEC00000, SZ_1K, 0xEEC00000, 1,  AC_R|AC_W|AC_X|SA_G|SA_I )


I sure hope this is better (from a line-wrapping perspective).


Dave