Hi Ed,
On Thu, 2010-01-21 at 15:06 -0700, Swarthout Edward L-SWARTHOU wrote:
From: Kumar Gala
Its possible that we try and copy the boot page code out of flash into
a DDR location that doesn't have a TLB cover it. For example, if we have 3G of DDR we typically only map the first 2G. In the cases of 4G+ this wasn't an issue since the reset page TLB mapping covered the last page of memory which we wanted to copy to.
We now change the physical address of the reset page TLB to map to the
true physical location of the boot page code, copy and than set the TLB back to its 1:1 mapping of the reset page.
Why should a boot page TLB still exist? And if it does exist, it may be serving a good purpose and shouldn't be touched.
I imagine Kumar assumed the bootpage was only used for its "intended" purpose? Our boards have a large flash mapped on top of the original bootpage, which caused problems for me too.
Why not just pick an unused virtual address and map it to bootpg?
You can actually do what you describe since commit 5ccd29c3679b3669b0bde5c501c1aa0f325a7acb. The CONFIG_BPTR_VIRT_ADDR feature is enabled for the XPedite5370 in commit 48618126f78f05042dae428811809b594f747eb9.
This TLB grabbing is giving me problems on my board where I have the original 1M bootpage mapped to CPC sram and I want to keep active.
I believe reproducing 48618126f78f05042dae428811809b594f747eb9 for your board should be a workaround.
Best, Peter