On Sun, Oct 6, 2013 at 1:43 AM, Corey Osgood <[email protected]> wrote: > After sending the last message, I've done a little more debugging and dumped > cr0, and also checked the C7 FCR, everything indicates the cache is properly > enabled and not in NoWriteThrough mode, although I have very little C7 > specific information and none of it relating to cache. > > So, I'm now looking elsewhere, and at the moment I'm looking at MTRRs. All > the fixed MTRRs, under coreboot, are 0'd out, and variable are all type 6 > (WB?), as can be seen in the attached boot log. Here's the way the stock > BIOS sets them up:
MTRR: Physical address space: 0x0000000000000000 - 0x0000000004000000 size 0x04000000 type 0 0x0000000004000000 - 0x000000003e000000 size 0x3a000000 type 6 0x000000003e000000 - 0x00000000fff80000 size 0xc1f80000 type 0 0x00000000fff80000 - 0x0000000100000000 size 0x00080000 type 5 0->64MiB is uncacheable 64MiB->992MiB is cacheable 992MiB-> -512KiB is uncacheable -512KiB->4GiB is write-protect The fixed MTRRs cover the first 1MiB so it's not surprising those are zero'd out. The only odd thing I see in the variable MTRRs is the ROM not being marked as WP, but I suspect that is from CONFIG_CACHE_ROM not being enabled. Looking through your resources I don't see anything that covers memory during read resources (flags field): #define IORESOURCE_MEM 0x00000200 #define IORESOURCE_CACHEABLE 0x00004000 Any flags with the bits 0x4200 should be cacheable memory. DOMAIN: 0000 resource base c0000 size 3df40000 align 0 gran 0 limit 0 flags e0004200 index b The above shows up ding assign resources. The MTRR code has a 64MiB min alignment which makes me think that is where the 64MiB->992MiB comes from. I would do two things: 1. Add all ram resources during the read_resources() step. That way the IO hole can be properly picked. 2. Ensure all the memory you know exist are added to the resource list, including 0 -> 64MiB. Hope that helps. -Aaron -- coreboot mailing list: [email protected] http://www.coreboot.org/mailman/listinfo/coreboot
