Question about SPROM Readout

[Michael Büsch]

On Sat, 2010-12-11 at 11:39 -0600, Larry Finger wrote: 
> On 12/11/2010 02:47 AM, Michael Büsch wrote:
> > On Fri, 2010-12-10 at 16:06 -0600, Larry Finger wrote: 
> >> On the box with the SPROM located at 0x0800 rather than 0x1000, a readout cycle
> >> dumps data from whatever core happens to be mapped in the region 0x0 - 0xFFF. As
> >> this is usually not the ChipCommon core, the SPROM dump is usually garbage.
> >> Similarly, an SPROM write would overwrite lots of things.
> > 
> > No wait. The SPROM is not mapped into the core MMIO. It is mapped right
> > above it. So a core switch does not affect it.
> > Core window goes from 0-0x800 (0r 0-0x1000 on PCI-E). Above this, the
> > SPROM is statically mapped.
> 
> I see where the io_resource is mapped from 0x100 - 0x7FF, but not where it gets
> changed for PCIe.

We request and map all PCI regions with the sizes that the PCI subsystem
autodetects. So there is no need to "change" something for PCIe.
Note that the region we're interested in is the memory region,
not the I/O region.

> This is the SPROM dump I get on the box in question:
> 
> SPROM=$(find /sys -name ssb_sprom)
> cat $SPROM
> DE0168000187570600000000C0000A001400000080000F0047004700830164003009C0FC00000
> 00000000000000001030001000002000200010004000400000002000000030002000E00470000
> 28000001000500C0FCE005FFFFFFFF0A0011010800000000000000DB48000000000000FAAB000
> 00100000000008904B9C98887060010270100E0320000000000000702000000001A04FA000A0E
> 0B090E0200000100000000003F01FFFF0000FC03427B0200900700000000B80B0080140414040
> 0000000FA000000000000004C1DE204AA000000F401410000000000000000009B0800000000A2
> 04000000000000000000000000000000000000000000000000000000004E002A003905D10AB70
> 35517A92A6004420085030000000085033505B8005B0411000300B602640A0000320200001C08
> 46000000000000000000000000000000000000000000000000000000000000000000000000000
> 000010000004252434D5F544553545F5353494400000000000000000000000000000000000039
> 00000050000000C0FC00000000000000000000000000000000000000000000000000000000000
> 000000000000000000000000000000000
> 
> These are clearly not the data from a real SPROM.

Yeah, well. Maybe they simply relocated the SPROM again or changed the
way it has to be accessed in another way. Or there simply is a bug in
all that crazy SPROM detect logic that was added for PCIe devices.

-- 
Greetings Michael.