[SeaBIOS] wrong memsize in smbios_init()

[Gleb Natapov]

On Wed, Jan 06, 2010 at 05:48:29PM -0500, Kevin O'Connor wrote:
> On Wed, Jan 06, 2010 at 09:13:13PM +0100, Sebastian Herbszt wrote:
> > RamSizeOver4G = "total ram" - "start of pci hole" (e.g. 0xe0000000
> > in qemu, 0xc0000000 in bochs)
> 
> The intent of RamSizeOver4G is to list the amount of ram mapped above
> 0x100000000.  So, if one specified 4096MB of ram, I'd expect qemu to
> map it so that SeaBIOS had RamSize=0xe0000000 and
> RamSizeOver4G=0x10000000.
> 
> >Adding 4GB is wrong. With 33 GB of RAM
> > i end up with 16+16+2 instead of 16+16+1 in smbios tables.
> > The patch below fixes it for me.
> 
> I'm not sure what smbios is expecting - if it's looking for the
> addresses of mapped memory then the current code looks correct (in the
> scenario above, memory is mapped up to 0x110000000).  If it's looking
> for the total memory, then I agree your change makes sense (in the
> above scenario, the total ram is 0x100000000).
> 
It looks like different tables looks for different things, 

Table 16 describes how much memory board supports (should be
bigger or equal to RamSizeOver4G+RamSize if hot plug memory is not
supported I guess). Just picking a big enough number is good enough.

Table 17 describes how much memory installed in each DIMM. Sum of all
sizes should be equal to RamSizeOver4G+RamSize.

Table 19 spec says it provides the address mapping for a Physical
Memory Array (table 16). One structure is present for each contiguous
address range described. Nobody know what this means. I checked 3
computers and got 3 different interpretations:

On computer with 4G memory:
  Handle 0x0026, DMI type 19, 15 bytes
  Memory Array Mapped Address
          Starting Address: 0x00000000000
          Ending Address: 0x0012FFFFFFF
          Range Size: 4864 MB
          Physical Array Handle: 0x0025
          Partition Width: 0
Here Ending Address is RamSizeOver4G + 4G

On computer with 16G memory:
  Handle 0x003D, DMI type 19, 15 bytes
  Memory Array Mapped Address
          Starting Address: 0x00000000000
          Ending Address: 0x003FFFFFFFF
          Range Size: 16 GB
          Physical Array Handle: 0x0024
          Partition Width: 0
Here Ending Address is RamSizeOver4G+RamSize

On another computer with 16G memory:
  Handle 0x0045, DMI type 19, 15 bytes
  Memory Array Mapped Address
          Starting Address: 0x00000000000
          Ending Address: 0x3C3FFFFFFFF
          Range Size: 3856 GB
          Physical Array Handle: 0x003C
          Partition Width: 0
Here it is just a huge number.

So apparently nobody understands what this table is about.

Table 20 looks like it maps physical address ranges to DIMMs
and physical address ranges is from 0 to RamSizeOver4G+RamSize.
One of my test machines does not have this table at all.

Whatever change we do to smbios table we need to validate it with SVVP
test first.

--
			Gleb.