Data Structure alignment

Data Structure alignment

[TVKR]

Hi,
The PCI FW spec says PCI Data Structure must be DWORD aligned and I came
across this code the uses the following check

(RomHeader->PcirOffset & 3) != 0

The above is using the PcirOffset to do the check and not the actual data
structure itself (located at RomHeader + RomHeader->PcirOffset) Shouldn't
it instead be

(RomHeader + RomHeader->PcirOffset & 3) != 0

Thanks

Re: Data Structure alignment

[Tim Lewis]

I believe the option ROM header itself has an alignment requirement greater
than a DWORD. This is true whether it is from the option ROM BAR or whether
it is copied into allocated memory via AllocatePool. In this case, the check
you showed will still be adequate. But I am going from memory.

Thanks,
Tim

-----Original Message-----
From: edk2-devel <edk2-devel-bounces@lists.01.org> On Behalf Of TVKR
Sent: Thursday, March 14, 2019 1:47 PM
To: edk2-devel@lists.01.org
Subject: [edk2] Data Structure alignment

Hi,
The PCI FW spec says PCI Data Structure must be DWORD aligned and I came
across this code the uses the following check

(RomHeader->PcirOffset & 3) != 0

The above is using the PcirOffset to do the check and not the actual data
structure itself (located at RomHeader + RomHeader->PcirOffset) Shouldn't it
instead be

(RomHeader + RomHeader->PcirOffset & 3) != 0

Thanks
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