[coreboot] Discussion about dynamic PCI MMIO size on x86

Rudolf Marek r.marek at assembler.cz
Mon Jun 6 09:13:00 CEST 2016


Hi all,

Most of 32-bit kernels (Unix/OS/whatever) usually have PAE support, so in fact 
they can cope with 36 bits of memory. The CPU PAE support started around 
Pentium. Windows XP+ has support for this.

I think one can go with 2GB MMIO hole. The PCIe > 4GB is a question, I don't 
think Windows have good support for this. So, using 2GB memory hole and having 
MMIO < 4GB seems like a good idea.

Thanks
Rudolf




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