Hi misc@, <https://www.openbsd.org/amd64.html> mentions this:
"Supported hardware: Processors All versions of the AMD Athlon 64 processors and their clones are supported." What are the minimum requirements with respect to chipsets? I see that e.g. QEMU defaults to <https://en.wikipedia.org/wiki/Intel_440FX> This goes back to Pentium II/Pentium Pro. There is not a single real machine around with such a chipset supporting anything 64 bit. In addition sys/arch/amd64/include/vmparam.h has this: #define MAXDSIZ ((paddr_t)128*1024*1024*1024) That's 128GB. Could you please point me to the first chipsets supporting those amounts of memory physically. My understanding is that the so called memory controller hubs got integrated into the CPUs. So what is the first CPU supporting those 128GB physically? I am having a hard time getting my hands on the PC architecture and I would really like to understand why amd64 supports processor chipset combinations which do not exist in real life. Currently only reading documentation provided by Intel. Athlon 64 seems to be on the same timeline than Pentium 4. At that time there where no motherboards around supporting more than 8GB physical memory, no? For example, I am having difficulties understanding things like isa0 at pcib0 isadma0 at isa0 pckbc0 at isa0 port 0x60/5 irq 1 irq 12 in the dmesg. Reading the various chipset documentations there, of course, is no ISA bus anywhere since a very long time and things just have been produced for compatibility with existing OSes. Enforcing some ISA constraints on hardware which does not need any of those constraints is hard to understand for someone never having followed hardware development since the early 90s. I could really need some pointers on what documents to read, given they are around 800 pages long. Thank you. -- Christian
