Add Sony PlayStation 5 (Oberon) uarch detection

[fbarchard]

Fixes #440

Summary

Identify the Sony PlayStation 5 (Oberon) CPU as its own microarchitecture instead of generic Zen 2.

Before this change, AMD family 17h, extended model 0x4 fell through the same case as Rome (extended model 0x3) and returned cpuinfo_uarch_zen2. A comment also mislabeled it as "Xbox Series X". The PS5 core is a custom Zen 2 with a cut-down 128-bit FPU, so it performs differently from standard Zen 2 (Rome, Matisse, Renoir, ...).

This PR adds cpuinfo_uarch_oberon (0x0020010F) and returns it for family 17h, extended model 0x4. That covers both known parts with this extended model:

Part	Family	Ext. Model	Base Model	Model	CPUID.1 EAX
Sony PlayStation 5 (Oberon), retail	17h	0x4	0x6	46h	0x00840F6x (stepping not published)
AMD 4700S Desktop Kit (Cardinal)	17h	0x4	0x7	47h	0x00840F70

Sources:

• Retail PS5, model 46h: the ps5-linux project, which runs Linux on retail consoles. It matches family 0x17, model 0x46 in arch/x86/kernel/cpu/amd.c to name the CPU "AMD Custom Zen 2 (Oberon)".
  x86/cpu/amd: set Oberon CPU model name (family 0x17, model 0x46) ps5-linux/ps5-linux-patches#29
• AMD 4700S, model 47h: InstLatx64 CPUID dump.
  http://users.atw.hu/instlatx64/AuthenticAMD/AuthenticAMD0840F70_K17_CPUID.txt

Standard Zen 2 parts keep returning cpuinfo_uarch_zen2: Rome 31h, Renoir 60h / Lucienne 68h, Matisse 71h, Van Gogh 90h / Mero 98h, and Mendocino A0h.

Also included

• Add cpuinfo_uarch_arden (0x00200110) for Microsoft Xbox Series X/S (Arden) / AMD 4800S: family 17h, extended model 0x8, model 84h, CPUID 0x00880F40. It was previously unhandled (cpuinfo_uarch_unknown). Unlike the PS5, it keeps standard Zen 2's full 256-bit FPU.
  Source: http://users.atw.hu/instlatx64/AuthenticAMD/AuthenticAMD0880F40_K17_CPUID.txt
• Add "Oberon" and "Arden" string mappings in tools/cpu-info.c.

[kimishpatel]

why is this deleted?

[kimishpatel]

nevermind. i see it is moved

[kimishpatel]

can you add in summary how the cpu info (hex id) was derived

[fbarchard]

For testing I wrote a little cpuid app and ran it but I dug up developer community references which are in the description.

The source is

#include <stdio.h>
static void CpuId(int eax, int info[4]) {
  __asm__ volatile("cpuid" : "=a"(info[0]), "=b"(info[1]), "=c"(info[2]), "=d"(info[3]) : "a"(eax), "c"(0));
}
int main(void) {
  int info[13] = {0};
  CpuId(1, info);
  printf("Family: 0x%x, Extended Model: 0x%x\n", ((info[0] >> 8) & 0xf) + ((info[0] >> 20) & 0xff), ((info[0] >> 12) & 0xf0) + ((info[0] >> 4) & 0xf));
  CpuId(0, info);
  info[4] = info[1]; info[5] = info[3]; info[6] = info[2];
  printf("Vendor: %s\n", (char*)(info + 4));
  CpuId(0x80000002, info); CpuId(0x80000003, info + 4); CpuId(0x80000004, info + 8);
  printf("Brand: %s\n", (char*)info);
  return 0;
}