Kernel kernel-7.2.9-skillfishos

SkillFishOS kernel — linux-tkg 7.2.9-skillfishos

Two builds, from the same tree and the same patches:

	uname -r	for
BC-250	7.2.9-skillfishos	the board, tuned -march=znver2
x64	7.2.9-skillfishos-x64	any other x86-64 machine, generic -march=x86-64

Installing the wrong one on the wrong machine gives a GRUB entry that loads and
then stops. The skillfishos-kernel package in our APT archive picks the right
one by looking at the hardware, and is the recommended way in.

What changed since 7.2.6

• The upstream releases 7.2.7, 7.2.8 and 7.2.9: 1633 fixes, 33 of them in the AMD
  graphics driver, none specific to gfx1013.
• Four patches of ours, 47 in all:
  • the platform security processor of the BC-250 is recognised (ccp: psp enabled),
    with two null-pointer fixes in the same driver that its firmware exposes;
  • the display driver clears hot-plug interrupts only for the connectors the
    chip has. It used to walk every slot of the table, and the unused ones hold
    handlers that assert when touched. Rebased on 7.2.9, where upstream wrapped the
    same call in a lock.

Measured on a BC-250, same board, 7.2.6 against 7.2.9: kernel call traces at
boot 2 → 0, kernel error lines 57 → 33 (what is left is the stock BIOS's own ACPI
errors), 40 of 40 compute units, 16 CPUs with C- and P-states, GPU fp32 10166 →
10163 / 10156 / 10107 GFLOPS over three runs. On x86-64 (Fujitsu TX1310 M3,
GTX 1050 Ti on nouveau): system running, no call traces, desktop up.

What linux-tkg gives

• BORE scheduler · 1000 Hz timer · tickless-idle · PREEMPT
• GCC -O3, NTsync and fsync for Proton and Wine

What we add on top

• the SMU messages the BC-250 firmware understands, so the voltage/frequency
  governor can set a clock and a voltage and read back what the chip really did
• the 40 compute units turned on at runtime, no kernel parameter, no reboot
• sched_ext, for the game scheduler
• the fixes that keep this board alive: KIQ bypass on a dead GPU, TTM guards,
  the KFD SDMA skip, the runlist TLB flush, GFXOFF off on gfx1013

Secure Boot — both images are signed with the SkillFishOS key. Register it
once with MokManager (secureboot/SkillFishOS-SB.cer in the repository) and
they boot with Secure Boot on; with it off the signature is simply ignored.

SHA-256

cd15e00c3facfa995fd7ec8110fb06808ef0618dd40b6d60dc552d71f1cfbbf6  linux-image-7.2.9-skillfishos_7.2.9-1_amd64.deb
51632d268ebd2f1c71807b90c601421d96b1bd46ddc59a00f2f53165f2127319  linux-headers-7.2.9-skillfishos_7.2.9-1_amd64.deb
080e1a7d5a04ae3c8ffd2031ea3ccf8a5e5faecff83605dd3ec40ba8362e33c5  linux-image-7.2.9-skillfishos-x64_7.2.9-1_amd64.deb
d0698f060f5ccee217cb30f420d915d623885f0f34f6a711824d6ba029618094  linux-headers-7.2.9-skillfishos-x64_7.2.9-1_amd64.deb