Only one CPU core is detected

[MatejHorvat]

Similar to #13257. On this dual-core computer, only one core is detected (hrev54154+31). I have updated the BIOS to the latest version and this doesn't fix it. However, FreeBSD detects both cores.

[waddlesplash]

KERN: smp: using ACPI to detect MP configuration
KERN: smp: Failed to find MADT!
KERN: smp_mp_probe: entry base 0x9fc00, limit 0xa0000
KERN: smp_mp_probe: entry base 0xf0000, limit 0x100000
KERN: smp_mp_probe: found floating pointer structure at 0x000fccf0
KERN: smp: intel mp version 1.4, virtual wire compatibility mode.
KERN: smp: invalid config table signature, aborting

[MatejHorvat]

If it helps, this is what FreeBSD's dmesg says:

FreeBSD/SMP: Multiprocessor System Detected: 2 CPUs
FreeBSD/SMP: 1 package(s) x 2 core(s)
Firmware Warning (ACPI): Incorrect checksum in table [XSDT] - 0x89, should be 0xFD (20171214/tbprint-337)
Firmware Warning (ACPI): Optional FADT field Pm2ControlBlock has valid Length but zero Address: 0x0000000000000000/0x1 (20171214/tbfadt-796)
ioapic0: Changing APIC ID to 0
ioapic0 <Version 2.1> irqs 0-23 on motherboard
SMP: AP CPU #1 Launched!
<...>
cpu0: <ACPI CPU> on acpi0
cpu1: <ACPI CPU> on acpi0

[waddlesplash]

So, FreeBSD also says the checksum is invalid, but continues anyway. I'm not sure that's very wise...

tqh, what do you think we should do here?

[tqh]

We don't use ACPICA for that I think. It is some early Haiku specific kernel code, so I think someone that knows about the multiprocessor config needs to take a look. Or we'd need to use ACPICA early in boot process instead.

[korli]

acpica isn't available in the boot loader (and won't be).

[korli]

​https://review.haiku-os.org/c/haiku/+/2740

[tqh]

Use of ACPI tables to init hardware is parts where others know better. Not sure what the implications of ignoring a broken checksum would be. I probably would fail, but add a boot flag to circumvent failing.

[korli]

merged in hrev54231

[MatejHorvat]

Both cores are detected now. If this is a satisfactory solution, then this ticket can be closed.