Progress on AMD x86 with gnumach

[Damien Zammit]

Hi,

I am trying to port gnumach to HP T620 which is an AMD FAM16h board 
running my port of coreboot.

With --disable-apic --enable-cpus=1 the board boots to a shell (but NIC 
locks up).

Under GNU/Linux, using command line options "noapic nolapic", the same 
thing happens and the NIC locks up even with vendor bios.

I believe there may be a wiring problem with the interrupt lines using 
PIC interrupts on this board, and the board may be only wired up for 
APIC usage.

Therefore, I want to make gnumach work with APIC interrupt routing on 
this board.

I have run into some problems when running with
--enable-apic --enable-cpus=2

1) The MADT table checksum is non-zero but still valid.

2) gnumach runs into a kernel page fault when attempting to validate the 
checksum:

    /* Check the checksum of the APIC */
    apic_checksum = acpi_checksum(apic, apic->header.length);

    /* NOT REACHED */

3) The board uses RSDPv2 not RSDPv1 table pointer, which is currently 
unsupported by gnumach.

I think if we fix these issues, the board will boot and NIC might even 
work as it is a 10ec:8168 realtek and supported by netdde.

Damien