Hi again.

After reverting 667bb59, ahci works fine in Linux, if I boot it with
-kernel, but grub seems to have some problems.
Grub2 gets to the rescue prompt. The disk and its partitions seem to
be detected correctly, but not the filesystem.
Grub-legacy (from illumos) complains about checksum verification
failures, supposedly in stage2.

I'm running with the current seabios and qemu gits. The command is
/home/xl0/work/nex/qemu/x86_64-softmmu/qemu-system-x86_64   -serial
stdio  -drive id=disk,file=debian.raw,if=none -device ahci,id=ahci
-device ide-drive,drive=disk,bus=ahci.0 -L
/home/xl0/work/nex/seabios-bin

In the seabios debug, I'm seeing a single ERROR from ahci, but not
sure if it's related:
init hard drives
ATA controller 0 at 1f0/3f4/c000 (irq 14 dev 9)
ATA controller 1 at 170/374/c008 (irq 15 dev 9)
init ahci
AHCI controller at 04.0, iobase f2060000, irq 11
32: pci read : f2060004
32: pci write: f2060004, 80000000 (0x00006ec4)
32: pci read : f2060000
32: pci read : f206000c
AHCI: cap 0x40141f05, ports_impl 0x3f
AHCI/0: probing
32: pci read : f2060118
32: pci read : f2060130
32: pci write: f2060114, 0 (0x00006e58)
32: pci read : f2060110
32: pci read : f2060120
32: pci read : f2060128
AHCI/0: link up
ebda moved from 9fc00 to 9f800
ebda moved from 9f800 to 9f400
32: pci write: f2060100, 9fc00 (0x00006c2c)
32: pci write: f2060108, 9fb00 (0x00006c2c)
32: pci read : f2060118
32: pci write: f2060118, 16 (0x00006c2c)
32: pci read : f2060118
32: pci write: f2060118, 4017 (0x00006c0c)
32: pci read : f2060138
AHCI/0: send cmd ...
32: pci write: f2060134, 1 (0x00006c04)
32: pci write: f2060138, 1 (0x00006c04)
32: pci read : f2060138
AHCI/0: ... finished, status 0x41, ERROR
32: pci read : f2060118
32: pci write: f2060118, c017 (0x00006c0c)
32: pci read : f2060138
AHCI/0: send cmd ...
32: pci write: f2060134, 1 (0x00006c04)
32: pci write: f2060138, 1 (0x00006c04)
32: pci read : f2060138
AHCI/0: ... finished, status 0x50, OK
AHCI/0: QEMU HARDDISK ATA-7 Hard-Disk (30720 MiBytes)
Registering bootable: AHCI/0: QEMU HARDDISK ATA-7 Hard-Disk (30720
MiBytes) (type:2 prio:101 data:fd610)
AHCI/1: probing

Full log attached.