The wiki is being retired!

Documentation is now handled by the same processes we use for code: Add something to the Documentation/ directory in the coreboot repo, and it will be rendered to https://doc.coreboot.org/. Contributions welcome!

Hello. I'll have some more info soon enough. For now, remember this:

$ flashrom -pinternal:amd_imc_force=yes -w coreboot.rom

Now chances are that will brick your system if you're not already booting coreboot. Expect to do an external flash initially.

GPIO layout

This information should not be considered reliable in any way, shape or form

GPIO57 - OUT - controls WLAN (rfkill pin on minipcie slot)
GPIO54 - OUT - seems to control bluetooth

General Purpose Events layout

GEVENT3 -> GPE3 - EC SCI
GEVENT23 -> GPE23 - EC SMI
GEVENT22 -> GPE22 - Lid

EC headaches

To ACPI or not to ACPI

The EC likes to start up in APM mode. In APM mode, it will generate an SMI whenever an external event occurs. To make it generate SCIs instead, and play nicely with ACPI, we need to tell it to go to ACPI mode.

The MMIO dilemma

The EC RAM, which contains the batterry/AC etc information is normally accessed by read commands on the EC index I/O ports (0x62 and 0x66). The EC will also respond to LPC memory read/write cycles in the address range 0xff000000 + 0x1000. In order for this to work, the chipset must pass MMIO accesses in this range to the LPC bridge, which in turn, must decode them to the LPC bus.

This can't work if there is something else using that address range, so any system with 16MiB is out of the question. Luckily, the 1035dx uses a 4 MiB chip, so that's a non-issue. As a bonus, the LPC bridge can map a 4 KiB MMIO window on the LPC bus (or two, I can't remember).

The EC RAM is at an offset of 0x800 from the MMIO base address. The current compal/ene932 ACPI implementation does not handle MMIO. This should be easily fixable with some preprocessor love.

The Caps Lock LED

<mrnuke> roxfan (and you too carldani): If I take the EC out of ACPI mode and put it back in, it works
<mrnuke> turns out the EC has this "OS not responding, oh shit, gotta blink Caps Lock feature"
<patrickg> hah
<carldani> mrnuke: ah. hardware. I'm lovin' it
<mrnuke> So I can't put it in ACPI mode before OS loads
<mrnuke> I'll deal with that "feature" later, I guess
<mrnuke> It works on parrot because they handle this stuff (ACPI mode on/off) using SMM
<mrnuke> it would be sick if we needed SMM just to get the caps lock LED to function
<patrickg> activating SMM is a good idea anyhow, if only to make sure there's some sane code doing the lock down
<mrnuke> patrickg: I'll deal with SMM later
<mrnuke> I'll make a note on the wiki though so that I don't forget

Doing that can be accomplished in userspace by uberawesome blackmagic:

# iotools io_write8 0x66 0x59 && iotools io_write8 0x62 0xe9 # Put EC in APM mode
# iotools io_write8 0x66 0x59 && iotools io_write8 0x62 0xe8 # Put EC in ACPI mode

Board:hp/pavilion m6 1035dx