[SeaBIOS] Does SeaBIOS support eMMC?

Kevin O'Connor kevin at koconnor.net
Mon Jan 11 15:38:56 CET 2016


On Mon, Jan 11, 2016 at 02:46:24PM +0100, Alexander Couzens wrote:
> Hi Mario,
> 
> SeaBIOS supports eMMC, but it's a bit hacky.
> For eMMC in ACPI mode you have to add files containing the address
> of the eMMC to the cbfs.
> No idea, if eMMC in PCI mode works out-of-box.

There were some machines that apparently boot with the SDHCI
controller in PCI mode, but then coreboot implements some hardware
sequence to hide them via PCI and only advertise them via ACPI.  The
"etc/sdcard" mechanism was implemented as a hack to get around the
coreboot oddity (implementing an acpi dsdt parser isn't really an
option).

Detection of normal PCI SDHCI controllers should work fine.

> cbfstool coreboot.rom add -n etc/sdcard0 -f /tmp/sdcard0 -t raw
> cbfstool coreboot.rom add -n etc/sdcard1 -f /tmp/sdcard1 -t raw

The above can also be done with:
  cbfstool coreboot.rom add-int -i 0xd071c000 -n etc/sdcard0
  cbfstool coreboot.rom add-int -i 0xd071f000 -n etc/sdcard1

But, I wouldn't do that without inspecting the coreboot log (cbmem) to
verify that the device is in acpi mode and present at those addresses.

-Kevin



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