uart: pass register width in the coreboot table

Some SOCs (like pistachio, for instance) provide an 8250 compatible
UART, which has the same register layout, but mapped to a bus of a
different width.

Instead of adding a new driver for these controllers, it is better to
have coreboot report UART register width to libpayload, and have it
adjust the offsets accordingly when accessing the UART.

TEST=with the rest of the patches integrated depthcharge console messages
     show up when running on the FPGA board

Change-Id: I30b742146069450941164afb04641b967a214d6d
Signed-off-by: Patrick Georgi <>
Original-Commit-Id: 2c30845f269ec6ae1d53ddc5cda0b4320008fa42
Original-Change-Id: Ia0a37cd5f24a1ee4d0334f8a7e3da5df0069cec4
Original-Signed-off-by: Vadim Bendebury <>
Original-Reviewed-by: Aaron Durbin <>
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <>
14 files changed