x86: Allow locating the UART from ACPI tables
When coreboot does not pass a UART in its sysinfo struct, there is no
easy way to find it out.
Since coreboot does not actually init the serial device when serial is
disabled, it is not possible to make it add this information to the
sysinfo table.
Add a way to obtain this information from the DBG2 ACPI table, which is
normally set up by coreboot.
For now this only supports a memory-mapped 16550-style UART.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig
index 7faf678..f4767c8 100644
--- a/drivers/serial/Kconfig
+++ b/drivers/serial/Kconfig
@@ -669,6 +669,16 @@
a serial console on any platform without needing to change the
device tree, etc.
+config COREBOOT_SERIAL_FROM_DBG2
+ bool "Obtain UART from ACPI tables"
+ depends on COREBOOT_SERIAL
+ default y if !SPL
+ help
+ Select this to try to find a DBG2 record in the ACPI tables, in the
+ event that coreboot does not provide information about the UART in the
+ normal sysinfo tables. This provides a useful fallback when serial
+ is not enabled in coreboot.
+
config CORTINA_UART
bool "Cortina UART support"
depends on DM_SERIAL