If for some reason, TSC timer frequency cannot be determined from
hardware, nor is it specified in the device tree, U-Boot will panic
resulting in endless reset during boot.
Let's define a default TSC timer frequency using the Kconfig value
CONFIG_X86_TSC_TIMER_FREQ (note: #include must be used instead of
/include/ otherwise the macro is not pre-processed).
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Use this UART to improve the compatibility of U-Boot when used as a
coreboot payload.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
This is currently missing and without it the i8254 beeper driver
won't work.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
It was observed sometimes U-Boot as the coreboot payload fails to
boot on QEMU. This is because TSC calibration fails with no valid
frequency. This adds default TSC frequency in the device tree.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Currently building U-Boot as the coreboot payload requires user
to change the build configuration for a specific board during
menuconfig process. This uses the board's native device tree
to configure the hardware. For example, the device tree provides
PCI address range for the PCI host controller and U-Boot will
re-program all PCI devices' BAR to be within this range. In order
to make sure we don't mess up the hardware, we should guarantee
the range matches what coreboot programs the chipset.
But we really should make the coreboot payload support easier.
Just like EFI payload, we can create a generic coreboot payload
for all x86 boards as well. The payload is configured to include
as many generic drivers as possible. All stuff that touches low
level initialization are not allowed as such is the coreboot's
responsibility. Platform specific drivers (like gpio, spi, etc)
are not included.
Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Christian Gmeiner <christian.gmeiner@gmail.com>
