Hi Kever,
On 9/24/22 10:05, Kever Yang wrote:
Hi Quentin,
On 2022/9/22 20:12, Quentin Schulz wrote:
From: Quentin Schulz <quentin.sch...@theobroma-systems.com>
This event code represents the firmware source to use at boot.
Value 0 means using "standard" firmware source, value 1 means using
"alternative" firmware source.
For example, some hardware has the ability to force the BOOTROM to load
the bootloader from a secondary firmware source (say SD card) instead of
trying with the standard first and then the secondary. This event allows
the userspace to know which firmware source was requested *in hardware*.
Does this series patches need this patch?
I don't understand how can you affect the BOOTROM on PX30, I think PX30
does not
support this feature.
This is being discussed upstream with the kernel folks, this will likely
not be taken unfortunately. But let me explain how things work on our board:
We have a switch we can toggle to *electrically* disable eMMC/SPI
flashes and force booting from SD card, even if there is some TPL/SPL on
eMMC/SPI. This is required by the Q7 standard (via the
BIOS_DISABLE/BOOT_ALT signal).
Therefore, the SoC is not even aware of this switch (and does not need
to), it just cannot communicate with the eMMC/SPI so it continues to try
other boot media, with e.g. SD card or fallbacks to USB if nothing's
found. Nothing Rockchip specific here.
This version of the series needs the patch because it defines a new
event code that is then used in the device tree, see gpio-keys Device
Tree node where you have switch-bios-disable-n.
Cheers,
Quentin
