Hi Kever,
On 1/26/24 09:58, Kever Yang wrote:
Hi Quentin,
On 2024/1/24 19:04, Quentin Schulz wrote:
Hi Kever,
On 1/24/24 11:35, Kever Yang wrote:
Hi Quentin,
On 2024/1/23 22:49, Quentin Schulz wrote:
From: Quentin Schulz <quentin.sch...@theobroma-systems.com>
Since commit 9e644284ab81 ("dm: core: Report bootph-pre-ram/sram
node as
pre-reloc after relocation"), bootph-pre-ram doesn't make U-Boot proper
bind the device before relocation.
While this is usually not much of an issue, it is when there's a lookup
for devices by code running before the relocation. Such is the case of
env_init() which calls env_driver_lookup() which calls
env_get_location() which is a weak symbol and may call
arch_env_get_location() also a weak symbol. Those are two functions
that
may traverse UCLASS to find some devices (e.g.
board/theobroma-systems/common/common.c:arch_env_get_location()).
This sounds like we need to update arch_env_get_location() instead of
enable mmc driver
before relocate, because you we don't really need the mmc driver
works here, there is no
access requirement to mmc at this point, right?
All Rockchip SoCs except RK3588(S) and RK356x have it done this way, a
little bit of consistency wouldn't hurt :)
My point is not about you can not enabe the emmc before relocate, maybe
I'm not clear enough for the reason.
All the driver bind/probed before the relocation will have to do the
init sequence again later after relocation.
The emmc driver cost pretty much time at init, we should avoid to
duplicate the init process if possible.
For this patch, you want to make it pre-relocate because you want to
make sure the emmc is available for ENVL_MMC,
but there is no read or write requirement to the emmc at this point,
which means we don't have to init the emmc at this point,
maybe we can check if the driver is enable if enough.
Now I need to know which SoC we are booting at build time so I can check
which drivers are supposed to be built, check those symbols are enabled,
then traverse the Device Tree with hardcoded DT node to locations of
MMC, SPI flash controllers, check if those are enabled and finger-cross
that those drivers will actually bind/probe properly later on. That's A
LOT of checks to be made.
I need to be able to find out if the device that was used to load
U-Boot proper is an MMC device so that I can tell
arch_env_get_location() to return ENVL_MMC; in that case.
For that, I've used uclass_find_device_by_ofnode() which parses the
list of devices registered in the UCLASS_MMC (for that scenario). I
assume the only requirement is that the device needs to be bound, not
probed (haven't checked). If there's another way to do this
**properly**, I'm all ears. I would likely need to do the same for the
SPI controllers but since none of our RK3588-based products have
SPI-NOR, I don't need those (but it works on RK3399 just fine).
I still think there's value in having consistency between all Rockchip
SoCs (and if applicable to other SoC vendors, then those as well).
This is the point I do care, because I don't want the boot loader too
heavy, especially the SPL and the U-Boot proper before relocate,
although we can enable all the feature in it in technically.
Even for the rk3588 which is kind of powerful soc, still many project
need it to boot fast, which require to remove all the redundant
operation in the boot process.
It's a bit surprising to start caring about boot speed to justify not
binding some drivers on the fastest (to date) Rockchip SoC while all
much slower SoCs have this enabled :)
For the feature record "spl-boot-device" in SPL and read in out in
U-Boot proper, and then Swap mmc0 and mmc1 in boot_targets if booted
from SD-Card.
It's OK for Theobroma-Systems's board to enable it, but seems not also
required by other boards.
Usually we consider the system in two stage: bootloader/BIOS
stage(including all firmware before kernel) and OS stage(including
kernel and Linux/Android OS),
and for those boards(eg. PC like) do have two different storage medium,
they put bootloader in SPI flash and put OS firmware in other storage
like emmc/SSD/SDcard.
In this case the U-Boot boot target does not need to know where it's from;
in another case which supports firmware update from SD card, the U-Boot
boot target needs to set SDCard as highest priority, also no need to
know where the U-Boot from.
So... this means we need a different U-Boot if we're booting from SD
card so it can know which boot target to use by default? Or a different
environment for SD card? or requiring the user to stop the boot process
and manually change the priority? Or what are you suggesting?
It all boils down to sane defaults. If I understand correctly, you want
people to have systems which can boot really fast by default but don't
mind if people need to tinker to get things working properly. I would
prefer to have most things working by default and let people tinker to
make things faster.
There are a couple of drivers that are selected when using Rockchip
boards that shouldn't be necessary, e.g. ADC support, SPI flash
controller (to name the few that we have on RK3588 that we don't need
for Jaguar now), there are also DT nodes that are enabled by default in
rk3588(s)-u-boot.dtsi that aren't necessary for my use case, this also
increases the size of the DTB. I don't really get where you want the
line between convenience and speed be right now. It'd be nice to have
some kind of consensus/guideline if you already have one in mind, at
least I'd know where we want to go with this :)
Reminder that if people want to make things faster, they can still
override this in their own -u-boot.dtsi by deleting bootph-all and
adding bootph-pre-ream instead.
I can keep this in rk3588-jaguar-u-boot.dtsi sure, I'll have to do the
same for another RK3588 board soon as well.
So, up to you. I gather you'd prefer we have this in
rk3588-jaguar-u-boot.dtsi so will do this for v2 except if you're saying
otherwise.
Cheers,
Quentin
