On 14 March 2015 at 08:26, Scott Bambrough <scott.bambrough@linaro.org> wrote:
My thoughts are: current dtb + hisilicon bootloader should be the default for the next week- we should revisit this at the end of the week, or earlier if development progress warrants it
My concerns with: psci enabled dtb + UEFI as a default
- can we reliably flash the eMMC using UEFI? If that isn't working the only way to update the eMMC will be to use the tool in burn-boot.
At first, we can't flash the eMMC using UEFI since USB driver isn't ready in UEFI yet.
In the second, burn-boot can't flash anything into eMMC. We could download l-loader.bin into SRAM, and l-loader.bin flash itself into eMMC.
And there's a limitation on l-loader.bin could only flash 128KB into eMMC.
In the third, we could only flash images into eMMC in recovery mode (implemented in ATF). And there's the limitation on flashing image
within 128MB size.
If we stick to use ATF+UEFI as release, the simplest way is to fix the limitation in recovery mode. I doubt that implementing flashing in UEFI
may cost a lot time.
- we lose the ability to boot from SD card if we do this as SD support isn't implemented in UEFI at this time.- at present I believe we have only implemented enough of PSCI to allow all the cores to be enabled
Yes. And system reset in PSCI is also ready. It'll be merged right now.
- i believe we need to check if the missing PSCI calls cause a problem when PSCI is enabled in the kernel, particularly with thermal/power management, we don't want unsuspecting people frying their SoC's
There's no any relationship between PSCI and thermal/power management. The thermal driver works without any dependance on boot loader.
cpufreq driver is depend on loading MCU.
- i believe MCU loading isn't finished yet in ATF, this will cause power management problems, and possible overheating - it is needed
Yes.
That being said I haven't had a chance to play with ARM TF + UEFI yet. Anyone have any comments based on experience?I'm all for moving to ARM TF + UEFI as the default ASAP, but I'm not sure this is quite the right time. I don't want to lose precious development time due to flashing issues or dead boards.
DDR800 isn't ready in ATF yet. Sometimes (50%) may cause board hang. We compared the code with hisilicon bootloader. It seems that everything is same already.
Regards
Haojian
ScottOn Fri, Mar 13, 2015 at 4:23 AM, Koen Kooi <koen.kooi@linaro.org> wrote:On 13 March 2015 at 08:52, Fathi Boudra <fathi.boudra@linaro.org> wrote:Hi,
There's a change pending to enable PSCI on HiKey:
https://github.com/96boards/linux/pull/15
A regression is introduced when using HiSilicon bootloader:
we'll have one core when using Hisilicon's bootloader.
Here's the summary:
* current dtb + hisilicon bootloader: boot images, all cores enabled
* current dtb + uefi: boot images, one core enabled
* psci enabled dtb + hisilicon bootloader: boot images, one core enabled
* psci enabled dtb + uefi: boot images, all cores enabled
It won't be much of an issue since the long term plan is to deprecate HiSilicon
bootloader in favor of UEFI. Unfortunately, UEFI isn't feature complete (SD
card support missing, flash to eMMC limited to 128M, etc...).
In the meantime, moving forward it's proposed to provide a legacy dtbA dt*b*, not a dt*s*, right?and use
the PSCI enabled combination (UEFI + kernel) as the default as it is the
long term plan. It mitigates the issue for people using HiSilicon bootloader
while it enables people using UEFI.
Another option is to keep the status quo until UEFI is there
(speculation is "in 2 weeks")
and switch the default dtb at that time.
The question is which default dtb should be used? Opinions?I would apply the psci patch and encourage people to upgrade their binary only vendor bootloader to the uefi one. If someone wants to stay with the huawei bootloader, they'll get one core or they can fix it themselves. The hikey isn't for sale yet, so I'd grab onto every chance to get people to use the release sw.If that's too harsh I can see the value in providing a download for the non-psci dtb.regards,Koen
--