Fast Boot related question on DRA821

Hi Kaushik,

Kaushik . said:

a) We want to use only A72 core we are looking at option of using Fast Boot. Does Fast boot support secure boot is u-boot used in Fast boot mode. 

No fast boot supported in the SDK. But we can optimize the boot time by optimizing the device. What exactly are you looking for when you mean fast boot?
You just want to boot Linux & get to command prompt or you have a real use case with a timing constraint?

Kaushik . said:

b) How can we boot Kernel without u-boot and with secure boot option.

When you mean secure boot, do you mean boot on HS or high secure devices?

Kaushik . said:

c) How much time is taken from initial power On to start boot from MMC (Time taken from DMSC and BootRom). 

It is of the order of 18-20S with full fledged file system booting to prompt. But as mentioned above if it is just booting to linux prompt we can try to a minimal file system & minimal DT to get to Linux prompt much faster.

Best Regards,
Keerthy

Keerty Said. 

No fast boot supported in the SDK. But we can optimize the boot time by optimizing the device. What exactly are you looking for when you mean fast boot?
You just want to boot Linux & get to command prompt or you have a real use case with a timing constraint?

 >> My understand was fastboot is an option to get our device boot faster. We have customer requirement "the kernel must be able to boot in less than 350ms (from kernel first instruction until pid 1 is spawned)" 

Keerty replied.

When you mean secure boot, do you mean boot on HS or high secure devices?

>> We are using HS (high secure device) is there any way we can boot kernel without u-boot and if there is a way how is secure handled. 

Keerty replied.

It is of the order of 18-20S with full fledged file system booting to prompt. But as mentioned above if it is just booting to linux prompt we can try to a minimal file system & minimal DT to get to Linux prompt much faster.

>> No i require only time take for DMSC and BootRom before it execute u-boot. 

We want to achive kernel boot time of around 350 ms so we are looking at exploring options. 

a) Fastboot

b) Booting without U-boot. 

Please give more understand of above.

Note we are using DR821A board and only A72 core not R5 cores. 

Regards

kaushik

Kaushik . said:

We want to achive kernel boot time of around 350 ms so we are looking at exploring options. 

a) Fastboot

b) Booting without U-boot. 

Please give more understand of above.

Note we are using DR821A board and only A72 core not R5 cores. 

There is no support for fast boot as mentioned earlier.

Now there is a way to boot without u-boot. You will have to use the RTOS SBL bootloader to boot Linux.
That said the SoC architecture clearly mandates booting the R5F first either with SPL or SBL, loading sysfw to DMSC
& then loading A72. So with all this design considerations & minimal filesystem we can achieve anywhere between 1.5-2S.

I highly doubt getting anywhere < 500 ms.

Best Regards,
Keerthy

Thanks Keerth for reply

One request 

Can i get boot sequence diagram for loading A72 Kernel without uboot. 

Also booting A72 with U-boot. (Please send us files loaded).

My understand is in both the above cases booting R5F is mandatory is this correct. 

Regards

Kaushik