Effect of CACHE enabling on bootloader execution time

Abhi44810

Hello Friends,

Query Description:

Currently I am looking into the time required for bootloader execution.

I have binary image of size ~600K and flashed it using NOR writer.

The time taken by bootloader (EMIFA ROM fast boot with AIS) for it's execution and reaching till main() function is coming as ~1.2 Sec.

I am finding the ways to reduce this period. While going through "Using the TMS320DM643x Bootloader.pdf", I found that CACHE is disabled during boot process.

So I am thinking of CACHE enabling at the start of boot process.

Query:

1. If I enable the CACHE at boot time, will there will be any effect on time required for bootloader execution.

Thanks,

Abhijeet

over 14 years ago

0 Varada Bellary over 14 years ago

TI__Expert 5750 points

Abhijeet,

Enabling cache while boot may cause undesired side effects.

What you can try is a 2 step boot.

Step 1 : Primary bootloader copies secondary bootloader code from NOR to L2 flash. Jump to secondary boot

Step 2 : Secondary boot loader executes from L2. Sets up DMAs, to copy the remainder of code and data from NOR to DDR. jump to main().

Hope this helps.

0 Abhi44810 over 14 years ago in reply to Varada Bellary

Prodigy 190 points

Varada,

Thank you for the reply.

If I use 2 stage bootloader, how much time will be required for copying of code & data (~600k) and to reach till main() function.

The expected period of reaching till main() fuction is 300ms. The complete bootloader functionality execution is expected to complete within 300ms.

So will it be possible to achieve this performance by using 2 stage bootloader.

- Abhijeet

0 Abhi44810 over 14 years ago in reply to Abhi44810

Prodigy 190 points

Varada,

If you can suggest the reference material (Source Code, pdf's, URL) for 2 stage bootloader implementation that will be really helpful to get it started.

Thanks,

Abhijeet