How to use the L1 D-Cache as RAM for p2020 board

[Jerry Zhang]

Hi,

I have to implement a test case on p2020(powerpc) board

1. Fill the all the 32-Kbyte L1 data cache

2. Some ambient operation like temperature changing

3. Check if the data of L1 data cache changes

I was told that in the start.S there is a scenario that use L1 D-Cache as
initial RAM,
https://source.codeaurora.org/external/qoriq/qoriq-components/u-boot/tree/arch/powerpc/cpu/mpc85xx/start.S?h=LSDK-21.08,
line 1100. After checking that, i still don't understand how exactly it
works and how to do it. Can anyone help to give a general description on
how to use L1 D-Cache as RAM?


Best Regards