PROCESSOR-SDK-AM64X: Purpose of Defining Different Modes and Stacks in SBL Boot-Up Assembly Code

Tool/software:

Hi,  

in C:\ti\mcu_plus_sdk_am64x_09_01_00_41\source\kernel\nortos\dpl\r5\boot_armv7r_asm.S, 

I saw in assembly code it initialize the 7 modes. IRQ, FIQ, USER, SYSTEM ABORT and so on 

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My question,

1.  what is the purpose of go into each mode and initialize all that, is that redundant if we konw, we never use that mode in SBL? 


2. In SBL, actually, we only need system mode.   After jumping to application, application assembly will also set 7 modes  right??

3. can we delete the other 6 modes, since, it is never used, before jump to   application main. 

Thanks.