[U-Boot] Uboot AS Space in MPC85xx Start.S

[Vignesh Kumar B]

Hi,

I am working on the Start.S in the Bootloader code for MPC8572. I find
that At some point of time we say we switch to AS=1 when setting TLB.
After cpu_early_init_f we switch back to AS=0. So we do this to avoid
some mismatch. But when we shift back to AS=0, I want to know what is
there in that Address Space 0. Can some one help me on this. Suppose I
am modifying the code of u-boot into just one function board_init_f
without the previous call then what operations should be done on AS=0
and AS=1.

Let me know.

Actual Code Snippet:

	bl	cpu_init_early_f           ---> This is happening in AS
= 1

	/* switch back to AS = 0 */
	lis	r3,(MSR_CE|MSR_ME|MSR_DE)@h
	ori	r3,r3,(MSR_CE|MSR_ME|MSR_DE)@l
	mtmsr	r3
	isync

	bl	cpu_init_f		---> This is happening in AS = 0
	bl	board_init_f
	isync

My Code :

#AS=1
TLB Mapping
..
..
..
#switch back to AS = 0
	lis	%r3,(MSR_CE|MSR_ME|MSR_DE)@h
	ori	%r3,%r3,(MSR_CE|MSR_ME|MSR_DE)@l
	mtmsr	%r3
	isync

	bl	main		# Jump to main() for board & cpu init

Thanks & Regards,
Vignesh Kumar B





DISCLAIMER:
-----------------------------------------------------------------------------------------------------------------------

The contents of this e-mail and any attachment(s) are confidential and intended for the named recipient(s) only.
It shall not attach any liability on the originator or HCL or its affiliates. Any views or opinions presented in 
this email are solely those of the author and may not necessarily reflect the opinions of HCL or its affiliates.
Any form of reproduction, dissemination, copying, disclosure, modification, distribution and / or publication of 
this message without the prior written consent of the author of this e-mail is strictly prohibited. If you have
received this email in error please delete it and notify the sender immediately. Before opening any mail and 
attachments please check them for viruses and defect.

-----------------------------------------------------------------------------------------------------------------------