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. ----------------------------------------------------------------------------------------------------------------------- _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot