topic question about P2020 U-boot TLB setting in P-Series

question about P2020 U-boot TLB setting

hyoungkikim — Tue, 02 Feb 2016 09:28:01 GMT

i have a difficult time to configure u-boot to a new board

( i am not good at english ^^)

i am porting u-boot to a new board which is based on P2020RDB-PC

the board has MRAM device and external uart chips which was connected to eLBC

i configured LAWS and related registers

but i have no clue about TLB

in u-boot there is a tlb.c in P2020RDB board related files

and in that file tbl_table is defined

is this necessary to include new device into that table ?

if so, how ?

just copy one entry to new one and modify just address ?

and what about kernel ? where do i configure TLB ?

thanks in advnace

Re: question about P2020 U-boot TLB setting

bpe — Tue, 02 Feb 2016 14:26:59 GMT

>is this necessary to include new device into that table ?

>if so, how ?

[Platon] If you need to do anything with your peripherals in u-Boot

environment, then yes, you have to set a TLB for them. Some of our

development systems have board-level control registers connected to

the local bus, see how TLBs are defined for them, do the same. You take a

look how macros PIXIS_BASE, PIXIS_BASE_PHYS are used in in

/board/freescale/p1022ds/tlb.c for instance.

If your peripherals are to be used in Linux only, then it is OK not

to setup a TLB for them (LAW is still necessary).

>and what about kernel ? where do i configure TLB ?

[Platon] Linux kernel creates a mapping for a peripheral when it's

driver calls ioremap().

Have a great day,
Platon

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Re: question about P2020 U-boot TLB setting

hyoungkikim — Wed, 03 Feb 2016 07:21:29 GMT

thank you it is really of great help