[U-Boot-Users] Question about MPC8272 HRCW

Yuli Barcohen yuli at arabellasw.com
Tue Jun 21 23:04:29 CEST 2005

>>>>> Raymond Yang writes:

    Raymond> Still have questions, thanks ahead!

    Raymond> According to DATASHEET

    Raymond> "BMS -

    Raymond> Boot memory space. Defines the initial value for
    Raymond> BR0[BA]. There are two possible bootmemory regions, HIMEM
    Raymond> and LOMEM 0 0xFE00_0000 -- 0xFFFF_FFFF 1 0x0000_0000 --
    Raymond> 0x1FFF_FFFF "

    Raymond> 1) So if let BMS=0,
    Raymond> - Does this mean the BR0[BA] have the exact address
    Raymond> of 0xFE00_00000

Immediately after reset - yes, this will be BR0 value. Then, in your
code, you can set it to whatever you wish.

    Raymond> or
    Raymond> - Does this mean the BR0[BA] could be one of the
    Raymond> address between range 0XFE00_00000 and 0xFFFF_FFFFF, if
    Raymond> this is the case, so how can i determine the specific value
    Raymond> of BR0[BA]?

    Raymond> 2) With BMS=0 and CIP=0

    Raymond> According to the datasheet,

    Raymond> BR0[BA] = 0xFE00_0000 (Right?)  START_VECTOR = 0xFFF0_0100


    Raymond> The span is START_VECTOR-BR0[BA] = 0xFFF0_0100 -
    Raymond> 0xFE00_0000 = 0x1F00100 > 16M, So if my flash is 8M bytes,
    Raymond> i can't use this configuration, right?

Wrong, read again. You will see your flash in the last 8MB
(FF800000-FFFFFFFF). In fact, you will see it repeating itself four
times (FE000000 means 32MB address space).

    Raymond> 3) I pull-down the RSTCONF, it doesn't work, only with
    Raymond> BDI2000 attached and config-file from BDI2000 (RSTCONF up
    Raymond> of cuz), U-BOOT can start correctly. I.e.

For MONITOR_BASE=TEXT_ADDR=0xFFF00000 you need
CFG_FLASH_BASE=0xFF800000. Check BDI initialisations and set the HRCW to
get the same values.

 Yuli Barcohen       | Phone +972-9-765-1788 |  Software Project Leader
 yuli at arabellasw.com | Fax   +972-9-765-7494 | Arabella Software, Israel

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