[U-Boot-Users] Question about MPC8272 HRCW

Yuli Barcohen yuli at arabellasw.com
Wed Jun 22 11:53:15 CEST 2005

>>>>> Wolfgang Denk writes:

    Raymond> 0xFE00_0000 = 0x1F00100 > 16M, So if my flash is 8M bytes,
    Raymond> i can't use this configuration, right?

    Yuli> Wrong, read again. You will see your flash in the last 8MB
    Yuli> (FF800000-FFFFFFFF). In fact, you will see it repeating itself
    Yuli> four

    Yuli> For MONITOR_BASE=TEXT_ADDR=0xFFF00000 you need
    Yuli> CFG_FLASH_BASE=0xFF800000. Check BDI initialisations and set
    Yuli> the HRCW to

    Wolfgang> Actually I think that using "CFG_FLASH_BASE=0xFF800000" or
    Wolfgang> similar for a high-boot configuration is not optimal, as
    Wolfgang> it does not adjust automatically for varying flash sizes.

Using high-boot configuration on boards with flashes bigger than 1MB is
not optimal IMHO because it creates "hole" in the flash. I personally
can't see any reason to configure such boards for high-boot. I agree
that use of hard-coded values is inconvenient for varying flash sizes.

    Wolfgang> Usually I use something like

    Wolfgang> 	#define CFG_FLASH_BASE (0-flash_info[0].size)

    Wolfgang> or even

    Wolfgang> 	#define CFG_FLASH_BASE (0-flash_info[0].size-flash_info[1].size)

    Wolfgang> in such cases.

    Wolfgang> Just an idea....

The problem is that you usually have to specify BR0_PRELIM/OR0_PRELIM
which can't refer to variables like flash_info. You can initialise chip
selects in the flash driver if you write board-specific driver but if
you use common driver (CFI) things are more complicated.

 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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