[U-Boot-Users] Question about MPC8272 HRCW
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> 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.size)
Wolfgang> or even
Wolfgang> #define CFG_FLASH_BASE (0-flash_info.size-flash_info.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
More information about the U-Boot