[U-Boot-Users] PowerPC: Relation between HRCW(BMS) and BDI2000 [TARGET] BOOTADDR, [FLASH] <flash_base>

Wolfgang Denk wd at denx.de
Thu Mar 31 18:00:24 CEST 2005

In message <OFA314A9CB.8C2BEC65-ON48256FD5.002C0970 at uk.marconicomms.com> you wrote:
> would like to find out if HRCW(BMS) is tightly coupled to the flash base

No, not at all. The flash  base  is  completely  arbitrary  on  these

> and bootaddress defined in bdi2000 configuration file. If my board has 4

Yes, the boot address in the BDI config file will  be  0xFFF00100  in
one case and 0x00000100 in the other one.

> flash chips with 2MB per chip, should I have something like this with
> relation to HRCW(BMS)?
> HRCW(BMS) = 0 to 0x01FF_FFFF:
> BOOTADDR = 0x100

This will work.

> erase 0 CHIP
> erase 0x200000 CHIP
> erase 0x400000 CHIP
> erase 0x800000 CHIP

This is probably wrong.  Most  probably  your  flash  chips  are  not
attached  to  4  differrent  chip  selects, but to one (using them in

> uboot: TEXT_BASE = 0

This is definitely wrong. RAM has to be mapped at address 0x0000,  so
you cannot map flash there, too.

> versus:
> HRCW(BMS) = 0xFE00_0000 to 0xFFFF_FFFF:
> BOOTADDR = 0xFFF00100

This will work.

> erase 0xFF800000 CHIP
> erase 0xFFA00000 CHIP
> erase 0xFFC00000 CHIP
> erase 0xFFE00000 CHIP

This is probably wrong.  See above.

> uboot: TEXT_BASE = 0xFFF0 0000

This might work.

>       If I use the second configuration with BMS 0xFE00_0000:0xFFFF_FFFF,
> my u-boot image is loaded to the end of the flash region and the size of my
> u-boot image is limited to (0xFFFF_FFFF - 0xFFF0_0000 = 1MB) while if I use

This is  more  than  enough.  At  the  moment  I  know  only  of  one
configuration where U-Boot exceeds 256 kB.

> BMS 0x0:0x01FF_FFFF, the size of the u-boot is not limited?

Don't worry about U-Boot size. 1 MB will be more than enough for  the
next 2 years or so :-)

Best regards,

Wolfgang Denk

Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Drawing on my fine command of language, I said nothing.

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