CONFIG_MTD_PHYSMAP_START= physical address of NOR FLASH

[Thomas Gleixner]

On Wed, 2005-02-02 at 18:24 +0000, Alex wrote:
> CONFIG_MTD_PHYSMAP_START=0x04000801 (this is higher than RAM !)

1. It never starts on an odd address
2. It's inside the reserved physical address space of RAM

> So (based on the data given to me)
> should I use 0x00000801 as a physical
> start address of my NOR FLASH chip ?
> (i got this info from h/w people in Italy)

See below.

> The initial boot provides the following:
> Memory map:
> /* Chip Select FLASH Normal */
> #define BR0_VAL 0x04000801  /* Offset=0x04000000 PS=16 GPCM Valid=1 */
> #define OR0_VAL     0xFFC00160  /* OK */

The value you are using is the value, which is programmed into the BR0
register of the CPU. 
BRx = Bank Register for chipselect x
ORx = Option Register for chipselect x
The values in those registers define the startaddress, buswitdh, size,
timings for the chipselects. So using those values is definitely not a
good idea. Of course you can decode the values in the registers to get
your real address values. 

I have no datasheet handy, but you should definitely read it :)

tglx