[U-Boot-Users] why the "rm der" instructions before and after erase flash?

[Robert P. J. Day]

  i was just about to take my first shot at building and flashing
u-boot-1.1.2 to an RPXlite_DW board (well, not *exactly* that board
but close enough to at least get u-boot up and running).

  i'm using an abatron BDI2000, and have *lots* of experience flashing
a planet core loader to (in our case) 0xfc000000, the low flash
address.

  the only thing i'm unsure of in the instructions are the two
commands:

  rm der 0x2006000f
  ... erase and flash ...
  rm der 0x2002000f

assuming this means modify debug enable register, what does the above
represent?  i've flashed the PC loader a zillion times without ever
having to modify this register.  is this something i'd only need with
u-boot?

  thanks.

rday