[U-Boot-Users] mpc8272 Bat Issue

Aldo Sebastiani ( ElsagDatamat Spa ) aldo.lab at gmail.com
Mon Mar 19 12:32:56 CET 2007

Hi all,

in the file cpu/mpc8260/Start.S where the boot clear bat registers:

	/* clear all BAT's						*/
  556 	/*--------------------------------------------------------------*/
  558 	li	r0, 0
  559 	mtspr	DBAT0U, r0
  560 	mtspr	DBAT0L, r0
  561 	mtspr	DBAT1U, r0
  562 	mtspr	DBAT1L, r0
  563 	mtspr	DBAT2U, r0
  564 	mtspr	DBAT2L, r0
  565 	mtspr	DBAT3U, r0
  566 	mtspr	DBAT3L, r0
  567 	mtspr	IBAT0U, r0
  568 	mtspr	IBAT0L, r0
  569 	mtspr	IBAT1U, r0
  570 	mtspr	IBAT1L, r0
  571 	mtspr	IBAT2U, r0
  572 	mtspr	IBAT2L, r0
  573 	mtspr	IBAT3U, r0
  574 	mtspr	IBAT3L, r0
  575 	SYNC

there is a lack for mpc8272 and 8280.

Infact mpc8272 needs to reset all eight bat registers and not only the
first four bat ( as for 8260) because 8272 and 8280 have G2_LE core
instead fo G2.
If you don't fix this kind of setting in uboot you can face
instability for OS that don't reset all bat registers before enabling
I discovered this because I launched my proprietary OS that didn't
reset bat register contrarily what linux do.
If someone is interested to patch I can provide it, that is based on
PVR reading

Aldo Sebastiani
Alessandro Casale

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