u-boot/board/netstal/hcu4
Stefan Roese bbeff30cbd ppc4xx: Remove superfluous dram_init() call or replace it by initdram()
Historically the 405 U-Boot port had a dram_init() call in early init
stage. This function was still called from start.S and most of the time
coded in assembler. This is not needed anymore (since a long time) and
boards should implement the common initdram() function in C instead.

This patch now removed the dram_init() call from start.S and removes the
empty implementations that are scattered through most of the 405 board
ports. Some older board ports really implement this dram_init() though.
These are:

csb272
csb472
ERIC
EXBITGEN
W7OLMC
W7OLMG

I changed those boards to call this assembler dram_init() function now
from their board specific initdram() instead. This *should* work, but please
test again on those platforms. And it is perhaps a good idea that those
boards use some common 405 SDRAM initialization code from cpu/ppc4xx at
some time. So further patches welcome here.

Signed-off-by: Stefan Roese <sr@denx.de>
2008-06-03 20:22:19 +02:00
..
config.mk ppc4xx: Netstal HCU4 board. Added POST. Various fixes 2008-01-17 13:49:51 +01:00
hcu4.c ppc4xx: Remove superfluous dram_init() call or replace it by initdram() 2008-06-03 20:22:19 +02:00
Makefile ppc4xx: HCU4/5. Use FLASH_CFI_LEGACY 2008-03-15 07:25:50 +01:00
README.txt Add PPC4xx-HCU4 and HCU5 boards: READMEs 2007-08-10 09:09:19 +02:00
u-boot.lds Big white-space cleanup. 2008-05-21 00:14:08 +02:00

HCU4 Configuration Details

Memory Bank 0 -- Flash chip
---------------------------

0xfff00000 - 0xffffffff

The flash chip is really only 512Kbytes, but the high address bit of
the 1Meg region is ignored, so the flash is replicated through the
region. Thus, this is consistent with a flash base address 0xfff80000.

The placement at the end is to be consistent with reset behavior,
where the processor itself initially uses this bus to load the branch
vector and start running.

On-Chip Memory
--------------

0xf4000000 - 0xf4000fff

The 405GPr includes a 4K on-chip memory that can be placed however
software chooses. I choose to place the memory at this address, to
keep it out of the cachable areas.


Internal Peripherals
--------------------

0xef600300 - 0xef6008ff

These are scattered various peripherals internal to the PPC405GPr
chip.

Chip-Select 2: Flash Memory
---------------------------

0x70000000

Chip-Select 3: CAN Interface
----------------------------
0x7800000


Chip-Select 4: IMC-bus standard
-------------------------------

Our IO-Bus (slow version)


Chip-Select 5: IMC-bus fast (inactive)
--------------------------------------

Our IO-Bus (fast, but not yet use)


Memory Bank 1 -- SDRAM
-------------------------------------

0x00000000 - 0x1ffffff   # Default 32 MB