readme

U-Boot1.1.2是最为常用的嵌入式系统Bootloader

After following the step of Yoo. Jonghoon and Wolfgang Denk,
I ported u-boot on RPXlite DW version board: RPXlite_DW or LITE_DW.

There are three differences between the Yoo-ported RPXlite and the RPXlite_DW.

Board(in U-BOOT)	version(in EmbeddedPlanet)	CPU	SDRAM	FLASH
RPXlite				RPXlite CW		850	16MB	4MB
RPXlite_DW			RPXlite DW		823e	64MB	16MB

This fireware is specially coded for EmbeddedPlanet Co. Software Development
Platform(RPXlite DW),which has a NEC NL6448BC20-08 LCD panel.

It has the following three features:

1. 64MHz/48MHz system frequence setting options.
The default setting is 48MHz.To get a 64MHz u-boot,just add
'64' in make command,like

make RPXlite_DW_64_config
make all

2. CFG_ENV_IS_IN_FLASH/CFG_ENV_IS_IN_NVRAM

The default environment parameter is stored in FLASH because it is a common choice for
environment parameter.So I make NVRAM as backup parameter storeage.The reason why I
didn't use EEPROM for ENV is that PlanetCore V2.0 use EEPROM as environment parameter
home.Because of the possibility of using two firewares on this board,I didn't
'disturb' EEPROM.To get NVRAM support,you may use the following build command:

make RPXlite_DW_NVRAM_config
make all

3. LCD panel support

To support the Platform better,I added LCD panel(NL6448BC20-08) function.But bewear of
the fact that once you build this support and program it to FLASH,you should make sure
you put workable kernel and ramdisk at the right place in FLASH or through NFS.
Otherwise, you must erase this fireware manually via BDI2000 or ICE tools.So this
function is used for deployment and demo only.Pls look before you leap.

To get a LCD support u-boot,you can do the following:

make RPXlite_DW_LCD_config
make all

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The basic make commands could be:

make RPXlite_DW_config
make RPXlite_DW_64_config
make RPXlite_DW_LCD_config
make RPXlite_DW_NVRAM_config

BTW,you can combine the above features together and get a workable u-boot to meet your need.
For example,to get a 64MHZ && ENV_IS_IN_FLASH && LCD panel support u-boot,you can type:

make RPXlite_DW_NVRAM_64_LCD_config
make all

So other combining make commands could be:

make RPXlite_DW_NVRAM_64_config
make RPXlite_DW_NVRAM_LCD_config
make RPXlite_DW_64_LCD_config

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The boot process by "make RPXlite_DW_config" could be:

U-Boot 1.1.1 (Jun  8 2004 - 11:16:30)

CPU:   PPC823EZTnnB2 at 48 MHz: 16 kB I-Cache 8 kB D-Cache
Board: RPXlite_DW
DRAM:  64 MB
FLASH: 16 MB
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Net:   SCC ETHERNET
u-boot>

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

I'd like to extend my heartfelt gratitute to kind people for helping me work it out.
I would particually thank Wolfgang Denk for his nice help.

Enjoy,

Sam Song, [e-mail]
Institute of Electrical Machinery and Controls
Shanghai University

June 8,2004