[U-Boot-Users] [T-Engine] UBoot configuration for T-Engine/SH7727 MS7727CP02 DevKit

[Nobuhiro Iwamatsu]

Hello,

2008/8/8 thaoth <thaoth at cybersoft-vn.com>:

>
> I have questions about uboot below:
> 1. Reallocating address of u-boot in booting process.
> At the booting process, the address 0x80000000 is executed. This is memory
> mapping address of Flash memory. and executable code of T-Monitor will be
> executed.
>
> (1) ROM area memory map
> In ROM, 8M byte(0x80000000-0x807FFFFF)of area is implemented.
> Memory map of ROM area is shown as below.
>
>     0x80000000 +-------------------------------+
>                |      T-Monitor code           |
>                |- - - - - - - - - - - - - - - -|
>                |                               |
>     0x80010000 +-------------------------------+
>                |        ROM Information        |
>     0x80010080 +-------------------------------+
>                |System configuration info      |
>                |     (SYSCONF / DEVCONF)       |
>                |- - - - - - - - - - - - - - - -|
>                |                               |
>     0x80020000 +-------------------------------+
>                |       T-Kernel code           |
>                |                               |
>                +-------------------------------+
>                |                               |
>                |         User area             |
>                |                               |
>     0x80800000 +-------------------------------+
>
> UBoot code will reflash into Flash memory at 0x80000000 address. This is
> Flash Memory just readonly. Will UBoot reallocating (loading) binary code
> into SDRAM at TEXT_BASE address. In T-Engine/Sh7727, this address will be
> 0x8DFC0000 (Beginning address of SDRAM is 0x8C000000). Does UBoot
> automatically reload this code into TEXT_BASE address?

Yes, U-Boot designed working on SDRAM.
In cpu/sh3/start.S, code of U-boot is copied from a flash bulb by memory and
jump in memory.
Because implementation of original U-boot comes to work as for this on memory,
I match the SuperH with this implementation.

>
> Because Boot starting address will begin at Flash memory (0x80000000) and
> T-Monitor (current boot loader) worked at this address. I don't know how
> about UBoot. Does it reload Uboot into SDRAM (TEXT BASE) and run?
>
> 2. This is a great site for working SH with Linux.
> http://www.superh-linux.org/platforms/index.html
> Based on Reference board board/ms7720se, I changed the UBoot configuration
> for T-Engine/SH7727 MS7727CP02 Kit.
>
> Many thanks to authors for your efforts
> # Nobuhiro Iwamatsu <iwamatsu at nigauri.org>
> # Yoshihiro Shimoda <shimoda.yoshihiro at renesas.com>
>
> I got a toolchain at
> http://www.superh-linux.org/archive/bsp/sh7721_se/toolchain_sh3_gcc4.2.tar.gz
> It supported "elf32-sh-linux" target.
> And I also got toolchain from T-Engine forum and it support
> "elf32-sh-tkernel" target.
>
> I don't know UBoot built with toolchain from http://www.superh-linux.org can
> work on T-Engine platform or not?
Sorry , I dont know it.
The tool chain of http://www.superh-linux.org tests only elf32-sh-linux.

>
> 3. Debugging tool for U-Boot development.
> Please tell me how to debug UBoot can work on board. Could you tell me
> debugger tool for this purpose? Now I can reflash UBoot into Flash Memory
> but I don't know how to check UBoot can work on it. Because porting have
> others issues such as serial library, interrupt....
>
> Could you recommend a tool can check it can work?
> Sorry for stupid question.
A developer has many cases to debug with ICE.
When there is not ICE, We write in it at SDRAM with monitor and debug
it on SDRAM.

>
> 4. Serial driver for UBoot on T-Engine/SH7727 board.
> After make sure these configuration are correct setting (SDRAM adress, Flash
> Memory). Next step is serial porting for UBoot.
>
> I think serial is basic peripheral and It can work with a small changes. But
> Maybe I am wrong. Could you recommend the steps I could work on for serial
> porting of UBoot?
>
> T-Engine has a serial library. I don't know how can reuse this library or
> not? :(
>

There is two approach.
1. You delete content of Flash, and it is the method that only U-Boot uses.
   When you use this method, you come to need ICE.
   But this is very simple.

2. You call U-boot like an application from T-monitor, and to use.
   When you use this method, you will not need ICE.
   But you need Implementation serial function used T-monitor's library.


I will ask a specialist in T-engine an opinion.
I will send e-mail it if there is some information.

Many Japanese companies become the long vacation from tomorrow.
Because I am a holiday, an answer is not possible for approximately 2
weeks.

Best regards,
 Nobuhiro
-- 
Nobuhiro Iwamatsu