Hello,
2008/8/8 thaoth thaoth@cybersoft-vn.com:
I have questions about uboot below:
- 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?
- 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@nigauri.org # Yoshihiro Shimoda shimoda.yoshihiro@renesas.com
I got a toolchain at http://www.superh-linux.org/archive/bsp/sh7721_se/toolchain_sh3_gcc4.2.tar.g... 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.
- 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.
- 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