Porting u-boot, using emulator, run from SDRAM
Hello,
we try to get u-boot running on an Infineon Switch Evaluation Board (MXU rev.B, MPC850). There is a VxWorks image in FLASH which is starting and running correct.
We would like to stop the start of the VxWorks image with our Lauterbach Emulator and then laod the u-boot bootloader into SDRAM and start u-boot. This is already done (our script for Lauterbach works).
We started with the tqm850L configuration (u-boot 0.2.0), successively changing/ commenting things. We already managed to modify the u-boot code, so that we get to the u-boot command prompt, where we can enter commands. Unfortunately we just hacked around and didn't really understand well how the u-boot code could be adapted to our board. Commenting out some RAM/FLASH size check routines and clock discovery routines leads to not properly filled structures.
- Is there a simple #define switch to support u-boot running from SDRAM, loaded into RAM with an emulator? - I think this would be a nice feature in order to port the u-boot code to a new board.
- E.g. reading manufacturer ID of FLASH doesn't work at all. We also didn't manage to read this ID with issuing FLASH writes/reads from Emulator. But using the VxWorks boot prompt commands it works.
Maybe someone has some suggestions on how to go on.
Thanks,
Gerhard
Quoted 4 lines · In message <[email protected]> you wrote:
we try to get u-boot running on an Infineon Switch Evaluation Board (MXU rev.B, MPC850). There is a VxWorks image in FLASH which is starting and running correct.
make a backup, erase it, and install U-Boot in it's place.
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We would like to stop the start of the VxWorks image with our Lauterbach Emulator and then laod the u-boot bootloader into SDRAM and start u-boot. This is already done (our script for Lauterbach works).
If you want to use U-Boot, there is no reason to keep the VxWorks bootloader; U-Boot can boot VxWorks images, too.
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We started with the tqm850L configuration (u-boot 0.2.0), successively changing/ commenting things. We already managed to modify the u-boot code, so that we get to the u-boot command prompt, where we can enter commands. Unfortunately we just hacked around and didn't really understand well how the u-boot code could be adapted to our board.
Then restart from scratch, and do it properly this time.
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Commenting out some RAM/FLASH size check routines and clock discovery routines leads to not properly filled structures.
Among other potential problems.
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- Is there a simple #define switch to support u-boot running from SDRAM, loaded into RAM with an emulator? - I think this would be a nice
No there is not.
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feature in order to port the u-boot code to a new board.
This is a matter of style. I always find it much easier to get things working in the same sequence as they happen in reality. And this means to start it from the boot device as addressed by /CS0, i. e. usually from flash.
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- E.g. reading manufacturer ID of FLASH doesn't work at all. We also didn't manage to read this ID with issuing FLASH writes/reads from Emulator. But using the VxWorks boot prompt commands it works.
Seems your (modified?) version of the flash driver does not atch your hardware. Fix it.
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Maybe someone has some suggestions on how to go on.
As mentioned above: restart from scratch, and do it again properly, step by step. Don't focus on getting a "running system" with command prompt and everything first - solve the problems in the sequence they pop up. The rest will automatically fall in place.
Best regards,
Wolfgang Denk
Signature · 4 lines
Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de Too much of anything, even love, isn't necessarily a good thing. -- Kirk, "The Trouble with Tribbles", stardate 4525.6
Quoted 5 lines · Wolfgang Denk
Quoted 1 line · In message <[email protected]> you wrote:
... There is a VxWorks image in FLASH
make a backup, erase it, and install U-Boot in it's place.
I have to find out how I can do that.
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Quoted 2 lines
commands. Unfortunately we just hacked around and didn't really understand well how the u-boot code could be adapted to our board.
Then restart from scratch, and do it properly this time.
We'll try to do so, but understanding what has to be changed is not easy.
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Quoted 3 lines
- E.g. reading manufacturer ID of FLASH doesn't work at all. We also didn't manage to read this ID with issuing FLASH writes/reads from Emulator. But using the VxWorks boot prompt commands it works.
Seems your (modified?) version of the flash driver does not atch your hardware. Fix it.
Before restarting from scratch I would like to ask more about our FLASH problem (in a separate question).
Thanks for your reply,
Gerhard