On Tue, 17 Aug 2004 13:43:15 +0200, Wolfgang Denk wd@denx.de wrote:
Hey WD, can you explain a bit on how you actually did this? The preboot command copies something from PCI. How / when do you write to the SDRAM over PCI? Did you do this through interrupts? Or was it something else?
In our case this was different. The system is a standard PCI card which sits in a PC. Some software on the PC will initialize the card, holding the processor in reset. It will then upload the U-Boot image into SDRAM, and then release the processor on the card which will boot U-Boot from the location in RAM, which then in turn will load and boot Linux.
My situation is a bit similar as well. I too have a PCI card. However, we do have flash, so I use u-boot to initialize the SDRAM and UART on the board. After this is done, some binary (evenutally, a uImage) is to be loaded and run. How to synchroize these things? How to stop u-boot so that image from the PCI can be transferred? Better would be to interrupt the host, and the driver then signals some userspace program to transfer the image. After this, signal the MV64360 that the binary is loaded, so that u-boot can then continue and transfer execution to the binary / uImage.
Is this too murky?
Amti.
Best regards,
Wolfgang Denk
-- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd@denx.de Quote from the Boss... "I didn't say it was your fault. I said I was going to blame it on you."