[U-Boot-Users] Re garding EEPROM Boot
Hai, We have designed MPC8548 based AMC card. We are using u-boot-1.2.0 and it was up. Now we plan to boot the uboot in the EEPROM without using FLASH. Is it possible to boot the uboot in the EEPROM ?. We are using AT24C64C EEPROM(64KB) and it was configured as Extended I2C addressing mode.
Thanks and Regards Sivaji
We have designed MPC8548 based AMC card. We are using u-boot-1.2.0 and it was up. Now we plan to boot the uboot in the EEPROM without using FLASH. Is it possible to boot the uboot in the EEPROM ?. We are using AT24C64C EEPROM(64KB) and it was configured as Extended I2C addressing mode.
Its not quite clear from your comment above; * you've designed an 8548-based board * you've managed to boot it from Flash * now you want to boot from EEPROM
Re-read your data sheet; it is a 64k*bits* EEPROM, or an 8KB memory. You're not going to fit much code in that.
If the 8548 is like the 8349, the purpose of the EEPROM is as a boot-sequencer, i.e., it can be used to program registers in the processor memory map.
If you don't want to have Flash on the card, and the card is a peripheral (which an AMC card is), then you can probably have the processor boot with the core disabled, and use something like the PCI/PCIe interface to boot the processor. You'd have to re-read the manual; the 8349 can boot with the e300 core disabled, have a host copy memory into DDR RAM, and then enable the core to boot from this data.
Cheers, Dave
On 12/12/07, sivaji rameshmrm@gmail.com wrote:
Hai, We have designed MPC8548 based AMC card. We are using u-boot-1.2.0 and it was up. Now we plan to boot the uboot in the EEPROM without using FLASH. Is it possible to boot the uboot in the EEPROM ?. We are using AT24C64C EEPROM(64KB) and it was configured as Extended I2C addressing mode.
In addition to David's comments about the EEPROM being only 8K, I'm doubtful that u-boot on the 8548 can fit even in 64k. The typical build makes it 512k, though I think the actual code size is closer to 150K. I think 8k would require some sort of magic.
IIRC, the EEPROM can contain a configuration sequence, and then a data blob to copy somewhere, which is then executed. If you want that to be u-boot, you'll need a bigger EEPROM. Otherwise, you need to write a boot loader. Is there a reason you don't want to boot from Flash? I'm not familiar with that use case.
Andy
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Andy Fleming -
David Hawkins -
sivaji