Alex Zeffertt wrote:
Hi list,
I would like to boot my MPC8272ADS board from the base of flash memory. By default the BCSR delivers a fixed HRCW which tells the CPU to boot from 0xff700000. But there is a jumper on the board which allows you to specify that the CPU should retrieve the HRCW from flash.
In an attempt to get it to boot from 0x0 I tried the following:
Moved jumper JP9 from "BCSR" to "MEMORY" to tell the CPU to get its HRCW from flash rather than the BCSR.
Set TEXT_BASE in config.mk to 0x0
define CFG_HRCW_MASTER in MPC8260ADS.h to be the value normally delivered by the BCSR or'd with (HRCW_CIP | HRCW_BMS). This should move the reset vector from 0xfff00100 to 0x100 and cause the flash to be mapped from 0x0 to 0x01ffffff.
Unfortunately this didn't work.
Has anybody else managed to get the MPC8272ADS to boot WITHOUT using the BCSR to deliver the HRCW?
Regards,
Alex
Hi Alex,
I did this for the PQ2FADS board, which should be very similar to the MPC8260ADS board. Check out the "bootlow" configuration for PQ2FADS.
I cannot give you specific advice, but I would review each and every bit in the HRCW (step #3 doesn't sound thorough enough). Ahhh, looking at my patch email (below), the IMMR that your board defaults to may not be a happy choice.
References: ----------- Gmane archive, includes the patch Wolfgang applied. http://search.gmane.org/?query=PATCH%3A+add+low-boot+configuration+to+MPC8260ADS+family+of+boards+&email=&group=&sort=relevance&DEFAULTOP=and&xP=patch.add.low.boot.configuration.mpc8260ads.family.boards.&xFILTERS=Gu-boot---A
Sourceforge's email list (no attachments): http://sourceforge.net/mailarchive/message.php?msg_id=9992822
Follow-up posting: http://article.gmane.org/gmane.comp.boot-loaders.u-boot/17917
gvb