Le 27/09/2010 08:36, Prafulla Wadaskar a écrit :
-----Original Message----- From: Albert ARIBAUD [mailto:albert.aribaud@free.fr] Sent: Monday, September 27, 2010 12:05 PM To: Prafulla Wadaskar Cc: u-boot@lists.denx.de; Ashish Karkare; Prabhanjan Sarnaik Subject: Re: [U-Boot] [PATCH V2 1/2] [NEXT] orion5x: fix relocation-incompatible code
Le 27/09/2010 07:52, Prafulla Wadaskar a écrit :
- NOTES:
- in order to avoid losing access to BOOTCS when
disabling window 7,
- first configure window 6 for BOOTCS, then configure
window 7 for BOOTCS,
- then configure windows 6 for its own target.
+/* Disable window 6, configure it for FLASH, enable it. */
- writel(0,&winregs[6].ctrl);
- writel(ORION5X_ADR_BOOTROM,&winregs[6].base);
- writel(ORION5X_CPU_WIN_CTRL_DATA(ORION5X_SZ_BOOTROM,
ORION5X_TARGET_DEVICE, ORION5X_ATTR_BOOTROM, ORION5X_WIN_ENABLE),&winregs[6].ctrl);
- writel(ORION5X_ADR_DEV_CS2,&winregs[6].base);
- /* Window 7: BOOT Memory address space */
+/* Disable window 7, configure it for FLASH, enable it. */
- writel(0,&winregs[7].ctrl);
- writel(ORION5X_ADR_BOOTROM,&winregs[7].base); writel(ORION5X_CPU_WIN_CTRL_DATA(ORION5X_SZ_BOOTROM, ORION5X_TARGET_DEVICE, ORION5X_ATTR_BOOTROM, ORION5X_WIN_ENABLE),&winregs[7].ctrl);
- writel(ORION5X_ADR_BOOTROM,&winregs[7].base);
+/* Disable window 6, configure it for its intended target, enable it. */
- writel(0,&winregs[6].ctrl);
This conflicts with above win6 configuration. If done purposely then pls provide comments.
Regards.. Prafulla . .
Er... The comment *is* there, right before the sequence.
Why do you need to configure win6 twice?
Because if I don't set a window beside 7 to access BOOTCS, then reconfiguring window 7 (BOOTCs, i.e. FLASH) leaves the system with no access to BOOT CS thus no access to FLASH thus no way to continue executing this code, which runs from FLASH.
Thus I chose window 6 (I could have chosen any other, of course) and set it up for flash so that code can still run while reconfiguring window 7; then window 6 must, and can safely, be reconfigured for its own target.
(This issue of FLASH access does not happen on designs where boot is from NAND, of course; but the fix would be harmless even on these)
Regards.. Prafulla . .
Amicalement,