Warm reboot on 826x targets

Eugene Surovegin ebs at ebshome.net
Wed Apr 13 04:31:31 EST 2005


On Tue, Apr 12, 2005 at 11:14:35AM -0700, Paul Gortmaker wrote:
> I've been trying to get a WRS 8265 to do a warm reboot, and found some
> things that I am wondering about.
> 
> Firstly, is anyone having success on having "reboot" restart the machine
> on a similar platform?
> 
> Secondly, the default BOOTROM_RESTART_ADDR is 0x40000104 (sbc82xx.h) and I
> was wondering if this matches any platforms out there.  On this board, the
> place where U-Boot lives is 0xFFF00104 -- and I've verified this by typing
> "g fff00104" at the U-Boot prompt which causes U-Boot to simply restart.
> 
> I've changed the value in sbc82xx.h and now at the reboot, instead of a
> register dump, it simply hangs.  Looking at m8260_gorom (in kernel/head.S)
> it clears the MSR_EE (ext int. enable) bit in the MSR before jumping --
> but I was wondering if there are other bits in MSR that need to be
> cleared; e.g. instruction relocation enable and data relocation enable
> (MSR_IR and MSR_DR). The register bits are on p76 of MPCFPE32B.pdf from
> Freescale.
> 
> I guess if somebody even said "it works for me" then I'd have a better
> feeling thinking that what is done to the MSR currently is sufficient.

I don't have any problems using reboot() on 8248 based board. 
Kernel.org-based 2.4.29 tree.

I have U-Boot at 0xfe00'0000, and I use 0xfe00'0104 as a second 
parameter for m8260_gorom. Also make sure that first parameter is also 
correct:

	m8260_gorom(__pa(__res), 0xfe000104);

-- 
Eugene




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