From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Tyser Date: Tue, 19 Oct 2010 13:39:41 -0500 Subject: [U-Boot] commit "powerpc: Remove warm reset entry point" does not work on mpc83xx In-Reply-To: References: <1287503471.28856.13840.camel@petert> Message-ID: <1287513581.28856.14110.camel@petert> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de > > > It seems like my board uses the warm start vector at all times. > > > Padding with 4 nop's after the _start symbol fixes the problem. > > > It might be due to a somewhat peculiar reset design but I cannot > > > understand > > > why. Does this work for everyone else using 83xx? > > > > Odd... I don't have an 83xx board to test on unfortunately. Nothing > > jumps out as being obviously wrong in the assembly: > > The difference is that I suspect execution starts at 0xXXXXXX110 rather > than 0xXXXXXX100. BTW, I have my reset vector at 0x0 > > What causes a warm reset? My understanding is that a warm reset on the 8xxx CPUs isn't really a hardware reset - its just when code explicitly jumps to the warm reset entry point. For example, this board used to jump to _start_warm when "reset" was ran in U-Boot: http://git.denx.de/?p=u-boot.git;a=commitdiff;h=3792d7436e2bf881b6abdede5a481a62b5dedd55 During normal use I thought that the reset entry point was always 0xXXXXX100 and a warm reset would never occur. What is the power on reset process like on your board? Best, Peter