From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Wozniak Date: Tue, 07 Jun 2005 12:38:01 -0400 Subject: [U-Boot-Users] PPC440GX reset command doesn't work In-Reply-To: <42A5B765.8010304@mc.com> References: <42A5B765.8010304@mc.com> Message-ID: <42A5CD69.7040800@mc.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Andrew Wozniak wrote: > We have a custom PPC440GX board running a ported version of U-Boot based > on the OCOTEA codebase. Most U-Boot commands are working - life is good. > > Except for the 'reset' command. The do_reset() source code at > cpu/ppc4xx/cpu.c appears to be the function for doing the reset via the > PPC "debug control register". The PPC manual shows that a cpu reset is > possible thru this register, but I'm a PPC assembly newbee and need to > figure it out the macros in the cpu.c source code. > > Just wondering if anyone else with a PPC440 target had any special > modifications to make 'reset' work. Ok, understand the assembly macro (except for the ::: "r3"). Must have something to do with do_reset args? Anyway, it appears that a PPC "system reset" does not work as implemented via DBCR0 value 0x30000000. If I change the value to 0x20000000 to do a "chip reset", the U-Boot 'reset' command works! Is this an appropriate solution or might our hardware design have a flaw? Thanks for all suggestions. > Thank you.