From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 29 Nov 1999 23:46:54 +0000 From: "Robin O'Leary" To: linuxppc-embedded@lists.linuxppc.org Subject: 860T cold boot Message-ID: <19991129234653.A1270@mail.ro.nu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: I have been following the linuxppc-embedded discussions for some time while pottering with an i-Mac and the Bright Star ipEngine, in preparation for our new 860T-based hardware to be designed and built. It had been so easy to use both these systems, I was unprepared for the ordeal involved in getting the 860T hardware going without the assistance of a boot-loader. Using the (rather unreliable) SDS SingleStep development kit and BDM cable, I can address all the CPU memory-mapped registers, set up the SIU, load zImages into RAM or flash and make them run. I can write simple programs that waggle I/O ports and generally test that the hardware is present and correct. But when I try to run a zImage it all goes wrong. The debugger doesn't seem able to insert working breakpoints after the first ``rfi'' so I can't tell exactly what's the matter, but inevitably it crashes with some sort of exception, usually with PC=0x1100 (TLB miss exception) where there is no code. I've tried booting from RAM and flash, with code, RAM and registers at various addresses, with various kernels. I'm sure that the basics are correct and as nobody else seems to be talking about problems with this low-level stuff, either you're all using proprietary boot loaders or I'm missing something obvious (or it's a hardware problem:-). I currently set up 25 registers plus the UPM table with values derived initially from Motorola's hopeless mcuinit tool, later much tinkered with by reference to the 860UM/AD manual. I'm sure that's all I should need to get it going. Am I right? If anybody has a working set of initialisation instructions that they could share, or even just a register dump of how their boot-loader leaves things set, I should be most grateful. Robin O'Leary. -- email: roleary@equiinet.com Equiinet Ltd., Innovation Centre, Singleton Park, Tel.: +44 1792 540008 Swansea SA2 8PP, Wales, U.K. 51.6101N 3.9831W ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/