On 29 October 2017 at 19:24, Kevin <1728...@bugs.launchpad.net> wrote: > I try to run an emulation with qemu-system-arm under a cpu cortex-m3 but > any execution under the processor result by a segmentation fault. > > My command is : qemu-system-arm -m 256 -M versatilepb -cpu cortex-m3 > -kernel ~/qemu/wheezy/vmlinuz-3.2.0-4-versatile -initrd > ~/qemu/wheezy/initrd.img-3.2.0-4-versatile -hda ~/qemu/wheezy/hda.img > -append 'root=/dev/sda1'
This command line is never going to work, for multiple reasons. Unfortunately QEMU currently doesn't do a good job of identifying option combinations which we know are wrong (like -cpu cortex-m3 with -M versatilepb) and printing an error message. The major problem here is that the cortex-m3 is a microcontroller, which is significantly different from the 'A-profile' devices that Linux runs on. It has no MMU and usually 16MB of RAM or less: why are you trying to run Linux on it? This will never work. Secondly, the "versatilepb" board is not a board which you can use a Cortex-M3 with -- it's only intended to work with certain CPUs, mainly the arm926. Thirdly, that looks like a prebuilt versatile kernel image -- it probably won't work with a random CPU that's not the one the versatile has, and it *definitely* won't work with the M3. Basic rule of thumb for QEMU ARM boards -- don't try to specify "-cpu" unless you have documentation that specifically tells you to. You're much more likely to create something that's just a broken config that guest software can't handle. This is always true for the Cortex-M3 -- unless the board is intended to work with the M3 and is creating the correct interrupt controller, you'll just end up with a broken model. If you need to use the Cortex-M3 then use one of the boards which works with it -- lm3s6965evb, lm3s811evb, mps2-an385, mps2-an511, or netduino2. You'll also need to run guest code which is actually built for the board you're using and for the Cortex-M3 (likely some kind of RTOS, or bare metal code.) The MPS2 boards have the most RAM, but they're only in recent QEMU versions. thanks -- PMM
