Hi Manu,
On 01/06/11 14:53, mano r wrote:
We are in the process of porting Linux to ARM922 based custom board. As an initial level we would like to start with an MMU-less OS. We understand uClinux best suits our requirement as uClinux is for MMU-less MPUs. We are very much beginner with Linux and uClinux. We have some doubt regarding uClinux. 1. In folder ./uClinux-dist/linux 2.6.x/arch/ we didn't find any armnommu folder, while there is a seperate folder named armnommu in /uClinux-dist/linux 2.4.x/arch. So do linux 2.6.x support MMU-less MPU?
Linux-2.6.x kernels do support non-MMU ARM parts. All the code for that is also in arch/arm. It is just based on whether CONFIG_MMU is enabled or not.
2. We found KS8695 in linux 2.6.x is ARM922T based board and we would like to use configuration of KS8695 for porting to our custom board. So Is it possible to port an MMU-less uClinux using KS8695 configuration or does KS8695 only support MMU based OS?
Currently KS8695 only supports having the MMU enabled. It would take some work but you could configure/build for this with the MMU disabled.
3. We are able to compile successfully the KS8695 based uClinux with the "MMU-based Paged Memory Management Support" under System type menu in Linux Kernel Configuration OFF. Also we have selected Disable I-Cache (I-bit)and Disable D-Cache (C-bit) options. The system.map file is attached for reference. Since we don't have a KS8695 EVB, we don't know whether the zImage generated with MMU OFF will work or not.
If the processor you are porting to actually has an MMU I wouldn't bother going to uClinux (non-MMU) first. Go strait into building it with MMU enabled. If you really want uClinux and you don't have an 8695 board then there may not be too much value heading down that path. Of course use it as a reference for what an ARM922T needs enabled in terms of kernel configuration. But why bother spending time debugging it, just debug the target board you are porting for. Regards Greg ------------------------------------------------------------------------ Greg Ungerer -- Principal Engineer EMAIL: g...@snapgear.com SnapGear Group, McAfee PHONE: +61 7 3435 2888 8 Gardner Close FAX: +61 7 3217 5323 Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com _______________________________________________ uClinux-dev mailing list uClinux-dev@uclinux.org http://mailman.uclinux.org/mailman/listinfo/uclinux-dev This message was resent by uclinux-dev@uclinux.org To unsubscribe see: http://mailman.uclinux.org/mailman/options/uclinux-dev
