In message <885489B3B89FB6449F93E525DF78777F06453E at srvnt506.ALLOPTIC.COM> you wrote: > why would it be better to use the device driver than via the mmap from user > space?
Reliability, robustnes, clean design, ... Why do we have a separation into kernel and user space at all? > one of my criteria was to make sure no software mistake will cause the > kernel to hang, as > in the case of vxWorks we are running. So, if I implement my access to the Then don't weaken the memory protection of the Unix design. > device > in the device driver, doesn't that means if there are problem with the > device driver > portion, i will cause the kernel to hang? Furthermore, any enhancement to Don't you think that an application process that will write random data to your hardware will have a much higher potential to cause harm than a carefully designed, implementred, reviewed and tested device driver? > driver will require me to reinstall the kernel? whereas if all my user > space > application handles the access to those devices, I can stop the user space > application, > update it with the new application without requiring the system to reboot? You can dynamically load and unload device drivers. Wolfgang Denk -- Software Engineering: Embedded and Realtime Systems, Embedded Linux Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de "Wish not to seem, but to be, the best." - Aeschylus ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
