On 2012-07-31, Freddie Chopin <freddie_cho...@op.pl> wrote: > I was wondering whether it's possible (in a reasonable amount of time) to port > Dropbear to bare-metal platform - one without an OS (like Linux), but with > RTOS > (FreeRTOS) that provides tasks, queues and synchronization (semaphores + > mutexes) + LwIP TCP/IP stack? > > I would require a very minimal implementation of SSH server, without all > possible encryption options (the code/RAM footprint has to be low) and without > all possible features - ideally only simpliest SSH server that can pass > received > strings to other parts of code and transfer strings from code via SSH to > connected client. Of course I'm talking only about command-line interface. > > If Dropbear is not a good option for such task, do you have any other > recommendations?
I've used (non-free) SSL/SSH libraries from Peersec on a platform similar to what you're describing (using an RTOS different than, but similar to, FreeRTS). I haven't looked at dropbear source code in any detail, but I can tell you that porting network servers written to run on a Unix OS to an RTOS environment can be _very_ difficult. The two main problems are that the servers generally expect to be able to 1) Call fork() to create a server process for each incoming connection. 2) Call exit() after a connection is closed with the assumption that all the resources that were allocated will be auto-magically "freed". Coming up with fixes/work-arounds for those two issues alone can be a huge amount of work. -- Grant Edwards grant.b.edwards Yow! Used staples are good at with SOY SAUCE! gmail.com