On Mon, 3 Apr 2017, Stuart Longland wrote: > On 03/04/17 07:41, Nicolas Pitre wrote: > >> No PTYs seems like a big limitation. This means no sshd? > > Again, my ultimate system target is in the sub-megabyte of RAM. I > > really doubt you'll be able to fit an SSH server in there even if PTYs > > were supported, unless sshd (or dropbear) can be made really tiny. > > Otherwise you most probably have sufficient resources to run the regular > > TTY code. > > Are we talking small microcontrollers here? The smallest machine in > terms of RAM I ever recall running Linux on was a 386SX/25 MHz with 4MB > RAM, and that had a MMU. Not to repeat what I've said already, I invite you to have a look at https://lkml.org/lkml/2017/3/24/634 > I recall Slackware requiring that you booted with a mounted floppy (no > ramdisk) and possibly even required that you had a second floppy drive > formatted as swap so you'd be able to get through the install without > oomkiller knocking on your door. Did the oom killer even exist in those days? I don't remember. All I remember is the stack of 73 flopies or so to install Slackware... and of course floppy #68 would have developed a bad sector preventing you from completing the installation. > Sub-megabyte system support is a noble goal, but I'm wondering how > practical such systems would be, and whether an embedded real-time > kernel might be a better choice than Linux on such systems. Obviously, you need to leave the idea of a _distribution_ behind. If you think of a single user app, and a kernel that only provides those syscalls used by that app, and the minimal subset of kernel services that such an app require, then nothing prevents such and app/kernel from using the actual Linux API. And that's where you get a big advantage over other RTOSes. See the link above for the full rationale. Nicolas -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
