> I have been trying to write my own UFS-like filesystem > implementation for fun. I had read somewhere that UFS was developed in > user space (correct me if I'm wrong on that one) and then moved over > to kernel-space. I was wondering if there are any existing facilities > in the kernel source tree that would allow me to develop an fs in user > space easily or with a little tweaking? As of right now, I have to > develop, compile, panic, reboot, debug etc. which is frustrating and > time consuming.
A stub FS that directs all vfs calls to userland would be a handy thing.... Similarly a stub disk -- one should be able to debug support for Petabyte size disk without having to buy one. As for shortening the compile/debug/panic/reboot cycle, you can use qemu. Once a guest os is installed on a disk-image, you can do this: # qemu -s disk-image # cd /usr/obj/usr/src/sys/<KERNEL> # gdb kernel.debug (gdb) target remote localhost:1234 That is it! No need to set up serial console or anything. I haven't tried this but I guess this should work: If you make the FS module a kernel module, and use qemu's snapshot feature, after a crash you can reload from your image right before FS module loading and go from there. Now with a kernel module `kqemu', qemu runs approx twice as slow as real h/w for usercode (as opposed to about 25 times slower without kqemu). _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
