TM03%SWTEXAS.BITNET@ricevm1.rice.edu (10/31/90)
After upgrading to 1.5 I noticed in the kernel code that there must be a debugging system for the kernel, but I don't know how to use it. Can someone indicate whether I am correct and tell me how to use(access) the debugging features if there? Oh, I forgot, this is PC Minix. Thanks in advance, tom mccabe tm03@swtexas.bitnet
evans@syd.dit.CSIRO.AU (Bruce.Evans) (11/05/90)
In article <35005@nigel.ee.udel.edu> TM03%SWTEXAS.BITNET@ricevm1.rice.edu writes: >After upgrading to 1.5 I noticed in the kernel code that there must >be a debugging system for the kernel, but I don't know how to use it. >Can someone indicate whether I am correct and tell me how to use(access) >the debugging features if there? Oh, I forgot, this is PC Minix. You start by getting db.tar.Z and half of my 386 kit (bcc.tar.Z, bccbin16.tar.Z and bcclib.tar.Z) from an archive. The debugger is rather primitive but allows stopping and restarting Minix (or DOS) at almost any time, e.g. inside a device driver. It was useful for debugging the 286 and 386 protected mode ports of Minix. Actually, Minix was simple to debug compared with debugging the debugger :-). I recently found a bug in the 386 debugger+Minix. One machine crashed when the debugger exited after being used early. The problem was that the debugger tries to restore the fs and gs registers, and some BIOS's leave these with illegal (real mode) values. Minix needs to load them (with 0) a bit earlier. -- Bruce Evans evans@syd.dit.csiro.au