Commit graph

50 commits

Author SHA1 Message Date
rsc eaea18cb9c PDF at http://am.lcs.mit.edu/~rsc/xv6.pdf
Various changes made while offline.

 + bwrite sector argument is redundant; use b->sector.
 + reformatting of files for nicer PDF page breaks
 + distinguish between locked, unlocked inodes in type signatures
 + change FD_FILE to FD_INODE
 + move userinit (nee proc0init) to proc.c
 + move ROOTDEV to param.h
 + always parenthesize sizeof argument
2007-08-22 06:01:32 +00:00
rsc f1f8dd91bc formatting 2007-08-14 18:42:34 +00:00
rsc 8139713c46 add note 2007-08-10 17:19:15 +00:00
rsc dca5b5ca2e avoid assignments in declarations 2007-08-10 17:17:42 +00:00
rsc b6095304b7 Make cp a magic symbol. 2007-08-10 16:37:27 +00:00
rsc b6dc6187f7 add DPL_USER constant 2007-08-08 09:02:42 +00:00
rsc 7366e042d9 save process name for debugging 2007-08-08 08:38:11 +00:00
rsc e936743429 tweak 2006-09-08 15:34:04 +00:00
rsc cd12eea3c7 make trap fit on one page 2006-09-08 14:29:58 +00:00
rsc 0b75a8e8be no recursive interrupts 2006-09-07 16:53:16 +00:00
rsc 31085bb416 more comments 2006-09-07 14:12:30 +00:00
rsc 0cfc7290e8 wrap long lines 2006-09-06 19:08:14 +00:00
rsc f552738889 no /* */ comments 2006-09-06 17:50:20 +00:00
rsc 9e9bcaf143 standardize various * conventions 2006-09-06 17:27:19 +00:00
rsc a650c606fe spacing fixes: no tabs, 2-space indents (for rtm) 2006-09-06 17:04:06 +00:00
kaashoek a81e02133a a few nits 2006-09-04 12:41:27 +00:00
kaashoek 97c74a3a64 nits 2006-09-03 18:32:58 +00:00
rtm 3b95801add i broke sbrk, fix it 2006-08-29 17:01:40 +00:00
rtm 2b19190c13 clean up stale error checks and panics
delete unused functions
a few comments
2006-08-29 14:45:45 +00:00
kaashoek 74493bf446 kill user process when it generates an unhandled trap (e.g., 13)
fix bug in test code of malloc
2006-08-25 00:43:17 +00:00
kaashoek 8787cd01df chdir
cd in shell
nits in mkdir, ls, etc.
2006-08-19 23:41:34 +00:00
rtm ceb0e42796 proc[0] can sleep(), at least after it gets to main00()
proc[0] calls iget(rootdev, 1) before forking init
2006-08-16 01:56:00 +00:00
rtm 350e63f7a9 no more proc[] entry per cpu for idle loop
each cpu[] has its own gdt and tss
no per-proc gdt or tss, re-write cpu's in scheduler (you win, cliff)
main0() switches to cpu[0].mpstack
2006-08-15 22:18:20 +00:00
rtm 5be0039ce9 interrupts could be recursive since lapic_eoi() called before rti
so fast interrupts overflow the kernel stack
fix: cli() before lapic_eoi()
2006-08-10 22:08:14 +00:00
rtm 8a8be1b8c3 low-level keyboard input (not hooked up to /dev yet)
fix acquire() to cli() *before* incrementing nlock
make T_SYSCALL a trap gate, not an interrupt gate
sadly, various crashes if you hold down a keyboard key...
2006-08-10 02:07:10 +00:00
rtm 0e84a0ec6e fix race in holding() check in acquire()
give cpu1 a TSS and gdt for when it enters scheduler()
and a pseudo proc[] entry for each cpu
cpu0 waits for each other cpu to start up
read() for files
2006-08-08 19:58:06 +00:00
rsc b5f17007f4 standarize on unix-like lowercase struct names 2006-07-17 01:58:13 +00:00
rsc b5ee516575 add uint and standardize on typedefs instead of unsigned 2006-07-17 01:52:13 +00:00
rsc ee9c7f3bfc goodbye PushRegs 2006-07-17 01:36:39 +00:00
rsc c54c79267f nitpicks 2006-07-17 01:25:22 +00:00
rsc 564f787e91 Eliminate annoying Pseudodesc structure.
Eliminate unnecessary parts of mmu.h.
2006-07-16 16:55:52 +00:00
rsc ef2bd07ae4 standardize on not using foo_ prefix in struct foo 2006-07-16 15:41:47 +00:00
rsc 72fef4f855 Don't kill process when inside kernel. 2006-07-16 02:09:45 +00:00
rsc 6f2b626d28 remove non-idiomatic increment/decrement 2006-07-16 01:52:22 +00:00
rsc 65bd8e139a New scheduler.
Removed cli and sti stack in favor of tracking
number of locks held on each CPU and explicit
conditionals in spinlock.c.
2006-07-16 01:15:28 +00:00
rtm 46bbd72f3e no more recursive locks
wakeup1() assumes you hold proc_table_lock
sleep(chan, lock) provides atomic sleep-and-release to wait for condition
ugly code in swtch/scheduler to implement new sleep
fix lots of bugs in pipes, wait, and exit
fix bugs if timer interrupt goes off in schedule()
console locks per line, not per byte
2006-07-15 12:03:57 +00:00
rtm 6eb6f10c56 passes both usertests
exit had acquire where I meant release
swtch now checks that you hold no locks
2006-07-12 15:35:33 +00:00
rtm 4e8f237be8 no more big kernel lock
succeeds at usertests.c pipe test
2006-07-12 01:48:35 +00:00
rtm b548df152b pre-empt both user and kernel, in clock interrupt
usertest.c tests pre-emption
kill()
2006-07-11 17:39:45 +00:00
rsc 5ce9751cab Changes to allow use of native x86 ELF compilers, which on my
Linux 2.4 box using gcc 3.4.6 don't seem to follow the same
conventions as the i386-jos-elf-gcc compilers.
Can run make 'TOOLPREFIX=' or edit the Makefile.

curproc[cpu()] can now be NULL, indicating that no proc is running.
This seemed safer to me than having curproc[0] and curproc[1]
both pointing at proc[0] potentially.

The old implementation of swtch depended on the stack frame layout
used inside swtch being okay to return from on the other stack
(exactly the V6 you are not expected to understand this).
It also could be called in two contexts: at boot time, to schedule
the very first process, and later, on behalf of a process, to sleep
or schedule some other process.

I split this into two functions: scheduler and swtch.

The scheduler is now a separate never-returning function, invoked
by each cpu once set up.  The scheduler looks like:

	scheduler() {
		setjmp(cpu.context);

		pick proc to schedule
		blah blah blah

		longjmp(proc.context)
	}

The new swtch is intended to be called only when curproc[cpu()] is not NULL,
that is, only on behalf of a user proc.  It does:

	swtch() {
		if(setjmp(proc.context) == 0)
			longjmp(cpu.context)
	}

to save the current proc context and then jump over to the scheduler,
running on the cpu stack.

Similarly the system call stubs are now in assembly in usys.S to avoid
needing to know the details of stack frame layout used by the compiler.

Also various changes in the debugging prints.
2006-07-11 01:07:40 +00:00
kaashoek 7837c71b32 disable all interrupts when acquiring lock
user program that makes a blocking system call
2006-07-06 21:47:22 +00:00
kaashoek b22d898297 timer interrupts
disk interrupts (assuming bochs has a bug)
2006-07-05 20:00:14 +00:00
rtm 8b4e2a08fe swtch saves callee-saved registers
swtch idles on per-CPU stack, not on calling process's stack
fix pipe bugs
usertest.c tests pipes, fork, exit, close
2006-07-01 21:26:01 +00:00
kaashoek bd303ed060 timer interrupts 2006-06-28 16:35:03 +00:00
rtm c41f1de5d4 file descriptors
pipes
2006-06-27 14:35:53 +00:00
rtm b61c2547b8 system call return values
initialize 2nd cpu's idt
2006-06-26 20:31:52 +00:00
rtm df5cc91659 compile "user programs"
curproc array
2006-06-22 20:47:23 +00:00
rtm a4c03dea09 primitive fork and exit system calls 2006-06-15 16:02:20 +00:00
rtm cb83c71628 fix some trap bugs 2006-06-13 22:08:20 +00:00
rtm 84eb544b23 foo 2006-06-13 15:50:40 +00:00