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119 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 0073beee52 remove dead code 2007-08-21 19:22:27 +00:00
rsc f32f3638f4 Various cleanup:
- Got rid of dummy proc[0].  Now proc[0] is init.
 - Added initcode.S to exec /init, so that /init is
   just a regular binary.
 - Moved exec out of sysfile to exec.c
 - Moved code dealing with fs guts (like struct inode)
   from sysfile.c to fs.c.  Code dealing with system call
   arguments stays in sysfile.c
 - Refactored directory routines in fs.c; should be simpler.
 - Changed iget to return *unlocked* inode structure.
   This solves the lookup-then-use race in namei
   without introducing deadlocks.
   It also enabled getting rid of the dummy proc[0].
2007-08-21 19:22:08 +00:00
rsc bcca6c6bde shuffle fs.c in bottom-up order 2007-08-20 18:23:52 +00:00
rsc 8c4b5fc5b3 Gcc expects to be able to pick up the return
address off the stack, so put one there for it.
(Bug was hidden by bad segment limits.)
2007-08-14 04:56:30 +00:00
rsc dca5b5ca2e avoid assignments in declarations 2007-08-10 17:17:42 +00:00
rsc c664dd5d23 missing void 2007-08-08 09:32:39 +00:00
rsc 5d0fe3445b more bugs 2007-08-08 09:10:16 +00:00
rsc b6dc6187f7 add DPL_USER constant 2007-08-08 09:02:42 +00:00
rsc f83f7ce2f6 set init name 2007-08-08 08:57:55 +00:00
rsc 4fb684548a formatting nits 2006-09-08 15:14:43 +00:00
rsc efb01c1dc0 only need a page 2006-09-08 15:09:48 +00:00
kaashoek 5cb7877e0f use bootstrap processor as specified by MP table. typically 0, but not
guaranteed.
2006-09-08 14:48:07 +00:00
kaashoek 8e1d1ec934 some comment changes 2006-09-08 14:36:44 +00:00
rsc 7e019461c8 fix build 2006-09-07 14:10:52 +00:00
kaashoek e00baa9f5d get precedence of <, >, and | right
simplify
2006-09-07 02:15:28 +00:00
kaashoek f70172129c run without lapic and ioapic, if they are not present
if no lapic available, use 8253pit for clock
now xv6 runs both on qemu (uniprocessor) and bochs (uniprocessor and MP)
2006-09-07 01:37:58 +00:00
rsc 50e514be98 fd_* => file_* 2006-09-06 18:43:45 +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
rtm dfcc5b997c prune unneeded panics and debug output 2006-08-29 19:06:37 +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
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
kaashoek 69332d1918 oops 2006-08-15 15:54:53 +00:00
kaashoek e958c538fa commented out code for cwd 2006-08-15 15:53:46 +00:00
rtm 9e5970d596 link() 2006-08-13 02:12:44 +00:00
rtm 17a856577f init creates console, opens 0/1/2, runs sh
sh accepts 0-argument commands (like userfs)
reads from console
2006-08-11 13:55:18 +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
kaashoek 6fa5ffb56f devsw
checkpoint: write(fd,"hello\n",6) where fd is a console dev almost works
2006-08-09 16:04:04 +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
kaashoek c8b29f6d03 better interrupt plan---this one appears to work
ioapic
2006-08-04 18:12:31 +00:00
rtm 32630628a9 open() 2006-07-29 09:35:02 +00:00
rtm c59361f143 primitive exec 2006-07-27 21:10:00 +00:00
rtm 2927081628 uint32_t -> uint &c 2006-07-20 09:07:53 +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 6e6a1dd7d7 various little fixes that should have been in earlier checkins 2006-07-16 16:06:03 +00:00
rsc 8a7eb80e47 fix main return type 2006-07-16 16:03:51 +00:00
rsc b74f4b57ae Keep interrupts disabled during startup. 2006-07-16 15:50:13 +00:00
rsc ef2bd07ae4 standardize on not using foo_ prefix in struct foo 2006-07-16 15:41:47 +00:00
rsc 856e1fc1ad Attempt to clean up newproc somewhat.
Also remove all calls to memcpy in favor of
memmove, which has defined semantics when
the ranges overlap.  The fact that memcpy was
working in console.c to scroll the screen is not
guaranteed by all implementations.
2006-07-16 01:47:40 +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
rsc 3497670122 silence load_icode signedness warning 2006-07-15 17:23:17 +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
kaashoek f27a68a24a extract lapic code from mp.c 2006-07-12 17:00:54 +00:00
rtm 8148b6ee53 i think my cmpxchg use was wrong in acquire
nesting cli/sti: release shouldn't always enable interrupts
separate setup of lapic from starting of other cpus, so cpu() works earlier
flag to disable locking in console output
make locks work even when curproc==0
(still crashes in clock interrupt)
2006-07-12 11:15:38 +00:00
rtm 4e8f237be8 no more big kernel lock
succeeds at usertests.c pipe test
2006-07-12 01:48:35 +00:00
rtm b41b38d0da give each cpu its own clock, so that preemption works on cpu 1 2006-07-11 18:45:27 +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 72ea69fbdf read the disk using interrupts 2006-07-10 13:08:37 +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
kaashoek 8352b99801 oops 2006-06-22 15:28:09 +00:00
kaashoek 21a88fd487 checkpoint. booting second processor. stack is messed up, but thanks to cliff
and plan 9 code, at least boots and gets into C code.
2006-06-22 01:28:57 +00:00
kaashoek 7baa34a421 start on MP; detect MP configuration 2006-06-21 01:53:07 +00:00
rtm ae6e8aa730 checkpoint 2006-06-16 20:29:25 +00:00
rtm be0a7eacda sleep, wakeup, wait, exit 2006-06-15 19:58:01 +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 0a70d042d0 more or less take traps/interrupts 2006-06-13 15:50:06 +00:00
rtm 55e95b16db import 2006-06-12 15:22:12 +00:00