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54 commits

Author SHA1 Message Date
Ben Gras
b6ea15115c kernel: facility for user-visible memory
. map all objects named usermapped_*.o with globally visible
	  pages; usermapped_glo_*.o with the VM 'global' bit on, i.e.
	  permanently in tlb (very scarce resource!)
	. added kinfo, machine, kmessages and loadinfo for a start
	. modified log, tty to make use of the shared messages struct
2012-07-28 20:57:38 +00:00
Ben Gras
50e2064049 No more intel/minix segments.
This commit removes all traces of Minix segments (the text/data/stack
memory map abstraction in the kernel) and significance of Intel segments
(hardware segments like CS, DS that add offsets to all addressing before
page table translation). This ultimately simplifies the memory layout
and addressing and makes the same layout possible on non-Intel
architectures.

There are only two types of addresses in the world now: virtual
and physical; even the kernel and processes have the same virtual
address space. Kernel and user processes can be distinguished at a
glance as processes won't use 0xF0000000 and above.

No static pre-allocated memory sizes exist any more.

Changes to booting:
        . The pre_init.c leaves the kernel and modules exactly as
          they were left by the bootloader in physical memory
        . The kernel starts running using physical addressing,
          loaded at a fixed location given in its linker script by the
          bootloader.  All code and data in this phase are linked to
          this fixed low location.
        . It makes a bootstrap pagetable to map itself to a
          fixed high location (also in linker script) and jumps to
          the high address. All code and data then use this high addressing.
        . All code/data symbols linked at the low addresses is prefixed by
          an objcopy step with __k_unpaged_*, so that that code cannot
          reference highly-linked symbols (which aren't valid yet) or vice
          versa (symbols that aren't valid any more).
        . The two addressing modes are separated in the linker script by
          collecting the unpaged_*.o objects and linking them with low
          addresses, and linking the rest high. Some objects are linked
          twice, once low and once high.
        . The bootstrap phase passes a lot of information (e.g. free memory
          list, physical location of the modules, etc.) using the kinfo
          struct.
        . After this bootstrap the low-linked part is freed.
        . The kernel maps in VM into the bootstrap page table so that VM can
          begin executing. Its first job is to make page tables for all other
          boot processes. So VM runs before RS, and RS gets a fully dynamic,
          VM-managed address space. VM gets its privilege info from RS as usual
          but that happens after RS starts running.
        . Both the kernel loading VM and VM organizing boot processes happen
	  using the libexec logic. This removes the last reason for VM to
	  still know much about exec() and vm/exec.c is gone.

Further Implementation:
        . All segments are based at 0 and have a 4 GB limit.
        . The kernel is mapped in at the top of the virtual address
          space so as not to constrain the user processes.
        . Processes do not use segments from the LDT at all; there are
          no segments in the LDT any more, so no LLDT is needed.
        . The Minix segments T/D/S are gone and so none of the
          user-space or in-kernel copy functions use them. The copy
          functions use a process endpoint of NONE to realize it's
          a physical address, virtual otherwise.
        . The umap call only makes sense to translate a virtual address
          to a physical address now.
        . Segments-related calls like newmap and alloc_segments are gone.
        . All segments-related translation in VM is gone (vir2map etc).
        . Initialization in VM is simpler as no moving around is necessary.
        . VM and all other boot processes can be linked wherever they wish
          and will be mapped in at the right location by the kernel and VM
          respectively.

Other changes:
        . The multiboot code is less special: it does not use mb_print
          for its diagnostics any more but uses printf() as normal, saving
          the output into the diagnostics buffer, only printing to the
          screen using the direct print functions if a panic() occurs.
        . The multiboot code uses the flexible 'free memory map list'
          style to receive the list of free memory if available.
        . The kernel determines the memory layout of the processes to
          a degree: it tells VM where the kernel starts and ends and
          where the kernel wants the top of the process to be. VM then
          uses this entire range, i.e. the stack is right at the top,
          and mmap()ped bits of memory are placed below that downwards,
          and the break grows upwards.

Other Consequences:
        . Every process gets its own page table as address spaces
          can't be separated any more by segments.
        . As all segments are 0-based, there is no distinction between
          virtual and linear addresses, nor between userspace and
          kernel addresses.
        . Less work is done when context switching, leading to a net
          performance increase. (8% faster on my machine for 'make servers'.)
	. The layout and configuration of the GDT makes sysenter and syscall
	  possible.
2012-07-15 22:30:15 +02:00
Ben Gras
2bfeeed885 drop segment from safecopy invocations
. all invocations were S or D, so can safely be dropped
	  to prepare for the segmentless world
	. still assign D to the SCP_SEG field in the message
	  to make previous kernels usable
2012-06-16 16:22:51 +00:00
Ben Gras
7336a67dfe retire PUBLIC, PRIVATE and FORWARD 2012-03-25 21:58:14 +02:00
Ben Gras
6a73e85ad1 retire _PROTOTYPE
. only good for obsolete K&R support
	. also remove a stray ansi.h and the proto cmd
2012-03-25 16:17:10 +02:00
David van Moolenbroek
ca95f69f25 drivers: resolve compiler warnings 2012-03-05 22:32:55 +01:00
David van Moolenbroek
b4d909d415 Split block/character protocols and libdriver
This patch separates the character and block driver communication
protocols. The old character protocol remains the same, but a new
block protocol is introduced. The libdriver library is replaced by
two new libraries: libchardriver and libblockdriver. Their exposed
API, and drivers that use them, have been updated accordingly.
Together, libbdev and libblockdriver now completely abstract away
the message format used by the block protocol. As the memory driver
is both a character and a block device driver, it now implements its
own message loop.

The most important semantic change made to the block protocol is that
it is no longer possible to return both partial results and an error
for a single transfer. This simplifies the interaction between the
caller and the driver, as the I/O vector no longer needs to be copied
back. Also, drivers are now no longer supposed to decide based on the
layout of the I/O vector when a transfer should be cut short. Put
simply, transfers are now supposed to either succeed completely, or
result in an error.

After this patch, the state of the various pieces is as follows:
- block protocol: stable
- libbdev API: stable for synchronous communication
- libblockdriver API: needs slight revision (the drvlib/partition API
  in particular; the threading API will also change shortly)
- character protocol: needs cleanup
- libchardriver API: needs cleanup accordingly
- driver restarts: largely unsupported until endpoint changes are
  reintroduced

As a side effect, this patch eliminates several bugs, hacks, and gcc
-Wall and -W warnings all over the place. It probably introduces a
few new ones, too.

Update warning: this patch changes the protocol between MFS and disk
drivers, so in order to use old/new images, the MFS from the ramdisk
must be used to mount all file systems.
2011-11-23 14:06:37 +01:00
Arun Thomas
cb54d96eec Remove legacy boot monitor vars 2011-09-16 20:10:47 +02:00
Ben Gras
3a44cd477b tty: handle REVIVE case on console device
. can happen on e.g. ^S
	. reported by Stephen Hatton
2011-08-09 16:59:01 +00:00
David van Moolenbroek
c51cd5fe91 Server/driver protocols: no longer allow third-party copies.
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed
to know which actual process to copy data from/to, as that process may
not always be the caller. Now that we have full safecopy support, these
fields have become useless for that purpose: the owner of the grant is
*always* the caller. Allowing the caller to supply another endpoint is
in fact dangerous, because the callee may then end up using a grant
from a third party. One could call this a variant of the confused
deputy problem.

From now on, safecopy calls should always use the caller's endpoint as
grant owner. This fully obsoletes the DL_ENDPT field in the
inet/ethernet protocol. IO_ENDPT has other uses besides identifying the
grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only
because that is a more fitting name (it should never be used for I/O
after all), but also in order to intentionally break any old system
source code outside the base system. If this patch breaks your code,
fixing it is fairly simple:

- DL_ENDPT should be replaced with m_source;
- IO_ENDPT should be replaced with m_source when used for safecopies;
- IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g.
  when setting REP_ENDPT, matching requests in CANCEL calls, getting
  DEV_SELECT flags, and retrieving of the real user process's endpoint
  in DEV_OPEN.

The changes in this patch are binary backward compatible.
2011-04-11 17:35:05 +00:00
David van Moolenbroek
f56c4001d5 TTY/LOG driver cleanup:
- remove non-safecopy support from TTY
- make TTY warning-free with gcc -Wall
- remove obsolete diagnostics support
2011-03-25 10:43:24 +00:00
David van Moolenbroek
895850b8cf move timers code to libsys 2010-07-09 12:58:18 +00:00
Ben Gras
09958abda8 tty: don't use custom kputc; this fixes tty printf()s. 2010-05-04 09:26:01 +00:00
Kees van Reeuwijk
b412fb7ad5 Code cleanup: remove unused #include, variables and code, 2010-04-15 18:49:36 +00:00
Kees van Reeuwijk
94a81c840a Removed unused variables, added const where possible. 2010-04-07 11:25:51 +00:00
Arun Thomas
436d6012a3 Convert drivers/ and servers/ over to bsdmake
-Move libdriver to lib/
-Install all boot image services on filesystem to aid restartability
2010-03-22 21:25:22 +00:00
Cristiano Giuffrida
cb176df60f New RS and new signal handling for system processes.
UPDATING INFO:
20100317:
        /usr/src/etc/system.conf updated to ignore default kernel calls: copy
        it (or merge it) to /etc/system.conf.
        The hello driver (/dev/hello) added to the distribution:
        # cd /usr/src/commands/scripts && make clean install
        # cd /dev && MAKEDEV hello

KERNEL CHANGES:
- Generic signal handling support. The kernel no longer assumes PM as a signal
manager for every process. The signal manager of a given process can now be
specified in its privilege slot. When a signal has to be delivered, the kernel
performs the lookup and forwards the signal to the appropriate signal manager.
PM is the default signal manager for user processes, RS is the default signal
manager for system processes. To enable ptrace()ing for system processes, it
is sufficient to change the default signal manager to PM. This will temporarily
disable crash recovery, though.
- sys_exit() is now split into sys_exit() (i.e. exit() for system processes,
which generates a self-termination signal), and sys_clear() (i.e. used by PM
to ask the kernel to clear a process slot when a process exits).
- Added a new kernel call (i.e. sys_update()) to swap two process slots and
implement live update.

PM CHANGES:
- Posix signal handling is no longer allowed for system processes. System
signals are split into two fixed categories: termination and non-termination
signals. When a non-termination signaled is processed, PM transforms the signal
into an IPC message and delivers the message to the system process. When a
termination signal is processed, PM terminates the process.
- PM no longer assumes itself as the signal manager for system processes. It now
makes sure that every system signal goes through the kernel before being
actually processes. The kernel will then dispatch the signal to the appropriate
signal manager which may or may not be PM.

SYSLIB CHANGES:
- Simplified SEF init and LU callbacks.
- Added additional predefined SEF callbacks to debug crash recovery and
live update.
- Fixed a temporary ack in the SEF init protocol. SEF init reply is now
completely synchronous.
- Added SEF signal event type to provide a uniform interface for system
processes to deal with signals. A sef_cb_signal_handler() callback is
available for system processes to handle every received signal. A
sef_cb_signal_manager() callback is used by signal managers to process
system signals on behalf of the kernel.
- Fixed a few bugs with memory mapping and DS.

VM CHANGES:
- Page faults and memory requests coming from the kernel are now implemented
using signals.
- Added a new VM call to swap two process slots and implement live update.
- The call is used by RS at update time and in turn invokes the kernel call
sys_update().

RS CHANGES:
- RS has been reworked with a better functional decomposition.
- Better kernel call masks. com.h now defines the set of very basic kernel calls
every system service is allowed to use. This makes system.conf simpler and
easier to maintain. In addition, this guarantees a higher level of isolation
for system libraries that use one or more kernel calls internally (e.g. printf).
- RS is the default signal manager for system processes. By default, RS
intercepts every signal delivered to every system process. This makes crash
recovery possible before bringing PM and friends in the loop.
- RS now supports fast rollback when something goes wrong while initializing
the new version during a live update.
- Live update is now implemented by keeping the two versions side-by-side and
swapping the process slots when the old version is ready to update.
- Crash recovery is now implemented by keeping the two versions side-by-side
and cleaning up the old version only when the recovery process is complete.

DS CHANGES:
- Fixed a bug when the process doing ds_publish() or ds_delete() is not known
by DS.
- Fixed the completely broken support for strings. String publishing is now
implemented in the system library and simply wraps publishing of memory ranges.
Ideally, we should adopt a similar approach for other data types as well.
- Test suite fixed.

DRIVER CHANGES:
- The hello driver has been added to the Minix distribution to demonstrate basic
live update and crash recovery functionalities.
- Other drivers have been adapted to conform the new SEF interface.
2010-03-17 01:15:29 +00:00
Ben Gras
35a108b911 panic() cleanup.
this change
   - makes panic() variadic, doing full printf() formatting -
     no more NO_NUM, and no more separate printf() statements
     needed to print extra info (or something in hex) before panicing
   - unifies panic() - same panic() name and usage for everyone -
     vm, kernel and rest have different names/syntax currently
     in order to implement their own luxuries, but no longer
   - throws out the 1st argument, to make source less noisy.
     the panic() in syslib retrieves the server name from the kernel
     so it should be clear enough who is panicing; e.g.
         panic("sigaction failed: %d", errno);
     looks like:
         at_wini(73130): panic: sigaction failed: 0
         syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a
   - throws out report() - printf() is more convenient and powerful
   - harmonizes/fixes the use of panic() - there were a few places
     that used printf-style formatting (didn't work) and newlines
     (messes up the formatting) in panic()
   - throws out a few per-server panic() functions
   - cleans up a tie-in of tty with panic()

merging printf() and panic() statements to be done incrementally.
2010-03-05 15:05:11 +00:00
Kees van Reeuwijk
064cb7583a Lots of small code cleanup: make symbols local, remove unused symbols,
fixed a typo, removed a now unused header file.
Use #include <..> for header files that represent libraries.
2010-02-09 15:23:38 +00:00
David van Moolenbroek
492d663444 TTY fixes:
- reenable code to restore screen/cursor at shutdown
- add proper signal checking logic
- lock to first console during shutdown
2009-12-21 23:19:01 +00:00
Ben Gras
89bf7bae27 - tty: only report unrecognized scancodes once; forget about
remembering the origin and cursor position as that feature didn't
   really work properly anyway
 - tty: map in video and font memory using a vm call, access it from C,
   thereby eliminating pesky weird segment calls and assembly to access it,
   and unbreaks loadfont (Roman Ignatov)
 - bios_wini: fix bios_wini by allocating a <1MB buffers for it
 - memory: preallocate ramdisk, makes it a bit faster (and doesn't
   fail halfway if you allocate a huge one)
 - floppy: use <1MB buffer
 - ramdisk proto: because of the 2x1 page reservations, binaries
   got a little fatter and didn't fit on the ramdisk any more.
   increase it.
2009-09-21 14:25:54 +00:00
Ben Gras
dd56aa321f to let tty run with its own page table (instead of with the kernel identity
map table), make it map in video memory.

sadly, this breaks tty in non-paged mode.

happily, this simplifies the code by throwing out the messing
around with segments, and throws out vidcopy.s.
2009-05-12 12:43:18 +00:00
Ben Gras
3cc092ff06 . new kernel call sysctl for generic unprivileged system operations;
now used for printing diagnostic messages through the kernel message
   buffer. this lets processes print diagnostics without sending messages
   to tty and log directly, simplifying the message protocol a lot and
   reducing difficulties with deadlocks and other situations in which
   diagnostics are blackholed (e.g. grants don't work). this makes
   DIAGNOSTICS(_S), ASYN_DIAGNOSTICS and DIAG_REPL obsolete, although tty
   and log still accept the codes for 'old' binaries. This also simplifies
   diagnostics in several servers and drivers - only tty needs its own
   kputc() now.
 . simplifications in vfs, and some effort to get the vnode references
   right (consistent) even during shutdown. m_mounted_on is now NULL
   for root filesystems (!) (the original and new root), a less awkward
   special case than 'm_mounted_on == m_root_node'. root now has exactly
   one reference, to root, if no files are open, just like all other
   filesystems. m_driver_e is unused.
2009-01-26 17:43:59 +00:00
Ben Gras
36909196cf make bootinfo valid immediately 2009-01-14 08:56:20 +00:00
Ben Gras
f4d0d635fd - hz dynamic
- new map /dev/video implementation
 - ser_putc into library
2008-12-08 16:40:29 +00:00
Ben Gras
c078ec0331 Basic VM and other minor improvements.
Not complete, probably not fully debugged or optimized.
2008-11-19 12:26:10 +00:00
Philip Homburg
00ef93d6a2 Use nonblocking sends to reply, fixed reply message for DIAGNOSTICS(_S) 2008-02-22 16:03:00 +00:00
Philip Homburg
1d4afb3599 Compile-time option to duplicate console output to the first serial line 2007-08-07 11:27:03 +00:00
Philip Homburg
bb659b1ad6 Disabled ser_putc for reporting debug internal to tty over the serial line.
Disabled return statement for serial debug input in the kernel.
2007-04-23 14:59:32 +00:00
Ben Gras
8ea438ae93 Retired DEV_{READ,WRITE,GATHER,SCATTER,IOCTL} (safe versions *_S are to
be used and drivers should never receieve these 'unsafe' variants
any more).
2007-02-07 16:22:19 +00:00
Ben Gras
cbfcdcc4c2 Use grant address type in loadfont ioctl. 2006-07-21 14:39:48 +00:00
Philip Homburg
f6d1f6fdf6 Switch to vc 0 and softscrolling when /dev/video is opened and switch back
at the close. This should prevent problems with X on (emulated) Cirrus
cards.
2006-07-19 11:50:18 +00:00
Philip Homburg
ee09d50403 Changed to use sys_readbios to get screen parameters. Added safecopy version
to get log messages.
2006-07-10 12:37:39 +00:00
Ben Gras
1c8b206a5d . Safe I/O, ioctl() and DIAGNOSTICS variants conversion - safe copies,
include grant id in DEV_REVIVE messages.
. Removal of TTY_FLAGS field (and so O_NONBLOCK support).
. Fixed CANCEL behaviour and return code on blocking I/O,
  previously handled by O_NONBLOCK
. Totally removed REVIVE replies, previously still possible on
  blocking ioctls (REVIVE directly called) and ptys (missing TTY_REVIVE
  check), removes deadlock bug with FS
. Removed obsolete *COMPAT options and associated code
2006-06-20 09:02:54 +00:00
Philip Homburg
e9aabcf2f8 Disabled building rescue driver (no longer needed). Moved allocmem from
library to the memory driver. Always put output from within TTY directly on
the console. Removed second include of driver.h from tty.c. Made tty_inrepcode
bigger. First step to move PM and FS calls that are not regular (API)
system calls out of callnr.h (renumbered them, and removed them from the
table.c files). Imported the Minix-vmd uname implementation. This provides
a more stable ABI than the current implementation. Added a bit of security
checking. Unfortunately not nearly enough to get a secure system. Fixed a
bug related to the sizes of the programs in the image (in PM patch_mem_chunks).
2006-05-19 12:19:37 +00:00
Ben Gras
9f6b2666e1 Compiler warnings fix 2006-03-24 14:16:13 +00:00
Ben Gras
f877da3aec endpoint migration for drivers.
mostly renaming message field names to the new names.

tty stored process numbers in chars in tty and pty structs - now ints.
2006-03-03 10:21:45 +00:00
Philip Homburg
5556281540 Added /dev/video for mapping video memory. 2005-11-09 15:45:48 +00:00
Philip Homburg
0b5a135a67 Raw keyboard and AUX support. Needs cleaning up. 2005-10-24 13:57:19 +00:00
Philip Homburg
9f8f2484dd Forward debug output that originates within TTY first to the log device. 2005-09-30 13:01:34 +00:00
Ben Gras
e3709af1b8 Andy's code fixes 2005-09-11 17:09:11 +00:00
Ben Gras
e2e90b1fdc Remove double-blank lines (Al) 2005-08-22 15:17:42 +00:00
Jorrit Herder
74711a3b14 Check if kernel calls is allowed (from process' call mask) added. Not yet
enforced. If a call is denied, this will be kprinted. Please report any such
errors, so that I can adjust the mask before returning errors instead of
warnings.

Wrote CMOS driver. All CMOS code from FS has been removed. Currently the
driver only supports get time calls. Set time is left out as an exercise
for the book readers ... startup scripts were updated because the CMOS driver
is needed early on. (IS got same treatment.) Don't forget to run MAKEDEV cmos
in /dev/, otherwise the driver cannot be loaded.
2005-08-04 19:23:03 +00:00
Jorrit Herder
aec394a330 Updated drivers according to syslib interface changes. 2005-07-29 15:00:22 +00:00
Jorrit Herder
fe0dcb5c00 AT driver is not modified (debugging only);
TTY: select and revive with new notify and FS call back;
kernel: removed old notify code; removed ugly prepare_shutdown timer
kputc: don't send to FS if PRINTF_PROC fails
2005-07-27 14:32:16 +00:00
Jorrit Herder
279250889f Renamed some system library functionality. 2005-07-14 15:15:18 +00:00
Ben Gras
471e0448c3 Changed timer library function args.
Added select() support for tty fd's (not ptys yet).
2005-06-17 13:37:41 +00:00
Jorrit Herder
6d23f072f3 Cleaned up src/lib/utils library. Renamed server_ functions to more logical
names. All system processes can now either use panic() or report() from
libutils, or redefine their own function. Assertions are done via the standard
<assert.h> functionality.
2005-06-01 14:31:00 +00:00
Jorrit Herder
0165662cd9 Replaced flagalrm() timers with another technique to check for timeouts.
This allowed removing the p_flagarlm timer from the kernel's process table.
Furthermore, I merged p_syncalrm and p_signalrm into p_alarm_timer to save
even more space. Note that processes can no longer have both a signal and
synchronous alarm timer outstanding as of now.
2005-05-31 14:43:04 +00:00
Ben Gras
cd72f80639 Disabled clearing screen in tty driver, started console printing after an
initial 1-line scroll at last line. If clearing screen in trailer of boot
monitor is disabled, all previous boot monitor and console messages are
preserved on rebooting.

All that's needed now is a scrollback buffer to see all old messages..
(Even from the boot monitor, bios, previous boots...)
2005-05-30 15:09:51 +00:00