Commit Graph

4 Commits

Author SHA1 Message Date
Giacomo Tesio 99855d60d6 kernel: move chdir to libc using devself/devproc
Added wdir to devself and devproc:

- read '#0/wdir' to get the working directory of the calling process
  NOTE that a read(fd, nil, -1) will return the negated length
  of the working directory, just in case you want to
  allocate the memory required

- read '/proc/n/wdir' to know the working directory of process n
  (read(fd, nil, -1) still returns the negated length)

- write '#0/wdir' to change the working directory of the calling process
  NOTE: no offset is allowed and the provided string must
  be null terminated

- write '/proc/n/wdir' to change the working directory of process n
  NOTE: no offset is allowed and the provided string must
  be null terminated; moreover if another process change the working
  directory change during the write, the current process will
  receive an error.

In libc updated getwd() and chdir().
Also modified pwd to get advantage of the new file.

To test, run /arch/amd64/qa/kern/wdir.rc or simply try

	% pwd
	/usr/glenda
	% echo -n /tmp > /proc/$pid/wdir
        % pwd
        /tmp
        % cat '#0/wdir' && echo
        /tmp

The expected use cases for wdir in devproc are rio and acme.

Also, note that we could theoretically remove the cd builtin
from rc and simply implement it as a rc function.
We don't do that to preserve rc portability to other OS.
2016-12-15 22:42:01 +01:00
Giacomo Tesio c6de6b66e9 kernel: introduce devself
Devself provides to each process access to its own structures.

So far it contains four files:

- pid
- ppid
- pipes	used to implement pipe(2)
- segments used to implement segattach, segdetach and segfree
2016-12-11 01:26:08 +01:00
Giacomo Tesio f52a185030 decouple Jehanne from 9P2000 (as much as needed)
Jehanne is going to use a new file protocol, but Plan 9 is really
coupled with 9P2000.

Renamed fcall.h as 9P2000.h and introduced specific constants such
as NP_OREAD, NP_OWRITE and so on, so that we can use different values
in the kernel and new protocol.

Renamed devmnt to devninep, since it's actually a device serving 9P2000
file systems.

Also, fixed 9P2000 support in Jehanne, that was broken with the introduction
of OSTAT.
2016-12-06 23:01:45 +01:00
Giacomo Tesio 38aca7a581 first usable version of kernel and commands
After an year of hard work, this is a first "usable" version of Jehanne.
2016-11-26 03:49:29 +01:00