From 5f46b272fe315cf477e45ec8523aba21d10b52e6 Mon Sep 17 00:00:00 2001 From: Frans Kaashoek Date: Mon, 5 Sep 2011 20:54:25 -0400 Subject: [PATCH] Shorten history of xv6 Cut section about commentary Add (failing) link to xv6 source section pointing to the text. Delete the incorrect/incomplete list of universities using jos/xv6 --- web/index.html | 135 ++++++++----------------------------------------- 1 file changed, 20 insertions(+), 115 deletions(-) diff --git a/web/index.html b/web/index.html index d7bba91..c14e2d0 100644 --- a/web/index.html +++ b/web/index.html @@ -43,22 +43,15 @@ systems Engineering. We hope that xv6 will be useful in other courses too. This page collects resources to aid the use of xv6 in other courses, including a commentary on the source code itself. -

Status: The xv6 code is in pretty good shape, but -the commentary is rough. -

History and Background

-

For many years, MIT had no operating systems course. In the fall -of 2002, Frans Kaashoek, Josh Cates, and Emil Sit created a new, -experimental course (6.097) to teach operating systems engineering. -In the course lectures, the class worked through Sixth -Edition Unix (aka V6) using John Lions's famous commentary. In -the lab assignments, students wrote most of an exokernel operating -system, eventually named Jos, for the Intel x86. Exposing students to -multiple systems–V6 and Jos–helped develop a sense of the -spectrum of operating system designs. In the fall of 2003, the -experimental 6.097 became the official course 6.828; the course has -been offered each fall since then. +

For many years, MIT had no operating systems course. In the fall of 2002, +one was created to teach operating systems engineering. In the course lectures, +the class worked through Sixth Edition Unix (aka V6) using +John Lions's famous commentary. In the lab assignments, students wrote most of +an exokernel operating system, eventually named Jos, for the Intel x86. +Exposing students to multiple systems–V6 and Jos–helped develop a +sense of the spectrum of operating system designs.

V6 presented pedagogic challenges from the start. @@ -80,27 +73,18 @@ uniprocessors such as enabling/disabling interrupts) and helps relevance. Finally, writing a new system allowed us to write cleaner versions of the rougher parts of V6, like the scheduler and file system. -

6.828 substituted xv6 for V6 in the fall of 2006. Based on -that experience, we cleaned up rough patches of xv6. Since then, xv6 -has stabilized, so we are making it available in the hopes that others -will find it useful too. - -

-6.828 uses both xv6 and Jos. -Courses taught at UCLA, NYU, Peking University, Stanford, Tsinghua, -and University Texas (Austin) have used -Jos without xv6; we believe other courses could use -xv6 without Jos, though we are not aware of any that have. +6.828 substituted xv6 for V6 in the fall of 2006.

Xv6 sources

-The latest xv6 is xv6-rev5.tar.gz. -We distribute the sources in electronic form but also as -a printed booklet with line numbers that keep everyone -together during lectures. The booklet is available as -xv6-rev5.pdf. -The xv6 source code is licensed under the traditional MIT license; -see the LICENSE file in the source distribution. +The latest xv6 is xv6-rev5.tar.gz. We distribute +the sources in electronic form but also as a printed booklet with line numbers +that keep everyone together during lectures. The booklet is available as xv6-rev5.pdf. The xv6 source code is licensed under +the traditional MIT +license; see the LICENSE file in the source distribution. To help students +read through xv6 and learn about the main ideas in operating systems we also +distribute a textbook/commentary for the latest xv6.

xv6 compiles using the GNU C compiler, @@ -115,89 +99,10 @@ can be found on the 6.828 tools page.

Xv6 lecture material

-In 6.828, the lectures in the first half of the course introduce the -PC hardware, the Intel x86, and then xv6. The lectures in the second -half consider advanced topics using research papers; for some, xv6 -serves as a useful base for making discussions concrete. The lecture -notes are available from the 6.828 schedule page, and the chapters of -the commentary are below. - -

Xv6 commentary (rough)

- -

The chapters are rough drafts. - -

Introduction yet to be written.
-

- -Chapter 0: Operating system interfaces -
-The Unix system call interface. (rev 4) -
- -Chapter 1: Bootstrap -
-From power on to kernel start. (rev 4) -
- -Chapter 2: Processes -
-Memory and process allocation, segments, the first user process. (rev 4) -
- -Chapter 3: Traps -
-Low-level trap mechanism, trap handler, system call arguments, sbrk, fork. -
- -Chapter 4: Locks -
-Locks and interrupts. -
- -Chapter 5: Scheduling and coordination -
-Scheduling, sleep and wakeup, pipes, wait and exit. -
- -Chapter 6: Buffer cache -
-Buffer cache and IDE disk driver. -
- -Chapter 7: File system data -
-Block in use bitmap, block allocation, inode structure, inode contents, -directories, path names. -
- -Chapter 8: File system calls -
-FIle descriptors, open, close, dup, read, write. -
- -Chapter 9: Exec -
-Exec -
- -Appendix A: Low-level C and inline assembly -
-Intro to C and inline assembly for people who only know Java (say). -Examples drawn entirely from xv6 source. -
- -Appendix B: Additional drivers. -
-Keyboard, screen, probably MP hardware. -
+In 6.828, the lectures in the first half of the course cover the xv6 sources and +text. The lectures in the second half consider advanced topics using research +papers; for some, xv6 serves as a useful base for making discussions concrete. +The lecture notes are available from the 6.828 schedule page.

Unix Version 6