Elaborate on how to get the user program's stack pointer.

[pintos-anon] / doc / userprog.texi

diff --git a/doc/userprog.texi b/doc/userprog.texi
index d401fda025f1f98b81ed78a31c743ccbd30bf68e..75123849b0622bcd7aa312a462cba104a36761de 100644 (file)
--- a/doc/userprog.texi
+++ b/doc/userprog.texi
@@ -19,6 +19,12 @@ start with a fresh copy.  No code from project 1 is required for this
 assignment.  The ``alarm clock'' functionality may be useful in
 projects 3 and 4, but it is not strictly required.
 
 assignment.  The ``alarm clock'' functionality may be useful in
 projects 3 and 4, but it is not strictly required.
 

+You might find it useful to go back and reread how to run the tests
+(@pxref{Testing}).  In particular, the tests for project 2 and later
+projects will probably run faster if you use the qemu emulator, e.g.@:
+via @code{make check PINTOSOPTS='--qemu'}.  The qemu emulator is
+available only on the Linux machines.
+

 @menu
 * Project 2 Background::        
 * Project 2 Suggested Order of Implementation::  
 @menu
 * Project 2 Background::        
 * Project 2 Suggested Order of Implementation::  


@@ -222,9 +228,10 @@ pintos -p ../../examples/echo -a echo -- -f -q run 'echo x'
 
 If you don't want to keep the file system disk around for later use or
 inspection, you can even combine all four steps into a single command.
 
 If you don't want to keep the file system disk around for later use or
 inspection, you can even combine all four steps into a single command.

-The @code{--fs-disk=2} option creates a temporary disk just for the
-duration of the @command{pintos} run.  The Pintos automatic test suite
-makes extensive use of this syntax:
+The @code{--fs-disk=@var{n}} option creates a temporary disk
+approximately @var{n} megabytes in size just for the duration of the
+@command{pintos} run.  The Pintos automatic test suite makes extensive
+use of this syntax:

 
 @example
 pintos --fs-disk=2 -p ../../examples/echo -a echo -- -f -q run 'echo x'
 
 @example
 pintos --fs-disk=2 -p ../../examples/echo -a echo -- -f -q run 'echo x'


@@ -251,7 +258,8 @@ programs.  The @file{Makefile} in this directory
 compiles the provided examples, and you can edit it
 compile your own programs as well.
 
 compiles the provided examples, and you can edit it
 compile your own programs as well.
 

-Pintos loads @dfn{ELF} executables.  ELF is a file format used by Linux,
+Pintos can load @dfn{ELF} executables with the loader provided for you
+in @file{userprog/process.c}.  ELF is a file format used by Linux,

 Solaris, and many other operating systems for object files,
 shared libraries, and executables.  You can actually use any compiler
 and linker that output 80@var{x}86 ELF executables to produce programs
 Solaris, and many other operating systems for object files,
 shared libraries, and executables.  You can actually use any compiler
 and linker that output 80@var{x}86 ELF executables to produce programs


@@ -683,7 +691,8 @@ actual number written, or -1 if no bytes could be written at all.
 
 Fd 1 writes to the console.  Your code to write to the console should
 write all of @var{buffer} in one call to @func{putbuf}, at least as
 
 Fd 1 writes to the console.  Your code to write to the console should
 write all of @var{buffer} in one call to @func{putbuf}, at least as

-long as @var{size} is not bigger than a few hundred bytes.  Otherwise,
+long as @var{size} is not bigger than a few hundred bytes.  (It is
+reasonable to break up larger buffers.)  Otherwise,

 lines of text output by different processes may end up interleaved on
 the console, confusing both human readers and our grading scripts.
 
 lines of text output by different processes may end up interleaved on
 the console, confusing both human readers and our grading scripts.
 


@@ -777,7 +786,8 @@ hurt even now.
 You can use @func{file_deny_write} to prevent writes to an open file.
 Calling @func{file_allow_write} on the file will re-enable them (unless
 the file is denied writes by another opener).  Closing a file will also
 You can use @func{file_deny_write} to prevent writes to an open file.
 Calling @func{file_allow_write} on the file will re-enable them (unless
 the file is denied writes by another opener).  Closing a file will also

-re-enable writes.
+re-enable writes.  Thus, to deny writes to process's executable, you
+must keep it open as long as the process is still running.

 
 @node Project 2 FAQ
 @section FAQ
 
 @node Project 2 FAQ
 @section FAQ


@@ -789,6 +799,12 @@ Here's a summary of our reference solution, produced by the
 @command{diffstat} program.  The final row gives total lines inserted
 and deleted; a changed line counts as both an insertion and a deletion.
 
 @command{diffstat} program.  The final row gives total lines inserted
 and deleted; a changed line counts as both an insertion and a deletion.
 

+The reference solution represents just one possible solution.  Many
+other solutions are also possible and many of those differ greatly from
+the reference solution.  Some excellent solutions may not modify all the
+files modified by the reference solution, and some may modify files not
+modified by the reference solution.
+

 @verbatim
  threads/thread.c     |   13 
  threads/thread.h     |   26 +
 @verbatim
  threads/thread.c     |   13 
  threads/thread.h     |   26 +