anyway. This patch is useful everywhere with `pintos', but may not be
wanted elsewhere.
+The remaining patches add the `jitter' feature described in the
+project documentation, in which timer interrupts are delivered at
+random intervals.
+
+To apply all the patches, cd into the Bochs directory, then type
+ patch -p1 < $PINTOSROOT/src/misc/bochs-2.1.1.patch
+You will have to supply the proper path to the patch, of course. You
+can provide the --dry-run option to patch if you want to test whether
+the patch would apply cleanly before actually patching.
+
+To apply a subset of the patches, use a text editor to delete the
+unwanted patches, then follow the above instructions.
+
Here's a ./configure invocation for Bochs that works optimally with
the `pintos' utility:
./configure --with-x --with-x11 --with-term --with-nogui
If you want the gdb stub, add --enable-gdb-stub
If you want the internal debugger, add --enable-debugger
+Here are the commands used to build and install all the versions of
+Bochs we make available on the elaines:
+
+cd /tmp && tar xzf ~/bochs-2.1.1.tar.gz && cd bochs-2.1.1
+patch -p1 < $PINTOSROOT/src/misc/bochs-2.1.1.patch
+CFGOPTS="--with-x --with-x11 --with-term --with-nogui --prefix=/usr/class/cs140/i386"
+(mkdir plain &&
+ cd plain &&
+ ../configure $CFGOPTS &&
+ make &&
+ make install)
+(mkdir with-gdb &&
+ cd with-gdb &&
+ ../configure --enable-gdb-stub $CFGOPTS &&
+ make &&
+ cp bochs /usr/class/cs140/i386/bin/bochs-gdb)
+(mkdir with-dbg &&
+ cd with-dbg &&
+ ../configure --enable-debugger $CFGOPTS &&
+ make &&
+ cp bochs /usr/class/cs140/i386/bin/bochs-dbg)
+
diff -urp orig/bochs-2.1.1/Makefile.in bochs-2.1.1/Makefile.in
--- orig/bochs-2.1.1/Makefile.in 2004-02-11 14:28:02.000000000 -0800
+++ bochs-2.1.1/Makefile.in 2004-09-13 15:05:26.281550000 -0700
mem2hex((char *)registers, obuf, NUMREGSBYTES);
put_reply(obuf);
break;
+
+diff -u tmp/bochs-2.1.1/iodev/serial.cc bochs-2.1.1/iodev/serial.cc
--- tmp/bochs-2.1.1/iodev/serial.cc 2004-02-11 14:28:54.000001000 -0800
+++ bochs-2.1.1/iodev/serial.cc 2004-09-14 23:02:04.000001000 -0700
@@ -53,7 +53,7 @@
}
#endif /* def SERIAL_ENABLE */
// nothing for now
+
+diff -urp bochs-2.1.1.orig/bochs.h bochs-2.1.1/bochs.h
+--- bochs-2.1.1.orig/bochs.h 2004-02-11 14:28:03.000000000 -0800
++++ bochs-2.1.1/bochs.h 2004-09-20 17:02:01.000000000 -0700
+@@ -757,4 +757,6 @@ int bx_init_hardware ();
+
+ #endif
+
++extern int jitter;
++
+ #endif /* BX_BOCHS_H */
+diff -urp bochs-2.1.1.orig/iodev/pit82c54.cc bochs-2.1.1/iodev/pit82c54.cc
+--- bochs-2.1.1.orig/iodev/pit82c54.cc 2004-02-11 14:28:53.000000000 -0800
++++ bochs-2.1.1/iodev/pit82c54.cc 2004-09-20 17:18:24.000000000 -0700
+@@ -28,6 +28,7 @@
+
+ #include "bochs.h"
+ #include "pit82c54.h"
++#include <stdlib.h>
+ #define LOG_THIS this->
+
+
+@@ -356,7 +357,13 @@ pit_82C54::clock(Bit8u cnum) {
+ case 2:
+ if(thisctr.count_written) {
+ if(thisctr.triggerGATE || thisctr.first_pass) {
+- set_count(thisctr, thisctr.inlatch);
++ unsigned n = thisctr.inlatch;
++ if (jitter) {
++ n *= (double) rand() / RAND_MAX;
++ if (n < 5)
++ n = 5;
++ }
++ set_count(thisctr, n);
+ thisctr.next_change_time=(thisctr.count_binary-1) & 0xFFFF;
+ thisctr.null_count=0;
+ if(thisctr.inlatch==1) {
+diff -urp bochs-2.1.1.orig/iodev/pit_wrap.cc bochs-2.1.1/iodev/pit_wrap.cc
+diff -urp bochs-2.1.1.orig/iodev/serial.cc bochs-2.1.1/iodev/serial.cc
+diff -urp bochs-2.1.1.orig/main.cc bochs-2.1.1/main.cc
+--- bochs-2.1.1.orig/main.cc 2004-02-11 14:28:41.000000000 -0800
++++ bochs-2.1.1/main.cc 2004-09-20 17:15:39.000000000 -0700
+@@ -58,6 +58,7 @@
+
+
+ int bochsrc_include_count = 0;
++int jitter = 0;
+
+ extern "C" {
+ #include <signal.h>
+@@ -2022,6 +2024,13 @@ bx_init_main (int argc, char *argv[])
+ else if (!strcmp ("-q", argv[arg])) {
+ SIM->get_param_enum(BXP_BOCHS_START)->set (BX_QUICK_START);
+ }
++ else if (!strcmp ("-j", argv[arg])) {
++ if (++arg >= argc) BX_PANIC(("-j must be followed by a number"));
++ else {
++ jitter = 1;
++ srand (atoi (argv[arg]));
++ }
++ }
+ else if (!strcmp ("-f", argv[arg])) {
+ if (++arg >= argc) BX_PANIC(("-f must be followed by a filename"));
+ else bochsrc_filename = argv[arg];