From d810034292894081f885458e730dd66fa6349ab2 Mon Sep 17 00:00:00 2001
From: Ben Pfaff <blp@cs.stanford.edu>
Date: Tue, 21 Sep 2004 00:25:03 +0000
Subject: [PATCH] Add jitter feature to Bochs.
---
src/misc/bochs-2.1.1.patch | 68 ++++++++++++++++++++++++++++++++++++++
1 file changed, 68 insertions(+)
diff --git a/src/misc/bochs-2.1.1.patch b/src/misc/bochs-2.1.1.patch
index 942b82f..a88df1c 100644
--- a/src/misc/bochs-2.1.1.patch
+++ b/src/misc/bochs-2.1.1.patch
@@ -14,6 +14,10 @@ connect a serial port to stdout and it doesn't work under Solaris
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 < ~/pintos/src/misc/bochs-2.1.1.patch
You will have to supply the proper path to the patch, of course. You
@@ -162,3 +166,67 @@ diff -urp orig/bochs-2.1.1/gdbstub.cc bochs-2.1.1/gdbstub.cc
}
#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 < 1)
++ n = 1;
++ }
++ 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];
--
2.30.2