X-Git-Url: http://pilppa.org/gitweb/?a=blobdiff_plain;f=Documentation%2Foops-tracing.txt;h=7f60dfe642caf9a65421f49b3cf9c342b79705dd;hb=024cf53089f7c8e58934407f07ca2a7b5bed3b06;hp=9f30ac6ca47b4caa382a281523b27a8abc95f541;hpb=cbc749518235b0f1dacb867c8c25059a1b876276;p=linux-2.6-omap-h63xx.git

diff --git a/Documentation/oops-tracing.txt b/Documentation/oops-tracing.txt
index 9f30ac6ca47..7f60dfe642c 100644
--- a/Documentation/oops-tracing.txt
+++ b/Documentation/oops-tracing.txt
@@ -32,17 +32,18 @@ the disk is not available then you have three options :-
     has restarted.  Messy but it is the only option if you have not
     planned for a crash. Alternatively, you can take a picture of
     the screen with a digital camera - not nice, but better than
-    nothing.
+    nothing.  If the messages scroll off the top of the console, you
+    may find that booting with a higher resolution (eg, vga=791)
+    will allow you to read more of the text. (Caveat: This needs vesafb,
+    so won't help for 'early' oopses)
 
 (2) Boot with a serial console (see Documentation/serial-console.txt),
     run a null modem to a second machine and capture the output there
     using your favourite communication program.  Minicom works well.
 
-(3) Patch the kernel with one of the crash dump patches.  These save
-    data to a floppy disk or video rom or a swap partition.  None of
-    these are standard kernel patches so you have to find and apply
-    them yourself.  Search kernel archives for kmsgdump, lkcd and
-    oops+smram.
+(3) Use Kdump (see Documentation/kdump/kdump.txt),
+    extract the kernel ring buffer from old memory with using dmesg
+    gdbmacro in Documentation/kdump/gdbmacros.txt.
 
 
 Full Information
@@ -85,6 +86,20 @@ stuff are the values reported by the Oops - you can just cut-and-paste
 and do a replace of spaces to "\x" - that's what I do, as I'm too lazy 
 to write a program to automate this all).
 
+Alternatively, you can use the shell script in scripts/decodecode.
+Its usage is:  decodecode < oops.txt
+
+The hex bytes that follow "Code:" may (in some architectures) have a series
+of bytes that precede the current instruction pointer as well as bytes at and
+following the current instruction pointer.  In some cases, one instruction
+byte or word is surrounded by <> or (), as in "<86>" or "(f00d)".  These
+<> or () markings indicate the current instruction pointer.  Example from
+i386, split into multiple lines for readability:
+
+Code: f9 0f 8d f9 00 00 00 8d 42 0c e8 dd 26 11 c7 a1 60 ea 2b f9 8b 50 08 a1
+64 ea 2b f9 8d 34 82 8b 1e 85 db 74 6d 8b 15 60 ea 2b f9 <8b> 43 04 39 42 54
+7e 04 40 89 42 54 8b 43 04 3b 05 00 f6 52 c0
+
 Finally, if you want to see where the code comes from, you can do
 
 	cd /usr/src/linux
@@ -233,6 +248,11 @@ characters, each representing a particular tainted value.
   6: 'B' if a page-release function has found a bad page reference or
      some unexpected page flags.
 
+  7: 'U' if a user or user application specifically requested that the
+     Tainted flag be set, ' ' otherwise.
+
+  8: 'D' if the kernel has died recently, i.e. there was an OOPS or BUG.
+
 The primary reason for the 'Tainted: ' string is to tell kernel
 debuggers if this is a clean kernel or if anything unusual has
 occurred.  Tainting is permanent: even if an offending module is