<p>Barnali Sarkar has uploaded this change for <strong>review</strong>.</p><p><a href="https://review.coreboot.org/20236">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">cpu/intel/microcode: Authentication of microcode update<br><br>After a microcode update is triggered, add a check to read<br>back the signature after the update.<br>If the signature is 0, microcode update hasn't occured<br>successully. In that case, asserting.<br><br>Change-Id: Ib5b509bbdac04fb5c5fd3ded9f1db5590b8beab4<br>Signed-off-by: Barnali Sarkar <barnali.sarkar@intel.com><br>---<br>M src/cpu/intel/microcode/microcode.c<br>1 file changed, 7 insertions(+), 0 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://review.coreboot.org:29418/coreboot refs/changes/36/20236/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">diff --git a/src/cpu/intel/microcode/microcode.c b/src/cpu/intel/microcode/microcode.c<br>index 59c3b8a..f827960 100644<br>--- a/src/cpu/intel/microcode/microcode.c<br>+++ b/src/cpu/intel/microcode/microcode.c<br>@@ -16,6 +16,7 @@<br> <br> /* Microcode update for Intel PIII and later CPUs */<br> <br>+#include <assert.h><br> #include <stdint.h><br> #include <stddef.h><br> #if !defined(__ROMCC__)<br>@@ -103,6 +104,12 @@<br>      msr.lo = (unsigned long)m + sizeof(struct microcode);<br>         msr.hi = 0;<br>   wrmsr(0x79, msr);<br>+    /*<br>+    * Read back the BIOS_SIGN_ID msr to authenticate the update.<br>+         * If value returned is 0, then the update is not successfull.<br>+        * Thus asserting.<br>+    */<br>+  assert(read_microcode_rev());<br> <br> #if !defined(__ROMCC__)<br>    printk(BIOS_DEBUG, "microcode: updated to revision "<br></pre><p>To view, visit <a href="https://review.coreboot.org/20236">change 20236</a>. To unsubscribe, visit <a href="https://review.coreboot.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://review.coreboot.org/20236"/><meta itemprop="name" content="View Change"/></div></div>

<div style="display:none"> Gerrit-Project: coreboot </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>
<div style="display:none"> Gerrit-Change-Id: Ib5b509bbdac04fb5c5fd3ded9f1db5590b8beab4 </div>
<div style="display:none"> Gerrit-Change-Number: 20236 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: Barnali Sarkar <barnali.sarkar@intel.com> </div>
<div style="display:none"> Gerrit-Reviewer: Subrata Banik <subrata.banik@intel.com> </div>
<div style="display:none"> Gerrit-Reviewer: dhaval v sharma <dhaval.v.sharma@intel.com> </div>