title: Writing to NVRAM from U-boot shell mode
body: <p>Hardware device with embedded system. NVRAM is corrupted, and I want replace nvram. Is it possible to update NVRAM from within U-boot shell mode?
  U-boot provide option to upgrade firmware, u-boot, uimage and other components: two examples from U-boot code:</p>
  
  <pre><code>update_uboot=tftpboot 0x80000100 u-boot.bin &amp;&amp; protect off 0x48000000 +${filesize} &amp;&amp; erase 0x48000000 +${filesize} &amp;&amp; sleep ${sdelay} &amp;&amp; cp.b ${fileaddr} 0x48000000 ${filesize} &amp;&amp; protect on 0x48000000 +${filesize}
  
  update_uimage=tftpboot 0x80000100 uImage &amp;&amp; protect off ${UBFIADDR1} +${filesize} &amp;&amp; erase ${UBFIADDR1} +${filesize} &amp;&amp; sleep ${sdelay} &amp;&amp; cp.b ${fileaddr} ${UBFIADDR1} ${filesize} &amp;&amp; protect on ${UBFIADDR1} +${filesize}
  </code></pre>
  
  <p>There is no any directions or tips for NVRAM upgrade in U-boot code. The nvram.bin offset address is specified in u-boot settings, is it possible to replace NVRAM from U-boot shell mode? How to unlock NVRAM for writing from within u-boot shell? I tried write to NVRAM, but it not allows.</p>
  
  <p>Here is U-boot <a href="http://pastebin.com/raw.php?i=W6mnfUaq" rel="nofollow">dump</a> with all commands inside.
  Spansion Serial Flash S25FL064A</p>