📄 upgrading_u-boot.html
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html><head> <title></title> <link rel="stylesheet" media="screen" type="text/css" href="./style.css" /> <link rel="stylesheet" media="screen" type="text/css" href="./design.css" /> <link rel="stylesheet" media="print" type="text/css" href="./print.css" /> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /></head><body><a href=start.html>start</a></br><div class="toc"><div class="tocheader toctoggle" id="toc__header">Table of Contents</div><div id="toc__inside"><ul class="toc"><li class="clear"><ul class="toc"><li class="level2"><div class="li"><span class="li"><a href="#upgrading_u-boot" class="toc">Upgrading U-Boot</a></span></div></li><li class="level2"><div class="li"><span class="li"><a href="#downloading_via_ethernet" class="toc">Downloading via Ethernet</a></span></div></li><li class="level2"><div class="li"><span class="li"><a href="#downloading_via_serial" class="toc">Downloading via Serial</a></span></div></li><li class="level2"><div class="li"><span class="li"><a href="#testing_the_recently_downloaded_u-boot" class="toc">Testing the recently downloaded U-Boot</a></span></div></li><li class="level2"><div class="li"><span class="li"><a href="#writing_u-boot_into_parallel_nor_flash" class="toc">Writing U-Boot into Parallel NOR Flash</a></span></div><ul class="toc"><li class="level3"><div class="li"><span class="li"><a href="#erasing_the_flash" class="toc">Erasing the Flash</a></span></div></li></ul></li><li class="level2"><div class="li"><span class="li"><a href="#write_u-boot_into_serial_nor_flash" class="toc">Write U-Boot into Serial NOR flash</a></span></div></li></ul></li></ul></div></div><h2><a name="upgrading_u-boot" id="upgrading_u-boot">Upgrading U-Boot</a></h2><div class="level2"><p>As described in the <a href="compiling_u-boot.html" class="wikilink1" title="compiling_u-boot.html">Compiling U-Boot</a> section, when U-Boot is built it generates the file <code>u鈥慴oot.bin</code>. The file <code>u鈥慴oot.bin</code> allows an older version of U鈥態oot, already loaded on the target system, to be upgraded to the version that created <code>u鈥慴oot.bin</code>. This is very useful because it allows U鈥態oot to be upgraded on the target without having to re-flash the board with a JTAG cable.</p><p><a href="loading_u-boot.html" class="wikilink1" title="loading_u-boot.html">Loading U鈥態oot</a></p><p>After creating the <code>u-boot.bin</code> file, it must be transfered to the target by either Ethernet, or Serial.</p></div><!-- SECTION [1-784] --><h2><a name="downloading_via_ethernet" id="downloading_via_ethernet">Downloading via Ethernet</a></h2><div class="level2"><p> Before U-Boot can be upgraded a TFTP server must be set up on the host computer and the TFTP directory must contain the <code>u鈥慴oot.bin</code> file. Also, U-Boot’s environment variables must be setup to communicate with the TFTP server (see <a href="setting_up_a_tftp_server.html" class="wikilink1" title="setting_up_a_tftp_server.html">Setting up a TFTP Server</a>). Next the <code>u鈥慴oot.bin</code> file must be copied to the target board. To do this, at the U-Boot command prompt type:</p><pre class="code">BOOT> tftp 0x1000000 u-boot.bin</pre><p>This command generates the following output:</p><pre class="code">Filename 'u-boot.bin'.Load Address: 0x1000000Loading: ##########################doneBytes Transfered = 131120 (20030 hex)</pre><p> </p></div><!-- SECTION [785-1651] --><h2><a name="downloading_via_serial" id="downloading_via_serial">Downloading via Serial</a></h2><div class="level2"><p> To load via serial, start the receiver, with the <code>loadb</code> command, and then excape to the terminal program’s send file option, and send the file.</p><pre class="code">BOOT> loadbLoad Address: 0x1000000Loading: ##########################doneBytes Transfered = 131120 (20030 hex)</pre></div><!-- SECTION [1652-1969] --><h2><a name="testing_the_recently_downloaded_u-boot" id="testing_the_recently_downloaded_u-boot">Testing the recently downloaded U-Boot</a></h2><div class="level2"><p> Once the U-boot has been compiled and downloaded to the target, you can test it without erasing and re-programming the flash, by:</p><pre class="code">BOOT> go 0x1000000</pre><p>This will run U-Boot, almost like it was run from flash. Doing this will require you to download the <code>u-boot.bin</code> again, before erasing and storing it into flash.</p></div><!-- SECTION [1970-2353] --><h2><a name="writing_u-boot_into_parallel_nor_flash" id="writing_u-boot_into_parallel_nor_flash">Writing U-Boot into Parallel NOR Flash</a></h2><div class="level2"></div><!-- SECTION [2354-2406] --><h3><a name="erasing_the_flash" id="erasing_the_flash">Erasing the Flash</a></h3><div class="level3"><p> <a href="loading_u-boot.html" class="wikilink1" title="loading_u-boot.html">Loading U鈥態oot</a>.</p><p>Now the flash where the old U鈥態oot is stored must be erased. Before this is done the flash memory sectors must be unprotected. To do this enter the following command:</p><pre class="code">BOOT> protect off all</pre><p>The flash memory can now be erased. To do this enter the following command:</p><pre class="code">BOOT> erase all </pre><p>Erases flash memory. Next the new U-Boot must be written into flash. To do this the new boot flash and the new application flash separately must be written separately. The ranges of these two flash sections are given below:</p><p>Boot Flash 0×20000000 鈥⌨️ 快捷键说明
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