Fast boot for lx2160 in adas

[#1]

FAST BOOT FOR lx2160 IN adas

•Objective

To speed ​​​​up bringup of LX2 chip-based systems

•Pain Points to Address

The bringup time is much longer than 3s, which is very sensitive in ADAS systems or time-sensitive systems.

•Value Proposition / Key Features

The guide can help customers shorten uboot time from 5s to less than 1.5s, saving more than 70% bootup time.

•Deliverables

Demo based on LX2160ARDB board.

Reference codes and patches.

Guide for Fast boot document.

Fast boot 广泛用于嵌入式设备，现以lx2160ardb板为例进行相关探索。
启动流程：

优化思路：

1.适当提高FSPI时钟速率

diff --git a/lx2160asi/flexspi_divisor_32.rcw b/lx2160asi/flexspi_divisor_32.rcw
index 422139c..0f8d5c9 100644
--- a/lx2160asi/flexspi_divisor_32.rcw
+++ b/lx2160asi/flexspi_divisor_32.rcw
@@ -7,8 +7,10 @@
  * Modify FlexSPICR1 register, to increase FlexSPI clock closer to 50MHz,
  * with divisor value as 32.
  *      => 750 * 2 / 32 ==> 46.875MHz
+ *write 0x1e00900,0x00000013
+ * 0f -12    =125M
  */

 .pbi
-write 0x1e00900,0x00000013
+write 0x1e00900,0x0f
 .end
​

2.关键路径优化

1. 固化spd参数
   

   

2. 固化ddrc参数
   
3. BL33 裁剪
   

详细patch和测试结果参考附件。