TI中文支持网问题现象：使用烧写器对GPMC初始化后可正常boot，拔掉烧写器后不能正常启动。
AM335x的手册中描述，boot时内部ROM code未对所有的GPMC引脚进行配置，只配置A0-A11.
AM437x也存在同样的问题吗？
SYSBOOT[4:0]=00101b
GPMC地址总线使用的引脚
a[11:0] →gpmc_a[11:0]
a[19:12] →dss_data[15:8]
a[23:20] →mmc0_dat[0:3]
a24 →mmc0_clk
a25 →mmc0_cmd
d[15:0] →gpmc_ad[15:0]
AM335x手册中的描述
26.1.8.2.2 Pins Used
The list of device pins that are configured by the ROM in the case of NOR boot mode are as follows.
Please note that all the pins might not be driven at boot time. The decision as to which pins need to be
driven is done based on the type of NOR flash selected. The pins that are not listed below are not
configured by the ROM code and are left at power-on defaults. Specifically, external logic is needed to
isolate the upper address lines (A12–A27) of the NOR flash from the device pins and drive them low
during non-muxed NOR boot. Similarly for Muxed NOR Boot, address lines A16 and above to the memory
are not controlled by the ROM and need to be managed externally during boot to ensure proper
addressing to the all memory signals.
Shine：
AM437x TRM手册里并没有同样的说明。您可以用仿真器跟一下boot过程，看是否有跳转到0x08000000h处执行代码？
processors.wiki.ti.com/…/Debugging_Boot_Issues
user3801207：
回复 Shine:
是将GPMC初始化的代码删除后进行调试吗？
实际进行了Flash的动作波形确认，在上电之初是有从Flash中读数据的过程，大概8ms后再无Flash读的动作。
并且在这个过程中，A12-A27始终为低电平。
Shine：
回复 user3801207:
用上面的方法跟踪boot过程时不需要load gel文件，因为gel文件只有在仿真器调试时才会用，脱机运行时是不用GEl文件的。
