Linux 如何进入uboot命令提示符？
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/13093539/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
How to get into uboot command prompt?
提问by mans
I have a system that booted into Linux using UBOOT. I can see that it is booting when I connect to it via serial port. How can I stop it booting UBOOT and get the UBOOT command prompt?
我有一个使用 UBOOT 启动到 Linux 的系统。当我通过串行端口连接到它时，我可以看到它正在启动。如何停止它启动 UBOOT 并获得 UBOOT 命令提示符？
During boot, I can see the following messages on attached serial terminal:
在启动过程中，我可以在连接的串行终端上看到以下消息：
Security Framework initialized
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
devtmpfs: initialized
TI81XX: Map 0xb3200000 to 0xfe500000 for dram barrier
TI81XX: Map 0x40300000 to 0xfe600000 for sram barrier
omap_voltage_early_init: voltage driver support not added
regulator: core version 0.5
regulator: dummy:
NET: Registered protocol family 16
omap_voltage_domain_lookup: Voltage driver init not yet happened.Faulting!
omap_voltage_add_dev: VDD specified does not exist!
OMAP GPIO hardware version 0.1
OMAP GPIO hardware version 0.1
OMAP GPIO hardware version 0.1
OMAP GPIO hardware version 0.1
Cannot clk_get ck_32
.....
回答by mvp
Normally, u-boot can be interrupted by hitting Escape on serial console during boot.
通常，u-boot 可以通过在启动期间在串行控制台上按 Escape 来中断。
But, it really depends on how u-boot was configured by OEM. Also, keep in mind that there is no such thing as single coherent u-boot - it has at least 40 semi-official forks and god knows how many unofficial ones. It is possible to configure u-boot such that you cannot really interrupt boot process, but it is not very common.
但是，这实际上取决于 OEM 配置 u-boot 的方式。另外，请记住，没有单一连贯的 u-boot 之类的东西 - 它至少有 40 个半官方分叉，天知道有多少非官方分叉。可以将 u-boot 配置为不能真正中断启动过程，但这并不常见。
If that does not work, if could be that your serial terminal program is not configured to the same settings as was provisioned by OEM - speed, parity, flow control, etc. I would suggest trying to change terminal program serial speed from 115200 bps (most common) all way down to 9600 (not common, but possible), and changing flow control to None, Xon/Xoff, CTS/RTS. If nothing works, you may want to use another serial cable - some systems may require NULL-modem cable. Good luck!
如果这不起作用，可能是因为您的串行终端程序未配置为与 OEM 提供的设置相同的设置 - 速度、奇偶校验、流量控制等。我建议尝试将终端程序串行速度从 115200 bps（最常见）一直下降到 9600（不常见，但可能），并将流量控制更改为无、Xon/Xoff、CTS/RTS。如果没有任何效果，您可能需要使用另一条串行电缆 - 某些系统可能需要 NULL 调制解调器电缆。祝你好运！
