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| howto:uboot 2010/07/19 17:59 | howto:uboot 2017/09/06 18:38 current | ||
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| ====== U-BOOT Monitor ====== | ====== U-BOOT Monitor ====== | ||
| - | * See also [[http://wiki.dns323.info/hardware:serial|serial connections]]. | + | * See also [[http://dns323.kood.org/hardware:serial|serial connections]]. |
| Line 6: | Line 7: | ||
| * Type the two keys **SPACE** and **1** before the monitor 3 second timeout. | * Type the two keys **SPACE** and **1** before the monitor 3 second timeout. | ||
| + | ===== Enabled Commands ===== | ||
| + | |||
| + | The standard U-Boot on my B1 hardware has the following commands enabled: | ||
| + | |||
| + | Marvell>> ? | ||
| + | ? - alias for 'help' | ||
| + | bootm - boot application image from memory | ||
| + | cp - memory copy | ||
| + | echo - echo args to console | ||
| + | erase - erase FLASH memory | ||
| + | loadb - load binary file over serial line (kermit mode) | ||
| + | md - memory display | ||
| + | printenv- print environment variables | ||
| + | run - run commands in an environment variable | ||
| + | setenv - set environment variables | ||
| + | Marvell>> | ||
| + | |||
| + | It is pretty limited, but is enough to recover a failed firmware installation. | ||
| + | |||
| + | There is mention made of additional commands which may be enabled through setting the environment variable "enaMonExt" to "yes" ("setenv enaMonExt yes" at the U-Boot prompt). Examination of the Marvell sources confirm this variable name, and what it is supposed to do. | ||
| + | |||
| + | Unfortunately, it simply results in the following output for any "advanced" commands: | ||
| + | |||
| + | Marvell>> tftpfs | ||
| + | Unknown command 'FSrun' - try 'help' | ||
| + | Marvell>> blah | ||
| + | Unknown command 'FSrun' - try 'help' | ||
| + | Marvell>> | ||
| + | |||
| + | As you can see, the command is being translated to "FSrun", which indicates that the "enaMonExt" code path is being followed, but unfortunately, the version of U-Boot that I have was compiled without support for the "FSrun" command, which means that this has no meaningful effect on this hardware. | ||
| ===== Exploring U-Boot ===== | ===== Exploring U-Boot ===== | ||
