Specifications
# dropbearkey -t rsa -f /etc/dropbear/dropbear_rsa_host_key
Will output 1024 bit rsa secret key to '/etc/dropbear/dropbear_rsa_host_key'
Generating key, this may take a while...
Public key portion is:
ssh-rsa ...
Fingerprint: md5 ...
# dropbearkey -t dss -f /etc/dropbear/dropbear_dss_host_key
Will output 1024 bit dss secret key to '/etc/dropbear/dropbear_dss_host_key'
Generating key, this may take a while...
Public key portion is:
ssh-dss ...
Fingerprint: md5 ...
Then you can start the dropbear daemon:
# dropbear
Now you should be able to access the target system through SSH.
14.2. U-Boot
14.2.1. Can U-Boot be configured such that it can
be started in RAM?
Question:
I don't want to erase my flash memory because I'm not sure if my new U-Boot image will work. Is it
possible to configure U-Boot such that I can load it into RAM instead of flash, and start it from my
old boot loader?
Answer:
No. (Unless you're using a Blackfin processor, but you probably aren't.)
Question:
But I've been told it is possible??
Answer:
Well, yes. Of course this is possible. This is software, so everything is possible. But it is difficult,
unsupported, and fraught with peril. You are on your own if you choose to do it. And it will not help
you to solve your problem.
Question:
Why?
Answer:
U-Boot expects to see a virgin CPU, i. e. the CPU state must match what you see if the processor
starts executing the first instructions when it comes out of reset. If you want to start U-Boot from
another boot loader, you must disable a lot of code, i. e. all initialization parts that already have been
performed by this other boot loader, like setting up the memory controller, initializing the SDRAM,
initializing the serial port, setting up a stack frame etc. Also you must disable the relocation to RAM
and adjust the link addresses etc.
This requires a lot of experience with U-Boot, and the fact that you had to ask if this can be done
means that you are not in a position to do this.
The code you have to disable contains the most critical parts in U-Boot, i. e. these are the areas where
14.2.1. Can U-Boot be configured such that it can be started in RAM? 159