Re your subject: No, they are not.
In message 1096540775.5348.38.camel@mhpajh5c you wrote:
As I've mentioned, u-boot is running on the board now. However, I've so far failed to get a stand-alone application to run. For instance, when I load hello_world.srec, then check it with iminfo, I get "bad magic number".
What makes you think that a stand-alone application should have a valid header? Did you use mkimage to build it?
Using mkimage -l hello_world.srec, I get 'Bad Magic Number: "hello_world.srec" is no valid image' I get the same result for hello_world (the elf format).
Of course.
Can anyone explain why u-boot is building invalid images?
These are vaid images. They just don't have a U-Boot image header as you didn't add one.
Best regards,
Wolfgang Denk