What do the contents of the general purpose registers contain?

I included the iOS tag, but I'm running in the simulator on a Core i7 MacBook Pro (x86-64, right?), so I think that's immaterial.

I'm currently debugging a crash in Flurry's video ads. I have a breakpoint set on Objective-C exceptions. When the breakpoint is hit I am in objc_msgSend. The callstack contains a mix of private Flurry and iOS methods, nothing public and nothing that I've written. Calling register read from the objc_msgSend stack frame outputs the following:

(lldb) register readGeneral Purpose Registers:       eax = 0x1ac082d0       ebx = 0x009600b5  "spaceWillDismiss:interstitial:"       ecx = 0x03e2cddb  "makeKeyAndVisible"       edx = 0x0000003f       edi = 0x0097c6f3  "removeWindow"       esi = 0x00781e65  App`-[FlurryAdViewController removeWindow] + 12       ebp = 0xbfffd608       esp = 0xbfffd5e8        ss = 0x00000023    eflags = 0x00010202  App`-[FeedTableCell setupVisibleCommentAndLike] + 1778 at FeedTableCell.m:424       eip = 0x049bd09b  libobjc.A.dylib`objc_msgSend + 15        cs = 0x0000001b        ds = 0x00000023        es = 0x00000023        fs = 0x00000000        gs = 0x0000000f

I've got a few questions about this output.

• I assumed $ebx contains the selector that caused the crash and $edi is the last executing method. Is that the case?
• $eip is where I crashed. Is that usually the case?
• $eflags references an instance method that, as far as I know, has nothing to do with this crash. What is that?
• Is there any other information I can pry out of these registers?