in arm7tdmi, suppose instruction is being executed and at same time FIQ and IRQ both occur at same time.now according to priority FIQ will be handled then IRQ but my question is that how it will handled IRQ after return from FIQ
i means what will be process done at return of FIQ and how control will be transferred to IRQ handler after return statement of FIQ handler ?
example :
address => instruction
0x00000100 : MOV R0,R1
0x00000104 : MOV R0,R1
==> 0x00000108 : MOV R0,R1 ; suppose this is instruction being executed and FIQ and IRQ are raised at same time
0x00000110 : MOV R0,R1
0x00000114 : MOV R0,R1
0x00000118 : MOV R0,R1
Though I don't have a RasPi myself, I second chrisshore's suggestion. The Raspberry Pi is an excellent platform, which allows you to start from scratch or develop parts of your system under Linux and when you've finished enough components, you can put them together in a 'stand-alone' O/S.
In addition to the above, you might benefit from getting a WD PiDrive, which was developed specifically for the Raspberry Pi. -It's no coincidence that it's 314 GB either.
In case your development system is a PC, you could attach the PiDrive there, then move the drive to the Raspberry Pi for booting (or testing modules).