Board Manual 23
Intel® IQ80321 I/O Processor E valuation Platform
Getting Started
2.5.2.1 ARM Angel
Angel is one of the debug monit or programs for 80321. It is p rovided in source and binary form with
the ARM Software Developm ent Toolkit. It features:
•Debug capability, including memory inspection, image download and execution,
break-pointing and single step
•CPU and board startup and basic exception handling
•A full ANSI C library, using semihosting (fil e I/O Operation ) to prov ide services fro m the hos t
which are not available on the target
•A full source distribution for users in developing standalo ne applications
Angel interfaces with the ARM Developer Suite in two ways:
•SW Debuggers use the interface library (Remote_A) to communicate with an Angel target
when debugging or executing code.
•Application code uses software interrupt (SWI) calls to request services of Angel either
directly or via the toolkit C library.
2.5.2.1.1 Semihosting (File I/O)
The ARM debuggers support a feature known as semihosting to enable a target system which does
not support various features required by the ANSI C library to u se the features of the host instead. A
simple example of this is the use of a host “window” to p rovide a system console, to which the output
of printf(), etc..., can be written.
Semihosting is supported in Angel using a set of SWI ca lls which the ARM C library uses messages
over the CLIB channel of the target<=>host link, and appropriate code in the host library
(Remote_A.dll under Windows) which interprets and executes these requests.
For information on the SWI calls, see the ARM SDT Refe rence Manual (DUI 0041B) s ection 8.3:
Angel C Library Support (SW Is)