Datasheet

Semihosting
ARM DUI0058D Copyright © 1999-2001 ARM Limited. All rights reserved. 5-23
5.4.18 SYS_ERRNO (0x13)
Returns the value of the C library
errno variable associated with the host
implementation of the semihosting SWIs. The
errno variable can be set by a number of
C library semihosted functions, including:
• SYS_REMOVE
• SYS_OPEN
• SYS_CLOSE
• SYS_READ
• SYS_WRITE
• SYS_SEEK.
Whether
errno is set or not, and to what value, is entirely host-specific, except where
the ANSI C standard defines the behavior.
Entry
There are no parameters. Register r1 must be zero.
Return
On exit, r0 contains the value of the C library
errno variable.