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Sets the processor to Supervisor mode and disables all interrupts
by setting both interrupt mask bits in the new CPSR.
With RealView ICE or RealMonitor, the User stack pointer, r13_USR is
copied to the Supervisor stack pointer, r13_SVC and
the I and F bits in the current CPSR are set,
disabling normal and fast interrupts.
If debugging with RVISS:
r0 is set to zero indicating
that no function is available for returning to User mode
the User mode stack pointer is not copied to the Supervisor stack pointer.
On exit, r0 contains the address of a function
to be called to return to User mode. The function has the following
prototype:
void ReturnToUSR(void)
If EnterSVC is called in User mode, this
routine returns the caller to User mode and restores the interrupt
flags. Otherwise, the action of this routine is undefined.
If entered in User mode, the Supervisor stack is lost as a
result of copying the user stack pointer. The return to User routine
restores r13_SVC to the Supervisor mode stack
value, but this stack must not be used by applications.
After executing the SVC, the current link register is r14_SVC,
not r14_USR. If the value of r14_USR is
required after the call, it must be pushed onto the stack before
the call and popped afterwards, as for a BL function
call.
| Copyright © 2002-2007 ARM Limited. All rights reserved. | ARM DUI 0203H |
| Non-Confidential | |
| PDF version | |
| Home > Semihosting > Semihosting operations > angel_SWIreason_EnterSVC (0x17) |