Olivier Martin b4e53e389d ArmPkg/ArmSmcLib: Fixed SMC helper functions
The SMC helper functions were buggy as they were assuming that
the values in x1-x7 registers were preserved across an SMC call,
which is not the case.  This patch fixes this issue.

It also simplifies the code by providing only 1 version of the SMC
helper function.  We used to have 4 versions depending on the number
of arguments.  The problem with this approach was that the number of
arguments also dictated the number of return values, which is
completely unrelated.  E.g. you can have an SMC call that takes
1 argument but returns 4 values.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15748 6f19259b-4bc3-4df7-8a09-765794883524
2014-08-04 14:18:13 +00:00

47 lines
1.1 KiB
C

/** @file
*
* Copyright (c) 2012-2014, ARM Limited. All rights reserved.
*
* This program and the accompanying materials
* are licensed and made available under the terms and conditions of the BSD License
* which accompanies this distribution. The full text of the license may be found at
* http://opensource.org/licenses/bsd-license.php
*
* THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
* WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
*
**/
#ifndef __ARM_SMC_LIB__
#define __ARM_SMC_LIB__
/**
* The size of the SMC arguments are different between AArch64 and AArch32.
* The native size is used for the arguments.
*/
typedef struct {
UINTN Arg0;
UINTN Arg1;
UINTN Arg2;
UINTN Arg3;
UINTN Arg4;
UINTN Arg5;
UINTN Arg6;
UINTN Arg7;
} ARM_SMC_ARGS;
/**
Trigger an SMC call
SMC calls can take up to 7 arguments and return up to 4 return values.
Therefore, the 4 first fields in the ARM_SMC_ARGS structure are used
for both input and output values.
**/
VOID
ArmCallSmc (
IN OUT ARM_SMC_ARGS *Args
);
#endif