This is a utility library closely modeled after ArmSmcLib, that allows hypervisor call (HVC) instructions to be issued from C code. Change-Id: I5f5c65f83e910ff98dbb2f5b031dad8c4f663daa Contributed-under: TianoCore Contribution Agreement 1.0 Acked-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Olivier Martin <olivier.martin@arm.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16088 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			54 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			54 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| //
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| //  Copyright (c) 2012-2014, ARM Limited. All rights reserved.
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| //  Copyright (c) 2014, Linaro Limited. All rights reserved.
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| //
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| //  This program and the accompanying materials
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| //  are licensed and made available under the terms and conditions of the BSD License
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| //  which accompanies this distribution.  The full text of the license may be found at
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| //  http://opensource.org/licenses/bsd-license.php
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| //
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| //  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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| //  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| //
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| //
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| 
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| .text
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| .align 3
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| .arch_extension virt
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| 
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| GCC_ASM_EXPORT(ArmCallHvc)
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| 
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| ASM_PFX(ArmCallHvc):
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|     push    {r4-r8}
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|     // r0 will be popped just after the HVC call
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|     push    {r0}
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| 
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|     // Load the HVC arguments values into the appropriate registers
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|     ldr     r7, [r0, #28]
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|     ldr     r6, [r0, #24]
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|     ldr     r5, [r0, #20]
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|     ldr     r4, [r0, #16]
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|     ldr     r3, [r0, #12]
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|     ldr     r2, [r0, #8]
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|     ldr     r1, [r0, #4]
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|     ldr     r0, [r0, #0]
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| 
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|     hvc     #0
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| 
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|     // Pop the ARM_HVC_ARGS structure address from the stack into r8
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|     pop     {r8}
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| 
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|     // Load the HVC returned values into the appropriate registers
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|     // A HVC call can return up to 4 values - we do not need to store back r4-r7.
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|     str     r3, [r8, #12]
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|     str     r2, [r8, #8]
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|     str     r1, [r8, #4]
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|     str     r0, [r8, #0]
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| 
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|     mov     r0, r8
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| 
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|     // Restore the registers r4-r8
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|     pop     {r4-r8}
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| 
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|     bx      lr
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