diff options
| author |   Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
|---|---|---|
| committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
| commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
| tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/edk2/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S')
| -rw-r--r-- | roms/edk2/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/roms/edk2/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S b/roms/edk2/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S new file mode 100644 index 000000000..ee265f94b --- /dev/null +++ b/roms/edk2/ArmPkg/Library/ArmSvcLib/AArch64/ArmSvc.S @@ -0,0 +1,43 @@ +//
+// Copyright (c) 2012 - 2020, ARM Limited. All rights reserved.
+//
+// SPDX-License-Identifier: BSD-2-Clause-Patent
+//
+//
+
+.text
+.align 3
+
+GCC_ASM_EXPORT(ArmCallSvc)
+
+ASM_PFX(ArmCallSvc):
+ // Push frame pointer and return address on the stack
+ stp x29, x30, [sp, #-32]!
+ mov x29, sp
+
+ // Push x0 on the stack - The stack must always be quad-word aligned
+ str x0, [sp, #16]
+
+ // Load the SVC arguments values into the appropriate registers
+ ldp x6, x7, [x0, #48]
+ ldp x4, x5, [x0, #32]
+ ldp x2, x3, [x0, #16]
+ ldp x0, x1, [x0, #0]
+
+ svc #0
+ // Prevent speculative execution beyond svc instruction
+ dsb nsh
+ isb
+
+ // Pop the ARM_SVC_ARGS structure address from the stack into x9
+ ldr x9, [sp, #16]
+
+ // Store the SVC returned values into the ARM_SVC_ARGS structure.
+ // A SVC call can return up to 4 values - we do not need to store back x4-x7.
+ stp x0, x1, [x9, #0]
+ stp x2, x3, [x9, #16]
+
+ mov x0, x9
+
+ ldp x29, x30, [sp], #32
+ ret
|