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| 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/SemihostLib/Arm | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/edk2/ArmPkg/Library/SemihostLib/Arm')
| -rw-r--r-- | roms/edk2/ArmPkg/Library/SemihostLib/Arm/GccSemihost.S | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/roms/edk2/ArmPkg/Library/SemihostLib/Arm/GccSemihost.S b/roms/edk2/ArmPkg/Library/SemihostLib/Arm/GccSemihost.S new file mode 100644 index 000000000..d6f81ec2c --- /dev/null +++ b/roms/edk2/ArmPkg/Library/SemihostLib/Arm/GccSemihost.S @@ -0,0 +1,31 @@ +#------------------------------------------------------------------------------
+#
+# Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR>
+#
+# SPDX-License-Identifier: BSD-2-Clause-Patent
+#
+#------------------------------------------------------------------------------
+
+#include <AsmMacroIoLib.h>
+
+/*
+ Semihosting operation request mechanism
+
+ SVC 0x123456 in ARM state (for all architectures)
+ SVC 0xAB in Thumb state (excluding ARMv7-M)
+ BKPT 0xAB for ARMv7-M (Thumb-2 only)
+
+ R0 - operation type
+ R1 - block containing all other parametes
+
+ lr - must be saved as svc instruction will cause an svc exception and write
+ the svc lr register. That happens to be the one we are using, so we must
+ save it or we will not be able to return.
+ */
+ASM_FUNC(GccSemihostCall)
+ stmfd sp!, {lr}
+ svc #0x123456
+ ldmfd sp!, {lr}
+ bx lr
+
+
|