[PATCH 05/26] ArmPkg: introduce ASM_FUNC, MOV32/MOV64 and ADRL/LDRL macros

[Ard Biesheuvel <ard.biesheuvel@linaro.org>]

This introduces the ASM_FUNC() macro to annotate function entry points
in assembler files. This allows us to add additional metadata that
marks a function entry point as a function, and allows us to emit
a .section directive for each function, which makes it possible for
the linker to drop unreferenced code.

In addition, introduce a couple of utility macros that we can use to
clean up the code.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
 ArmPkg/Include/AsmMacroIoLib.h   | 23 ++++++++++++++++++++
 ArmPkg/Include/AsmMacroIoLibV8.h | 20 ++++++++++++++++-
 2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/ArmPkg/Include/AsmMacroIoLib.h b/ArmPkg/Include/AsmMacroIoLib.h
index 551b87803d19..fb73ea9a4694 100644
--- a/ArmPkg/Include/AsmMacroIoLib.h
+++ b/ArmPkg/Include/AsmMacroIoLib.h
@@ -3,6 +3,7 @@
 
   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   Copyright (c) 2011-2012, ARM Ltd. All rights reserved.<BR>
+  Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -51,4 +52,26 @@
 
 #endif
 
+#define _ASM_FUNC(Name, Section)    \
+  .global   Name                  ; \
+  .section  #Section, "ax"        ; \
+  .type     Name, %function       ; \
+  Name:
+
+#define ASM_FUNC(Name)            _ASM_FUNC(ASM_PFX(Name), .text. ## Name)
+
+#define MOV32(Reg, Val)                       \
+  movw      Reg, #(Val) & 0xffff            ; \
+  movt      Reg, #(Val) >> 16
+
+#define ADRL(Reg, Sym)                        \
+  movw      Reg, #:lower16:(Sym) - (. + 16) ; \
+  movt      Reg, #:upper16:(Sym) - (. + 12) ; \
+  add       Reg, Reg, pc
+
+#define LDRL(Reg, Sym)                        \
+  movw      Reg, #:lower16:(Sym) - (. + 16) ; \
+  movt      Reg, #:upper16:(Sym) - (. + 12) ; \
+  ldr       Reg, [pc, Reg]
+
 #endif
diff --git a/ArmPkg/Include/AsmMacroIoLibV8.h b/ArmPkg/Include/AsmMacroIoLibV8.h
index 37fa255f842e..e9285f78e7d6 100644
--- a/ArmPkg/Include/AsmMacroIoLibV8.h
+++ b/ArmPkg/Include/AsmMacroIoLibV8.h
@@ -3,6 +3,7 @@
 
   Copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
   Portions copyright (c) 2011 - 2014, ARM Ltd. All rights reserved.<BR>
+  Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
 
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -71,5 +72,22 @@
 
 #endif // __GNUC__
 
-#endif // __MACRO_IO_LIBV8_H__
+#define _ASM_FUNC(Name, Section)    \
+  .global   Name                  ; \
+  .section  #Section, "ax"        ; \
+  .type     Name, %function       ; \
+  Name:
+
+#define ASM_FUNC(Name)            _ASM_FUNC(ASM_PFX(Name), .text. ## Name)
+
+#define MOV32(Reg, Val)                   \
+  movz      Reg, (Val) >> 16, lsl #16   ; \
+  movk      Reg, (Val) & 0xffff
 
+#define MOV64(Reg, Val)                             \
+  movz      Reg, (Val) >> 48, lsl #48             ; \
+  movk      Reg, ((Val) >> 32) & 0xffff, lsl #32  ; \
+  movk      Reg, ((Val) >> 16) & 0xffff, lsl #16  ; \
+  movk      Reg, (Val) & 0xffff
+
+#endif // __MACRO_IO_LIBV8_H__
-- 
2.7.4