From 9f6eb05d6980e06938cd4611f4b31f60c25162d0 Mon Sep 17 00:00:00 2001
Message-Id: <9f6eb05d6980e06938cd4611f4b31f60c25162d0.1716379730.git.mdw@distorted.org.uk>
From: Mark Wooding <mdw@chiark.greenend.org.uk>
Date: Thu, 26 May 2016 09:26:09 +0100
Subject: [PATCH] base/asm-common.h: Add some slightly cheesy Thumb support.
Organization: Straylight/Edgeware

From: Mark Wooding <mdw@distorted.org.uk>

---
 base/asm-common.h | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/base/asm-common.h b/base/asm-common.h
index 9c2dfb30..bcfa7352 100644
--- a/base/asm-common.h
+++ b/base/asm-common.h
@@ -162,6 +162,11 @@ _where_am_i.\got :
 
 #if CPUFAM_ARM
 
+// ARM/Thumb mode things.  Use ARM by default.
+#define ARM .arm; .L$_pcoff = 8
+#define THUMB .thumb; .L$_pcoff = 4
+	ARM
+
 // Set the function hooks.
 #define FUNC_PREHOOK(_) .balign 4
 #define ENDFUNC_HOOK(name) .ltorg
@@ -190,7 +195,7 @@ _where_am_i.\got :
 	_LIT
 	.balign	4
 .L$_ldgot$\@:
-	.word	_GLOBAL_OFFSET_TABLE_ - .L$_ldgot_pc$\@ - 8
+	.word	_GLOBAL_OFFSET_TABLE_ - .L$_ldgot_pc$\@ - .L$_pcoff
 	_ENDLIT
 #endif
 	.endm
@@ -215,11 +220,16 @@ _where_am_i.\got :
 #if WANT_PIC
 	ldr\cond \reg, .L$_leaextq$\@
 .L$_leaextq_pc$\@:
+	.if	.L$_pcoff == 8
 	ldr\cond \reg, [pc, \reg]
+	.else
+	add\cond \reg, pc
+	ldr\cond \reg, [\reg]
+	.endif
 	_LIT
 	.balign	4
 .L$_leaextq$\@:
-	.word	\addr(GOT_PREL) + (. - .L$_leaextq_pc$\@ - 8)
+	.word	\addr(GOT_PREL) + (. - .L$_leaextq_pc$\@ - .L$_pcoff)
 	_ENDLIT
 #else
 	ldr\cond \reg, =\addr
-- 
[mdw]