X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/4d15aeb193b2c68f1d38666c317f8d3734f5f083..5ba3f43ea354af8ad55bea84372a2bc834d8757c:/osfmk/arm/asm.h

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+/*
+ * Copyright (c) 2007 Apple Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ *
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+/*
+ * @OSF_COPYRIGHT@
+ */
+/* 
+ * Mach Operating System
+ * Copyright (c) 1991,1990,1989 Carnegie Mellon University
+ * All Rights Reserved.
+ * 
+ * Permission to use, copy, modify and distribute this software and its
+ * documentation is hereby granted, provided that both the copyright
+ * notice and this permission notice appear in all copies of the
+ * software, derivative works or modified versions, and any portions
+ * thereof, and that both notices appear in supporting documentation.
+ * 
+ * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
+ * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
+ * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
+ * 
+ * Carnegie Mellon requests users of this software to return to
+ * 
+ *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
+ *  School of Computer Science
+ *  Carnegie Mellon University
+ *  Pittsburgh PA 15213-3890
+ * 
+ * any improvements or extensions that they make and grant Carnegie Mellon
+ * the rights to redistribute these changes.
+ */
+
+#ifndef	_ARM_ASM_H_
+#define	_ARM_ASM_H_
+
+#include <arm/arch.h>
+
+#define FRAME	pushl %ebp; movl %esp, %ebp
+#define EMARF	leave
+
+
+/* There is another definition of ALIGN for .c sources */
+#ifdef ASSEMBLER
+#define ALIGN 2
+#endif /* ASSEMBLER */
+
+#ifndef FALIGN
+#define FALIGN ALIGN
+#endif
+
+#define LB(x,n) n
+#if	__STDC__
+#ifndef __NO_UNDERSCORES__
+#define	LCL(x)	L ## x
+#define EXT(x) _ ## x
+#define LEXT(x) _ ## x ## :
+#else
+#define	LCL(x)	.L ## x
+#define EXT(x) x
+#define LEXT(x) x ## :
+#endif
+#define LBc(x,n) n ## :
+#define LBb(x,n) n ## b
+#define LBf(x,n) n ## f
+#else /* __STDC__ */
+#ifndef __NO_UNDERSCORES__
+#define LCL(x) L/**/x
+#define EXT(x) _/**/x
+#define LEXT(x) _/**/x/**/:
+#else /* __NO_UNDERSCORES__ */
+#define	LCL(x)	.L/**/x
+#define EXT(x) x
+#define LEXT(x) x/**/:
+#endif /* __NO_UNDERSCORES__ */
+#define LBc(x,n) n/**/:
+#define LBb(x,n) n/**/b
+#define LBf(x,n) n/**/f
+#endif /* __STDC__ */
+
+#define String	.asciz
+#define Value	.word
+#define Times(a,b) (a*b)
+#define Divide(a,b) (a/b)
+
+#if 0 /* TOTOJK */
+#ifdef __ELF__
+#define ELF_FUNC(x)	.type x,@function
+#define ELF_DATA(x)	.type x,@object
+#define ELF_SIZE(x,s)	.size x,s
+#else
+#define ELF_FUNC(x)
+#define ELF_DATA(x)
+#define ELF_SIZE(x,s)
+#endif
+#else
+#define ELF_FUNC(x)
+#define ELF_DATA(x)
+#define ELF_SIZE(x,s)
+#endif /* TODOJK */
+
+#define	Entry(x)	.globl EXT(x); ELF_FUNC(EXT(x)); .align FALIGN; LEXT(x)
+#define	ENTRY(x)	Entry(x) MCOUNT
+#define	ENTRY2(x,y)	.globl EXT(x); .globl EXT(y); \
+			ELF_FUNC(EXT(x)); ELF_FUNC(EXT(y)); \
+			.align FALIGN; LEXT(x); LEXT(y) \
+			MCOUNT
+#if __STDC__
+#define	ASENTRY(x) 	.globl x; .align FALIGN; x ## : ELF_FUNC(x) MCOUNT
+#else
+#define	ASENTRY(x) 	.globl x; .align FALIGN; x: ELF_FUNC(x) MCOUNT
+#endif /* __STDC__ */
+
+#define	DATA(x)		.globl EXT(x); ELF_DATA(EXT(x)); .align ALIGN; LEXT(x)
+
+#define End(x)		ELF_SIZE(x,.-x)
+#define END(x)		End(EXT(x))
+#define ENDDATA(x)	END(x)
+#define Enddata(x)	End(x)
+
+#ifdef ASSEMBLER
+
+#define MCOUNT
+
+#else /* NOT ASSEMBLER */
+
+/* These defines are here for .c files that wish to reference global symbols
+ * within __asm__ statements. 
+ */
+#ifndef __NO_UNDERSCORES__
+#define CC_SYM_PREFIX "_"
+#else
+#define CC_SYM_PREFIX ""
+#endif /* __NO_UNDERSCORES__ */
+#endif /* ASSEMBLER */
+
+#ifdef ASSEMBLER
+
+#if defined (_ARM_ARCH_4T)
+# define RET    bx      lr
+# define RETeq  bxeq    lr
+# define RETne  bxne    lr
+# ifdef __STDC__
+#  define RETc(c) bx##c lr
+# else
+#  define RETc(c) bx/**/c       lr
+# endif
+#else
+# define RET    mov     pc, lr
+# define RETeq  moveq   pc, lr
+# define RETne  movne   pc, lr
+# ifdef __STDC__
+#  define RETc(c) mov##c        pc, lr
+# else
+#  define RETc(c) mov/**/c      pc, lr
+# endif
+#endif
+
+#if defined (__thumb__)
+/* Provide a PI mechanism for thumb branching. */
+# define BRANCH_EXTERN(x)	ldr	pc, [pc, #-4] ;	\
+				.long	EXT(x)
+#else
+# define BRANCH_EXTERN(x)	b	EXT(x)
+#endif
+
+/*
+ * arg0: Register for thread pointer
+ */
+.macro READ_THREAD
+	mrc p15, 0, $0, c13, c0, 4  /* Read TPIDRPRW */
+.endmacro
+
+
+/* Macros for loading up addresses that are external to the .s file.
+ * LOAD_ADDR:  loads the address for (label) into (reg). Not safe for
+ *   loading to the PC.
+ * LOAD_ADDR_PC:  Variant for loading to the PC; load the address of (label)
+ *   into the pc.
+ * LOAD_ADDR_GEN_DEF:  The general definition needed to support loading
+ *   a label address.
+ *
+ * Usage:  For any label accessed, we require one (and only one) instance
+ *   of LOAD_ADDR_GEN_DEF(label).
+ * 
+ * Example:
+ *   LOAD_ADDR(r0, arm_init)
+ *   LOAD_ADDR(lr, arm_init_cpu)
+ *   LOAD_ADDR_PC(arm_init)
+ *   ...
+ *
+ *   LOAD_ADDR_GEN_DEF(arm_init)
+ *   LOAD_ADDR_GEN_DEF(arm_init_cpu)
+ */
+
+#if SLIDABLE
+/* Definitions for a position dependent kernel using non-lazy pointers.
+ */
+
+/* TODO: Make this work with thumb .s files. */
+#define PC_INC	0x8
+
+/* We need wrapper macros in order to ensure that __LINE__ is expanded.
+ *
+ * There is some small potential for duplicate labels here, but because
+ *   we do not export the generated labels, it should not be an issue.
+ */
+
+#define GLUE_LABEL_GUTS(label, tag) L_##label##_##tag##_glue
+#define GLUE_LABEL(label, tag) GLUE_LABEL_GUTS(label, tag)
+
+#define LOAD_ADDR(reg, label)                                                                   \
+	movw	reg, :lower16:(label##$non_lazy_ptr - (GLUE_LABEL(label, __LINE__) + PC_INC)) ; \
+	movt	reg, :upper16:(label##$non_lazy_ptr - (GLUE_LABEL(label, __LINE__) + PC_INC)) ; \
+GLUE_LABEL(label, __LINE__): ;                                                                  \
+	ldr	reg, [pc, reg]
+
+/* Designed with the understanding that directly branching to thumb code
+ *   is unreliable; this should allow for dealing with __thumb__ in
+ *   assembly; the non-thumb variant still needs to provide the glue label
+ *   to avoid failing to build on undefined symbols.
+ *
+ * TODO: Make this actually use a scratch register; this macro is convenient
+ *   for translating (ldr pc, [?]) to a slidable format without the risk of
+ *   clobbering registers, but it is also wasteful.
+ */
+#if defined(__thumb__)
+#define LOAD_ADDR_PC(label)    \
+	stmfd	sp!, { r0 } ;  \
+	stmfd	sp!, { r0 } ;  \
+	LOAD_ADDR(r0, label) ; \
+	str	r0, [sp, #4] ; \
+	ldmfd	sp!, { r0 } ;  \
+	ldmfd	sp!, { pc }
+#else
+#define LOAD_ADDR_PC(label) \
+	b	EXT(label)
+#endif
+
+#define LOAD_ADDR_GEN_DEF(label)                                   \
+	.section __DATA,__nl_symbol_ptr,non_lazy_symbol_pointers ; \
+	.align 2 ;                                                 \
+label##$non_lazy_ptr: ;                                            \
+	.indirect_symbol	EXT(label) ;                       \
+	.long			0
+
+#else /* !SLIDABLE */
+
+/* Definitions for a position dependent kernel */
+#define LOAD_ADDR(reg, label)  \
+	ldr	reg, L_##label
+
+#if defined(__thumb__)
+#define LOAD_ADDR_PC(label)   \
+	ldr	pc, L_##label
+#else
+#define LOAD_ADDR_PC(label) \
+	b	EXT(label)
+#endif
+
+#define LOAD_ADDR_GEN_DEF(label)  \
+	.text ;                   \
+	.align 2 ;                \
+L_##label: ;                      \
+	.long	EXT(label)
+
+#endif /* SLIDABLE */
+
+/* The linker can deal with branching from ARM to thumb in unconditional
+ *   branches, but not in conditional branches.  To support this in our
+ *   assembly (which allows us to build xnu without -mno-thumb), use the
+ *   following macros for branching conditionally to external symbols.
+ *   These macros are used just like the corresponding conditional branch
+ *   instructions.
+ */
+
+#define SHIM_LABEL_GUTS(line_num) L_cond_extern_##line_num##_shim
+#define SHIM_LABEL(line_num) SHIM_LABEL_GUTS(line_num)
+
+#define COND_EXTERN_BEQ(label)         \
+	bne	SHIM_LABEL(__LINE__) ; \
+	b	EXT(label) ;           \
+SHIM_LABEL(__LINE__):
+
+#define COND_EXTERN_BLNE(label)        \
+	beq	SHIM_LABEL(__LINE__) ; \
+	bl	EXT(label) ;           \
+SHIM_LABEL(__LINE__):
+
+#define COND_EXTERN_BLGT(label)        \
+	ble	SHIM_LABEL(__LINE__) ; \
+	bl	EXT(label) ;           \
+SHIM_LABEL(__LINE__):
+
+#endif /* ASSEMBLER */
+
+#endif /* _ARM_ASM_H_ */