Merged mcb30-realmode-redesign back to HEAD

1 files changed, 186 insertions, 0 deletions

diff --git a/src/arch/i386/include/librm.h b/src/arch/i386/include/librm.h
new file mode 100644
index 00000000..16bfc089
--- /dev/null
+++ b/src/arch/i386/include/librm.h
@@ -0,0 +1,186 @@
+#ifndef LIBRM_H
+#define LIBRM_H
+
+/* Drag in protected-mode segment selector values */
+#include "virtaddr.h"
+#include "realmode.h"
+
+#ifndef ASSEMBLY
+
+#include "stddef.h"
+#include "string.h"
+
+/*
+ * Data structures and type definitions
+ *
+ */
+
+/* Real-mode call parameter block, as passed to real_call */
+struct real_call_params {
+	struct i386_seg_regs;
+	struct i386_regs;
+	segoff_t rm_code;
+	segoff_t reserved;
+} PACKED;
+
+/* Current location of librm in base memory */
+extern char *installed_librm;
+
+/* Start and size of our source copy of librm (i.e. the one that we
+ * can install by copying it to base memory and setting
+ * installed_librm)
+ */
+extern char librm[];
+extern size_t _librm_size[];
+
+/* Linker symbols for offsets within librm.  Other symbols should
+ * almost certainly not be referred to from C code.
+ */
+extern void (*_real_to_prot[]) ( void );
+extern void (*_prot_to_real[]) ( void );
+extern void (*_prot_call[]) ( void );
+extern void (*_real_call[]) ( void );
+extern segoff_t _rm_stack[];
+extern uint32_t _pm_stack[];
+extern char _librm_ref_count[];
+
+/* Symbols within current installation of librm */
+#define LIBRM_VAR( sym ) \
+	( * ( ( typeof ( * _ ## sym ) * ) \
+	      & ( installed_librm [ (int) _ ## sym ] ) ) )
+#define LIBRM_FN( sym ) \
+	 ( ( typeof ( * _ ## sym ) ) \
+	      & ( installed_librm [ (int) _ ## sym ] ) )
+#define LIBRM_CONSTANT( sym ) \
+	( ( typeof ( * _ ## sym ) ) ( _ ## sym ) )
+#define inst_real_to_prot	LIBRM_FN ( real_to_prot )
+#define inst_prot_to_real	LIBRM_FN ( prot_to_real )
+#define inst_prot_call		LIBRM_FN ( prot_call )
+#define inst_real_call		LIBRM_FN ( real_call )
+#define inst_rm_stack		LIBRM_VAR ( rm_stack )
+#define inst_pm_stack		LIBRM_VAR ( pm_stack )
+#define inst_librm_ref_count	LIBRM_VAR ( librm_ref_count )
+#define librm_size		LIBRM_CONSTANT ( librm_size )
+
+/* Functions that librm expects to be able to link to.  Included here
+ * so that the compiler will catch prototype mismatches.
+ */
+extern void _phys_to_virt ( void );
+extern void _virt_to_phys ( void );
+extern void gateA20_set ( void );
+
+/*
+ * librm_mgmt: functions for manipulating base memory and executing
+ * real-mode code.
+ *
+ * Full API documentation for these functions is in realmode.h.
+ *
+ */
+
+/* Macro for obtaining a physical address from a segment:offset pair. */
+#define VIRTUAL(x,y) ( phys_to_virt ( ( ( x ) << 4 ) + ( y ) ) )
+
+/* Copy to/from base memory */
+static inline void copy_to_real_librm ( uint16_t dest_seg, uint16_t dest_off,
+					void *src, size_t n ) {
+	memcpy ( VIRTUAL ( dest_seg, dest_off ), src, n );
+}
+static inline void copy_from_real_librm ( void *dest,
+					  uint16_t src_seg, uint16_t src_off,
+					  size_t n ) {
+	memcpy ( dest, VIRTUAL ( src_seg, src_off ), n );
+}
+#define put_real_librm( var, dest_seg, dest_off )			      \
+	do {								      \
+		* ( ( typeof(var) * ) VIRTUAL ( dest_seg, dest_off ) ) = var; \
+	} while ( 0 )
+#define get_real_librm( var, src_seg, src_off )				      \
+	do {								      \
+		var = * ( ( typeof(var) * ) VIRTUAL ( src_seg, src_off ) ); \
+	} while ( 0 )
+#define copy_to_real copy_to_real_librm
+#define copy_from_real copy_from_real_librm
+#define put_real put_real_librm
+#define get_real get_real_librm
+
+/* Copy to/from real-mode stack */
+extern uint16_t copy_to_rm_stack ( void *data, size_t size );
+extern void remove_from_rm_stack ( void *data, size_t size );
+
+/* Place/remove parameter on real-mode stack in a way that's
+ * compatible with libkir
+ */
+#define BASEMEM_PARAMETER_INIT_LIBRM( param ) \
+	copy_to_rm_stack ( & ( param ), sizeof ( param ) )
+#define BASEMEM_PARAMETER_DONE_LIBRM( param ) \
+	remove_from_rm_stack ( & ( param ), sizeof ( param ) )
+#define BASEMEM_PARAMETER_INIT BASEMEM_PARAMETER_INIT_LIBRM
+#define BASEMEM_PARAMETER_DONE BASEMEM_PARAMETER_DONE_LIBRM
+
+/* REAL_FRAGMENT: Declare and define a real-mode code fragment in .text16 */
+#define	REAL_FRAGMENT( name, asm_code_str )				\
+	extern void name ( void );					\
+	extern char name ## _size[];					\
+	__asm__ __volatile__ (						\
+		".section \".text16\"\n\t"				\
+		".code16\n\t"						\
+		".arch i386\n\t"					\
+		#name ":\n\t"						\
+		asm_code_str "\n\t"					\
+		"lret\n\t"						\
+		#name "_end:\n\t"					\
+		".equ " #name "_size, " #name "_end - " #name "\n\t"	\
+		".code32\n\t"						\
+		".previous\n\t"						\
+		: :							\
+	)
+#define FRAGMENT_SIZE( fragment ) ( (size_t) fragment ## _size )
+
+/* REAL_CALL: call a real-mode routine via librm */
+#define OUT_CONSTRAINTS(...) __VA_ARGS__
+#define IN_CONSTRAINTS(...) "m" ( __routine ), ## __VA_ARGS__
+#define CLOBBER(...) __VA_ARGS__
+#define REAL_CALL( routine, num_out_constraints, out_constraints,	     \
+		   in_constraints, clobber )				     \
+	do {								     \
+		segoff_t __routine = routine;				     \
+		__asm__ __volatile__ (					     \
+				      "pushl %" #num_out_constraints "\n\t"  \
+				      "call 1f\n\t"			     \
+				      "jmp 2f\n\t"			     \
+				      "\n1:\n\t"			     \
+				      "pushl installed_librm\n\t"	     \
+				      "addl $_real_call, 0(%%esp)\n\t"	     \
+				      "ret\n\t"				     \
+				      "\n2:\n\t"			     \
+				      "addl $4, %%esp\n\t"		     \
+				      : out_constraints			     \
+				      : in_constraints			     \
+				      : clobber				     \
+				      );				     \
+	} while ( 0 )
+
+/* REAL_EXEC: combine RM_FRAGMENT and REAL_CALL into one handy unit */
+#define PASSTHRU(...) __VA_ARGS__
+#define REAL_EXEC( name, asm_code_str, num_out_constraints, out_constraints, \
+		   in_constraints, clobber )				     \
+	do {								     \
+		segoff_t fragment;					     \
+									     \
+		REAL_FRAGMENT ( name, asm_code_str );			     \
+									     \
+		fragment.segment = inst_rm_stack.segment;		     \
+		fragment.offset =					     \
+			copy_to_rm_stack ( name, FRAGMENT_SIZE ( name ) );   \
+									     \
+		REAL_CALL ( fragment, num_out_constraints,		     \
+			    PASSTHRU ( out_constraints ),		     \
+			    PASSTHRU ( in_constraints ),		     \
+			    PASSTHRU ( clobber ) );			     \
+									     \
+		remove_from_rm_stack ( NULL, FRAGMENT_SIZE ( name ) );	     \
+	} while ( 0 )
+
+#endif /* ASSEMBLY */
+
+#endif /* LIBRM_H */