Merged mcb30-realmode-redesign back to HEAD

1 files changed, 184 insertions, 0 deletions

diff --git a/src/arch/i386/include/libkir.h b/src/arch/i386/include/libkir.h
new file mode 100644
index 000000000..5bac42d88
--- /dev/null
+++ b/src/arch/i386/include/libkir.h
@@ -0,0 +1,184 @@
+#ifndef LIBKIR_H
+#define LIBKIR_H
+
+#include "realmode.h"
+
+#ifndef ASSEMBLY
+
+/*
+ * Full API documentation for these functions is in realmode.h.
+ *
+ */
+
+/* Copy to/from base memory */
+
+static inline void copy_to_real_libkir ( uint16_t dest_seg, uint16_t dest_off,
+					 void *src, size_t n ) {
+	__asm__ ( "movw %4, %%es\n\t"
+		  "cld\n\t"
+		  "rep movsb\n\t"
+		  "pushw %%ds\n\t" /* restore %es */
+		  "popw %%es\n\t"
+		  : "=S" ( src ), "=D" ( dest_off ), "=c" ( n ) /* clobbered */
+		  : "S" ( src ), "r" ( dest_seg ), "D" ( dest_off ), "c" ( n )
+		  : "memory"
+		  );
+}
+
+static inline void copy_from_real_libkir ( void *dest,
+					   uint16_t src_seg, uint16_t src_off,
+					   size_t n ) {
+	__asm__ ( "movw %%ax, %%ds\n\t"
+		  "cld\n\t"
+		  "rep movsb\n\t"
+		  "pushw %%es\n\t" /* restore %ds */
+		  "popw %%ds\n\t"
+		  : "=S" ( src_off ), "=D" ( dest ), "=c" ( n ) /* clobbered */
+		  : "a" ( src_seg ), "S" ( src_off ), "D" ( dest ), "c" ( n )
+		  : "memory"
+		  );
+}
+#define copy_to_real copy_to_real_libkir
+#define copy_from_real copy_from_real_libkir
+
+/*
+ * Transfer individual values to/from base memory.  There may well be
+ * a neater way to do this.  We have two versions: one for constant
+ * offsets (where the mov instruction must be of the form "mov
+ * %es:123, %xx") and one for non-constant offsets (where the mov
+ * instruction must be of the form "mov %es:(%xx), %yx".  If it's
+ * possible to incorporate both forms into one __asm__ instruction, I
+ * don't know how to do it.
+ *
+ * Ideally, the mov instruction should be "mov%z0"; the "%z0" is meant
+ * to expand to either "b", "w" or "l" depending on the size of
+ * operand 0.  This would remove the (minor) ambiguity in the mov
+ * instruction.  However, gcc on at least my system barfs with an
+ * "internal compiler error" when confronted with %z0.
+ *
+ */
+
+#define put_real_kir_const_off( var, seg, off )		  		     \
+	__asm__ ( "movw %w1, %%es\n\t"					     \
+		  "mov %0, %%es:%c2\n\t"				     \
+		  "pushw %%ds\n\t" /* restore %es */			     \
+		  "popw %%es\n\t"					     \
+		  :							     \
+		  : "r,r" ( var ), "rm,rm" ( seg ), "i,!r" ( off )	     \
+		  )
+
+#define put_real_kir_nonconst_off( var, seg, off )	  		     \
+	__asm__ ( "movw %w1, %%es\n\t"					     \
+		  "mov %0, %%es:(%2)\n\t"				     \
+		  "pushw %%ds\n\t" /* restore %es */			     \
+		  "popw %%es\n\t"					     \
+		  :							     \
+		  : "r" ( var ), "rm" ( seg ), "r" ( off )		     \
+		  )
+
+#define put_real_kir( var, seg, off )					     \
+	do {								     \
+	  if ( __builtin_constant_p ( off ) )				     \
+		  put_real_kir_const_off ( var, seg, off );		     \
+	  else								     \
+		  put_real_kir_nonconst_off ( var, seg, off );		     \
+	} while ( 0 )
+
+#define get_real_kir_const_off( var, seg, off )		  		     \
+	__asm__ ( "movw %w1, %%es\n\t"					     \
+		  "mov %%es:%c2, %0\n\t"				     \
+		  "pushw %%ds\n\t" /* restore %es */			     \
+		  "popw %%es\n\t"					     \
+		  : "=r,r" ( var )					     \
+		  : "rm,rm" ( seg ), "i,!r" ( off )			     \
+		  )
+
+#define get_real_kir_nonconst_off( var, seg, off )			     \
+	__asm__ ( "movw %w1, %%es\n\t"					     \
+		  "mov %%es:(%2), %0\n\t"				     \
+		  "pushw %%ds\n\t" /* restore %es */			     \
+		  "popw %%es\n\t"					     \
+		  : "=r" ( var )					     \
+		  : "rm" ( seg ), "r" ( off )				     \
+		  )
+
+#define get_real_kir( var, seg, off )					     \
+	do {								     \
+	  if ( __builtin_constant_p ( off ) )				     \
+		  get_real_kir_const_off ( var, seg, off );		     \
+	  else								     \
+		  get_real_kir_nonconst_off ( var, seg, off );		     \
+	} while ( 0 )
+
+#define put_real put_real_kir
+#define get_real get_real_kir
+
+/* Place/remove parameter on real-mode stack in a way that's
+ * compatible with libkir
+ */
+#define BASEMEM_PARAMETER_INIT_LIBKIR( param ) \
+	( ( uint16_t ) ( ( uint32_t ) & ( param ) ) )
+#define BASEMEM_PARAMETER_DONE_LIBKIR( param )
+#define BASEMEM_PARAMETER_INIT BASEMEM_PARAMETER_INIT_LIBKIR
+#define BASEMEM_PARAMETER_DONE BASEMEM_PARAMETER_DONE_LIBKIR
+
+/* REAL_CALL: call an external real-mode routine */
+#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"		     \
+			".code16\n\t"					     \
+			"pushw %%gs\n\t"	/* preserve segs */	     \
+			"pushw %%fs\n\t"				     \
+			"pushw %%es\n\t"				     \
+			"pushw %%ds\n\t"				     \
+			"pushw %%cs\n\t"	/* lcall to routine */	     \
+			"call 1f\n\t"					     \
+			"jmp 2f\n\t"					     \
+			"\n1:\n\t"					     \
+			"addr32 pushl 12(%%esp)\n\t"			     \
+			"lret\n\t"					     \
+			"\n2:\n\t"					     \
+			"popw %%ds\n\t"		/* restore segs */	     \
+			"popw %%es\n\t"					     \
+			"popw %%fs\n\t"					     \
+			"popw %%gs\n\t"					     \
+			"addw $4, %%sp\n\t"				     \
+			".code16gcc\n\t"				     \
+			: out_constraints : in_constraints : clobber  	     \
+		);							     \
+	} while ( 0 )
+
+/* REAL_EXEC: execute some inline assembly code in a way that matches
+ * the interface of librm
+ */
+
+#define IN_CONSTRAINTS_NO_ROUTINE( routine, ... ) __VA_ARGS__
+#define REAL_EXEC( name, asm_code_str, num_out_constraints, out_constraints, \
+		   in_constraints, clobber )				     \
+	__asm__ __volatile__ (						     \
+		".code16\n\t"						     \
+		"pushw %%gs\n\t"					     \
+		"pushw %%fs\n\t"					     \
+		"pushw %%es\n\t"					     \
+		"pushw %%ds\n\t"					     \
+		"\n" #name ":\n\t"					     \
+		asm_code_str						     \
+		"popw %%ds\n\t"						     \
+		"popw %%es\n\t"						     \
+		"popw %%fs\n\t"						     \
+		"popw %%gs\n\t"						     \
+		".code16gcc\n\t"					     \
+		: out_constraints					     \
+		: IN_CONSTRAINTS_NO_ROUTINE ( in_constraints )		     \
+		: clobber				   		     \
+		);
+
+#endif /* ASSEMBLY */
+
+#endif /* LIBKIR_H */