--- /dev/null
+#ifndef LIBKIR_H
+#define LIBKIR_H
+
+#include "realmode.h"
+
+#ifndef ASSEMBLY
+
+/*
+ * Full API documentation for these functions is in realmode.h.
+ *
+ */
+
+/* Access to variables in .data16 and .text16 in a way compatible with librm */
+#define __data16( variable ) variable
+#define __data16_array( variable, array ) variable array
+#define __bss16( variable ) variable
+#define __bss16_array( variable, array ) variable array
+#define __text16( variable ) variable
+#define __text16_array( variable,array ) variable array
+#define __use_data16( variable ) variable
+#define __use_text16( variable ) variable
+#define __from_data16( pointer ) pointer
+#define __from_text16( pointer ) pointer
+
+/* Real-mode data and code segments */
+static inline __attribute__ (( always_inline )) unsigned int _rm_cs ( void ) {
+ uint16_t cs;
+ __asm__ __volatile__ ( "movw %%cs, %w0" : "=r" ( cs ) );
+ return cs;
+}
+
+static inline __attribute__ (( always_inline )) unsigned int _rm_ds ( void ) {
+ uint16_t ds;
+ __asm__ __volatile__ ( "movw %%ds, %w0" : "=r" ( ds ) );
+ return ds;
+}
+
+#define rm_cs ( _rm_cs() )
+#define rm_ds ( _rm_ds() )
+
+/* Copy to/from base memory */
+
+static inline void copy_to_real_libkir ( unsigned int dest_seg,
+ unsigned int dest_off,
+ const void *src, size_t n ) {
+ unsigned int discard_D, discard_S, discard_c;
+
+ __asm__ __volatile__ ( "pushw %%es\n\t"
+ "movw %3, %%es\n\t"
+ "rep movsb\n\t"
+ "popw %%es\n\t"
+ : "=D" ( discard_D ), "=S" ( discard_S ),
+ "=c" ( discard_c )
+ : "r" ( dest_seg ), "D" ( dest_off ),
+ "S" ( src ),
+ "c" ( n )
+ : "memory" );
+}
+
+static inline void copy_from_real_libkir ( void *dest,
+ unsigned int src_seg,
+ unsigned int src_off,
+ size_t n ) {
+ unsigned int discard_D, discard_S, discard_c;
+
+ __asm__ __volatile__ ( "pushw %%ds\n\t"
+ "movw %4, %%ds\n\t"
+ "rep movsb\n\t"
+ "popw %%ds\n\t"
+ : "=D" ( discard_D ), "=S" ( discard_S ),
+ "=c" ( discard_c )
+ : "D" ( dest ),
+ "r" ( src_seg ), "S" ( src_off ),
+ "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
+
+/**
+ * A pointer to a user buffer
+ *
+ * This is actually a struct segoff, but encoded as a uint32_t to
+ * ensure that gcc passes it around efficiently.
+ */
+typedef uint32_t userptr_t;
+
+/**
+ * Copy data to user buffer
+ *
+ * @v buffer User buffer
+ * @v offset Offset within user buffer
+ * @v src Source
+ * @v len Length
+ */
+static inline __attribute__ (( always_inline )) void
+copy_to_user ( userptr_t buffer, off_t offset, const void *src, size_t len ) {
+ copy_to_real ( ( buffer >> 16 ), ( ( buffer & 0xffff ) + offset ),
+ src, len );
+}
+
+/**
+ * Copy data from user buffer
+ *
+ * @v dest Destination
+ * @v buffer User buffer
+ * @v offset Offset within user buffer
+ * @v len Length
+ */
+static inline __attribute__ (( always_inline )) void
+copy_from_user ( void *dest, userptr_t buffer, off_t offset, size_t len ) {
+ copy_from_real ( dest, ( buffer >> 16 ),
+ ( ( buffer & 0xffff ) + offset ), len );
+}
+
+/**
+ * Convert segment:offset address to user buffer
+ *
+ * @v segment Real-mode segment
+ * @v offset Real-mode offset
+ * @ret buffer User buffer
+ */
+static inline __attribute__ (( always_inline )) userptr_t
+real_to_user ( unsigned int segment, unsigned int offset ) {
+ return ( ( segment << 16 ) | offset );
+}
+
+/**
+ * Convert virtual address to user buffer
+ *
+ * @v virtual Virtual address
+ * @ret buffer User buffer
+ *
+ * This constructs a user buffer from an ordinary pointer. Use it
+ * when you need to pass a pointer to an internal buffer to a function
+ * that expects a @c userptr_t.
+ */
+static inline __attribute__ (( always_inline )) userptr_t
+virt_to_user ( void * virtual ) {
+ return real_to_user ( rm_ds, ( intptr_t ) virtual );
+}
+
+/* TEXT16_CODE: declare a fragment of code that resides in .text16 */
+#define TEXT16_CODE( asm_code_str ) \
+ ".section \".text16\", \"ax\", @progbits\n\t" \
+ ".code16\n\t" \
+ ".arch i386\n\t" \
+ asm_code_str "\n\t" \
+ ".code16gcc\n\t" \
+ ".previous\n\t"
+
+/* REAL_CODE: declare a fragment of code that executes in real mode */
+#define REAL_CODE( asm_code_str ) \
+ ".code16\n\t" \
+ asm_code_str "\n\t" \
+ ".code16gcc\n\t"
+
+#endif /* ASSEMBLY */
+
+#endif /* LIBKIR_H */
Code Review / kvmfornfv.git / blobdiff