Towards a(nother) new real-mode infrastructure, in which we take

advantage of the fact that we have to have a permanently-resident block
in base memory.

src/arch/i386/transitions/librm_mgmt.c

@@ -9,44 +9,28 @@
 /* Build a null object under -DKEEP_IT_REAL */
 #else
 
-#include "stdint.h"
-#include "stddef.h"
-#include "string.h"
-#include "basemem.h"
-#include "relocate.h"
-#include <gpxe/init.h>
-#include "librm.h"
+#include <stdint.h>
+#include <librm.h>
 
 /*
  * This file provides functions for managing librm.
  *
  */
 
-/* Current location of librm in base memory */
-char *installed_librm = librm;
-
-/* Whether or not we have base memory currently allocated for librm.
- * Note that we *can* have a working librm present in unallocated base
- * memory; this is the situation at startup for all real-mode
- * prefixes.
- */
-static int allocated_librm = 0;
-
 /*
  * Allocate space on the real-mode stack and copy data there.
  *
  */
 uint16_t copy_to_rm_stack ( void *data, size_t size ) {
 #ifdef DEBUG_LIBRM
-	if ( inst_rm_stack.offset <= size ) {
+	if ( rm_sp <= size ) {
 		printf ( "librm: out of space in RM stack\n" );
 		lockup();
 	}
 #endif
-	inst_rm_stack.offset -= size;
-	copy_to_real ( inst_rm_stack.segment, inst_rm_stack.offset,
-		       data, size );
-	return inst_rm_stack.offset;
+	rm_sp -= size;
+	copy_to_real ( rm_ss, rm_sp, data, size );
+	return rm_sp;
 };
 
 /*
@@ -56,120 +40,9 @@ uint16_t copy_to_rm_stack ( void *data, size_t size ) {
  */
 void remove_from_rm_stack ( void *data, size_t size ) {
 	if ( data ) {
-		copy_from_real ( data,
-				 inst_rm_stack.segment, inst_rm_stack.offset,
-				 size );
+		copy_from_real ( data, rm_ss, rm_sp, size );
 	}
-	inst_rm_stack.offset += size;
+	rm_sp += size;
 };
 
-/*
- * Install librm to base memory
- *
- */
-static void install_librm ( char *addr ) {
-	librm_base = virt_to_phys ( addr );
-	memcpy ( addr, librm, librm_size );
-	installed_librm = addr;
-}
-
-/*
- * Uninstall librm from base memory.  This copies librm back to the
- * "master" copy, so that it can be reinstalled to a new location,
- * preserving the values for rm_ss and rm_sp from the old installed
- * copy.
- *
- * We deliberately leave the old copy intact and effectively installed
- * (apart from being in unallocated memory) so that we can use it for
- * any real-mode calls required when allocating memory for the new
- * copy, or for the real-mode exit path.
- */
-static void uninstall_librm ( void ) {
-
-	/* Copy installed librm back to master copy */
-	memcpy ( librm, installed_librm, librm_size );
-
-	/* Free but do not zero the base memory */
-	if ( allocated_librm ) {
-		free_base_memory ( installed_librm, librm_size );
-		allocated_librm = 0;
-	}
-}
-
-/*
- * If librm isn't installed (i.e. if we have librm, but weren't
- * entered via it), then install librm and a real-mode stack to a
- * fixed temporary location, just so that we can e.g. issue printf()
- *
- * [ If we were entered via librm, then the real_to_prot call will
- * have filled in librm_base. ]
- */
-static void librm_init ( void ) {
-	if ( ! librm_base ) {
-		install_librm ( phys_to_virt ( 0x7c00 ) );
-		inst_rm_stack.segment = 0x7c0;
-		inst_rm_stack.offset = 0x1000;
-	}
-}
-
-/*
- * librm_post_reloc gets called immediately after relocation.
- *
- */
-static void librm_post_reloc ( void ) {
-	/* Point installed_librm back at last known physical location.
-	 */
-	installed_librm = phys_to_virt ( librm_base );
-
-	/* Allocate base memory for librm and place a copy there */
-	if ( ! allocated_librm ) {
-		char *new_librm = alloc_base_memory ( librm_size );
-		uninstall_librm ();
-		install_librm ( new_librm );
-		allocated_librm = 1;
-	}
-}
-
-INIT_FN ( INIT_LIBRM, librm_init, NULL, uninstall_librm );
-POST_RELOC_FN ( POST_RELOC_LIBRM, librm_post_reloc );
-
-/*
- * Wrapper for initialise() when librm is being used.  We have to
- * install a copy of librm to allocated base memory and return the
- * pointer to this new librm's entry point via es:di.
- *
- */
-void initialise_via_librm ( struct i386_all_regs *ix86 ) {
-	/* Hand off to initialise() */
-	initialise ();
-
-	/* Point es:di to new librm's entry point.  Fortunately, di is
-	 * already set up by setup16, so all we need to do is point
-	 * es:0000 to the start of the new librm.
-	 */
-	ix86->segs.es = librm_base >> 4;
-}
-
-/*
- * Increment lock count of librm
- *
- */
-void lock_librm ( void ) {
-	inst_librm_ref_count++;
-}
-
-/*
- * Decrement lock count of librm
- *
- */
-void unlock_librm ( void ) {
-#ifdef DEBUG_LIBRM
-	if ( inst_librm_ref_count == 0 ) {
-		printf ( "librm: ref count gone negative\n" );
-		lockup();
-	}
-#endif
-	inst_librm_ref_count--;
-}
-
 #endif /* KEEP_IT_REAL */