[bios] Describe umalloc() heap as an in-use memory area

Use the concept of an in-use memory region defined as part of the
system memory map API to describe the umalloc() heap.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/arch/x86/include/basemem.h

@@ -27,9 +27,4 @@ static inline unsigned int get_fbms ( void ) {
 
 extern void set_fbms ( unsigned int new_fbms );
 
-/* Actually in hidemem.c, but putting it here avoids polluting the
- * architecture-independent include/hidemem.h.
- */
-extern void hide_basemem ( void );
-
 #endif /* _BASEMEM_H */

src/arch/x86/include/ipxe/int15.h

@@ -16,5 +16,6 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #endif
 
 extern void int15_intercept ( int intercept );
+extern void hide_basemem ( void );
 
 #endif /* _IPXE_INT15_H */

src/arch/x86/interface/pcbios/basemem.c

@@ -27,7 +27,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <realmode.h>
 #include <bios.h>
 #include <basemem.h>
-#include <ipxe/hidemem.h>
+#include <ipxe/memmap.h>
 
 /** @file
  *

src/arch/x86/interface/pcbios/hidemem.c

@@ -31,7 +31,6 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <ipxe/init.h>
 #include <ipxe/io.h>
 #include <ipxe/memmap.h>
-#include <ipxe/hidemem.h>
 
 /** Set to true if you want to test a fake E820 map */
 #define FAKE_E820 0
@@ -118,15 +117,6 @@ void hide_basemem ( void ) {
 	hidemem_base.start = ( get_fbms() * 1024 );
 }
 
-/**
- * Hide umalloc() region
- *
- */
-void hide_umalloc ( physaddr_t start, physaddr_t end ) {
-	assert ( end <= virt_to_phys ( _textdata ) );
-	hide_region ( &hidemem_umalloc, start, end );
-}
-
 /**
  * Hide .text and .data
  *
@@ -136,6 +126,26 @@ void hide_textdata ( void ) {
 		      virt_to_phys ( _etextdata ) );
 }
 
+/**
+ * Synchronise in-use regions with the externally visible system memory map
+ *
+ */
+static void int15_sync ( void ) {
+	physaddr_t start;
+	size_t size;
+
+	/* Besides our fixed base memory and textdata regions, we
+	 * support hiding only a single in-use memory region (the
+	 * umalloc region), which must be placed before the hidden
+	 * textdata region (even if zero-length).
+	 */
+	start = umalloc_used.start;
+	size = umalloc_used.size;
+	if ( ! size )
+		start = virt_to_phys ( _textdata );
+	hide_region ( &hidemem_umalloc, start, ( start + size ) );
+}
+
 /**
  * Set INT 15 interception flag
  *
@@ -172,8 +182,8 @@ static void hide_etherboot ( void ) {
 
 	/* Initialise the hidden regions */
 	hide_basemem();
-	hide_umalloc ( virt_to_phys ( _textdata ), virt_to_phys ( _textdata ) );
 	hide_textdata();
+	int15_sync();
 
 	/* Some really moronic BIOSes bring up the PXE stack via the
 	 * UNDI loader entry point and then don't bother to unload it
@@ -250,3 +260,5 @@ struct startup_fn hide_etherboot_startup_fn __startup_fn ( STARTUP_EARLY ) = {
 	.startup = hide_etherboot,
 	.shutdown = unhide_etherboot,
 };
+
+PROVIDE_MEMMAP ( int15, memmap_sync, int15_sync );

src/arch/x86/interface/pcbios/memtop_umalloc.c

@@ -34,9 +34,9 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #include <string.h>
 #include <errno.h>
 #include <ipxe/uaccess.h>
-#include <ipxe/hidemem.h>
 #include <ipxe/io.h>
 #include <ipxe/memblock.h>
+#include <ipxe/memmap.h>
 #include <ipxe/umalloc.h>
 
 /** Maximum usable address for external allocated memory */
@@ -62,6 +62,22 @@ static void *bottom = NULL;
 /** Remaining space on heap */
 static size_t heap_size;
 
+/** In-use memory region */
+struct used_region umalloc_used __used_region = {
+	.name = "umalloc",
+};
+
+/**
+ * Hide umalloc() region
+ *
+ * @v start		Start of region
+ * @v end		End of region
+ */
+static void hide_umalloc ( physaddr_t start, physaddr_t end ) {
+
+	memmap_use ( &umalloc_used, start, ( end - start ) );
+}
+
 /**
  * Find largest usable memory region
  *

src/include/ipxe/hidemem.h

@@ -1,17 +0,0 @@
-#ifndef _IPXE_HIDEMEM_H
-#define _IPXE_HIDEMEM_H
-
-/**
- * @file
- *
- * Hidden memory regions
- *
- */
-
-FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
-
-#include <stdint.h>
-
-extern void hide_umalloc ( physaddr_t start, physaddr_t end );
-
-#endif /* _IPXE_HIDEMEM_H */

src/include/ipxe/memmap.h

@@ -228,6 +228,8 @@ static inline void memmap_dump_all ( int hide ) {
 		memmap_dump ( &region );
 }
 
+extern struct used_region umalloc_used __used_region;
+
 extern void memmap_update ( struct memmap_region *region, uint64_t start,
 			    uint64_t size, unsigned int flags,
 			    const char *name );