Added post-relocation function table.

3 files changed, 40 insertions, 10 deletions

diff --git a/src/arch/i386/core/relocate.c b/src/arch/i386/core/relocate.c
index 98734535a..3a2702a1f 100644
--- a/src/arch/i386/core/relocate.c
+++ b/src/arch/i386/core/relocate.c
@@ -2,6 +2,7 @@
 #include "memsizes.h"
 #include "osdep.h"
 #include "etherboot.h"
+#include "init.h"
 #include "relocate.h"
 
 #ifndef KEEP_IT_REAL
@@ -38,6 +39,8 @@ extern char _max_align[];
 /* Linker symbols */
 extern char _text[];
 extern char _end[];
+extern struct post_reloc_fn post_reloc_fns[];
+extern struct post_reloc_fn post_reloc_fns_end[];
 
 #undef DBG
 #ifdef DEBUG_RELOCATE
@@ -46,9 +49,10 @@ extern char _end[];
 #define DBG(...)
 #endif
 
-void relocate ( void ) {
+static void relocate ( void ) {
 	unsigned long addr, eaddr, size;
 	unsigned i;
+	struct post_reloc_fn *post_reloc_fn;
 
 	/* Walk through the memory map and find the highest address
 	 * below 4GB that etherboot will fit into.  Ensure etherboot
@@ -186,12 +190,23 @@ void relocate ( void ) {
 
 		relocate_to ( addr );
 		/* Note that we cannot make real-mode calls
-		 * (e.g. printf) at this point, because the pointer
-		 * installed_librm uses a virtual address (in order
-		 * that it can have a valid initialiser) and so is
-		 * currently invalid.
+		 * (e.g. printf) at this point, because librm has just
+		 * been moved to high memory.
 		 */
+
+		/* Call any registered post-relocation functions.
+		 * librm has a post-relocation function to install a
+		 * new librm into base memory.
+		 */
+		for ( post_reloc_fn = post_reloc_fns;
+		      post_reloc_fn < post_reloc_fns_end ; post_reloc_fn++ ) {
+			if ( post_reloc_fn->post_reloc )
+				post_reloc_fn->post_reloc ();
+		}
+		
 	}
 }
 
+INIT_FN ( INIT_RELOCATE, relocate, NULL, NULL );
+
 #endif /* ! KEEP_IT_REAL */
diff --git a/src/arch/i386/include/relocate.h b/src/arch/i386/include/relocate.h
index 4aec54e48..31965d4fb 100644
--- a/src/arch/i386/include/relocate.h
+++ b/src/arch/i386/include/relocate.h
@@ -1,14 +1,24 @@
 #ifndef RELOCATE_H
 #define RELOCATE_H
 
-#ifdef KEEP_IT_REAL
-
 /* relocate() is conceptually impossible with KEEP_IT_REAL */
-#define relocate()
+#ifndef KEEP_IT_REAL
+
+/* An entry in the post-relocation function table */
+struct post_reloc_fn {
+	void ( *post_reloc ) ( void );
+};
 
-#else
+/* Use double digits to avoid problems with "10" < "9" on alphabetic sort */
+#define POST_RELOC_LIBRM	"00"
 
-extern void relocate ( void );
+/* Macro for creating a post-relocation function table entry */
+#define POST_RELOC_FN( post_reloc_order, post_reloc_func )		      \
+	static struct post_reloc_fn post_reloc_functions		      \
+	    __attribute__ (( used, __section__( ".post_reloc_fns."	      \
+						post_reloc_order ) )) = {     \
+		.post_reloc = post_reloc_func,				      \
+	};
 
 #endif
 
diff --git a/src/arch/i386/scripts/i386.lds b/src/arch/i386/scripts/i386.lds
index 4f9df5619..6888da364 100644
--- a/src/arch/i386/scripts/i386.lds
+++ b/src/arch/i386/scripts/i386.lds
@@ -140,6 +140,8 @@ SECTIONS {
 	__data = .;
 	*(.data)
 	*(.data.*)
+
+	/* Various tables */
 	pci_drivers = .;
 	*(.drivers.pci)
 	pci_drivers_end = .;
@@ -149,6 +151,9 @@ SECTIONS {
 	console_drivers = .;
 	*(.drivers.console)
 	console_drivers_end = .;
+	post_reloc_fns = .;
+	*(SORT(.post_reloc_fns.*))
+	post_reloc_fns_end = .;
 	init_fns = .;
 	*(SORT(.init_fns.*))
 	init_fns_end = .;