x86: Parametize values used in linker script

arch/i386/config.mk

@@ -32,6 +32,7 @@ PLATFORM_CPPFLAGS += $(call cc-option, -fno-toplevel-reorder,  $(call cc-option,
 PLATFORM_CPPFLAGS += $(call cc-option, -fno-stack-protector)
 PLATFORM_CPPFLAGS += $(call cc-option, -mpreferred-stack-boundary=2)
 PLATFORM_CPPFLAGS += -fno-dwarf2-cfi-asm
+PLATFORM_CPPFLAGS += -DREALMODE_BASE=0x7c0
 
 PLATFORM_RELFLAGS += -ffunction-sections -fvisibility=hidden
 

arch/i386/cpu/config.mk

@@ -24,3 +24,9 @@
 CROSS_COMPILE ?= i386-linux-
 
 PLATFORM_CPPFLAGS += -DCONFIG_I386 -D__I386__ -march=i386 -Werror
+
+# DO NOT MODIFY THE FOLLOWING UNLESS YOU REALLY KNOW WHAT YOU ARE DOING!
+LDPPFLAGS += -DRESET_SEG_START=0xffff0000
+LDPPFLAGS += -DRESET_SEG_SIZE=0x10000
+LDPPFLAGS += -DRESET_VEC_LOC=0xfff0
+LDPPFLAGS += -DSTART_16=0xf800

arch/i386/cpu/u-boot.lds

@@ -73,7 +73,7 @@ SECTIONS
 	/DISCARD/ : { *(.gnu*) }
 
 	/* 16bit realmode trampoline code */
-	.realmode 0x7c0 : AT ( LOADADDR(.rel.dyn) + SIZEOF(.rel.dyn) ) { KEEP(*(.realmode)) }
+	.realmode REALMODE_BASE : AT ( LOADADDR(.rel.dyn) + SIZEOF(.rel.dyn) ) { KEEP(*(.realmode)) }
 
 	__realmode_start = LOADADDR(.realmode);
 	__realmode_size = SIZEOF(.realmode);
@@ -84,21 +84,13 @@ SECTIONS
 	__bios_start = LOADADDR(.bios);
 	__bios_size = SIZEOF(.bios);
 
-	/* The load addresses below assumes that the flash
-	 * will be mapped so that 0x387f0000 == 0xffff0000
-	 * at reset time
-	 *
-	 * The fe00 and ff00 offsets of the start32 and start16
-	 * segments are arbitrary, the just have to be mapped
-	 * at reset and the code have to fit.
-	 * The fff0 offset of resetvec is important, however.
+	/*
+	 * The following expressions place the 16-bit Real-Mode code and
+	 * Reset Vector at the end of the Flash ROM
 	 */
-	. = 0xfffffe00;
-	.start32 : AT (CONFIG_SYS_TEXT_BASE + 0x3fe00) { KEEP(*(.start32)); }
+	. = START_16;
+	.start16 : AT (CONFIG_SYS_TEXT_BASE + (FLASH_SIZE - RESET_SEG_SIZE + START_16)) { KEEP(*(.start16)); }
 
-	. = 0xf800;
-	.start16 : AT (CONFIG_SYS_TEXT_BASE + 0x3f800) { KEEP(*(.start16)); }
-
-	. = 0xfff0;
-	.resetvec : AT (CONFIG_SYS_TEXT_BASE + 0x3fff0) { KEEP(*(.resetvec)); }
+	. = RESET_VEC_LOC;
+	.resetvec : AT (CONFIG_SYS_TEXT_BASE + (FLASH_SIZE - RESET_SEG_SIZE + RESET_VEC_LOC)) { KEEP(*(.resetvec)); }
 }

arch/i386/lib/realmode.c

@@ -27,7 +27,6 @@
 #include <asm/realmode.h>
 
 
-#define REALMODE_BASE    ((char*)0x7c0)
 #define REALMODE_MAILBOX ((char*)0xe00)
 
 
@@ -41,13 +40,14 @@ int realmode_setup(void)
 	ulong realmode_size = (ulong)&__realmode_size;
 
 	/* copy the realmode switch code */
-	if (realmode_size > (REALMODE_MAILBOX-REALMODE_BASE)) {
+	if (realmode_size > (REALMODE_MAILBOX - (char *)REALMODE_BASE)) {
 		printf("realmode switch too large (%ld bytes, max is %d)\n",
-		       realmode_size, (REALMODE_MAILBOX-REALMODE_BASE));
+		       realmode_size,
+		       (REALMODE_MAILBOX - (char *)REALMODE_BASE));
 		return -1;
 	}
 
-	memcpy(REALMODE_BASE, (void*)realmode_start, realmode_size);
+	memcpy((char *)REALMODE_BASE, (void *)realmode_start, realmode_size);
 	asm("wbinvd\n");
 
 	return 0;

board/eNET/config.mk

@@ -21,3 +21,4 @@
 # MA 02111-1307 USA
 #
 
+LDPPFLAGS += -DFLASH_SIZE=0x40000