diff --git a/arch/powerpc/include/asm/btext.h b/arch/powerpc/include/asm/btext.h
index 906f46e31006..89fc382648bc 100644
--- a/arch/powerpc/include/asm/btext.h
+++ b/arch/powerpc/include/asm/btext.h
@@ -13,6 +13,7 @@ extern void btext_update_display(unsigned long phys, int width, int height,
 extern void btext_setup_display(int width, int height, int depth, int pitch,
 				unsigned long address);
 extern void btext_prepare_BAT(void);
+extern void btext_map(void);
 extern void btext_unmap(void);
 
 extern void btext_drawchar(char c);
diff --git a/arch/powerpc/kernel/btext.c b/arch/powerpc/kernel/btext.c
index ac8f52732fde..0428992fdb4b 100644
--- a/arch/powerpc/kernel/btext.c
+++ b/arch/powerpc/kernel/btext.c
@@ -25,11 +25,6 @@
 static void scrollscreen(void);
 #endif
 
-static void draw_byte(unsigned char c, long locX, long locY);
-static void draw_byte_32(unsigned char *bits, unsigned int *base, int rb);
-static void draw_byte_16(unsigned char *bits, unsigned int *base, int rb);
-static void draw_byte_8(unsigned char *bits, unsigned int *base, int rb);
-
 #define __force_data __attribute__((__section__(".data")))
 
 static int g_loc_X __force_data;
@@ -52,6 +47,26 @@ static unsigned char vga_font[cmapsz];
 int boot_text_mapped __force_data = 0;
 int force_printk_to_btext = 0;
 
+extern void rmci_on(void);
+extern void rmci_off(void);
+
+static inline void rmci_maybe_on(void)
+{
+#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
+	if (!(mfmsr() & MSR_DR))
+		rmci_on();
+#endif
+}
+
+static inline void rmci_maybe_off(void)
+{
+#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
+	if (!(mfmsr() & MSR_DR))
+		rmci_off();
+#endif
+}
+
+
 #ifdef CONFIG_PPC32
 /* Calc BAT values for mapping the display and store them
  * in disp_BAT.  Those values are then used from head.S to map
@@ -134,7 +149,7 @@ void __init btext_unmap(void)
  *    changes.
  */
 
-static void map_boot_text(void)
+void btext_map(void)
 {
 	unsigned long base, offset, size;
 	unsigned char *vbase;
@@ -209,7 +224,7 @@ int btext_initialize(struct device_node *np)
 	dispDeviceRect[2] = width;
 	dispDeviceRect[3] = height;
 
-	map_boot_text();
+	btext_map();
 
 	return 0;
 }
@@ -283,7 +298,7 @@ void btext_update_display(unsigned long phys, int width, int height,
 		iounmap(logicalDisplayBase);
 		boot_text_mapped = 0;
 	}
-	map_boot_text();
+	btext_map();
 	g_loc_X = 0;
 	g_loc_Y = 0;
 	g_max_loc_X = width / 8;
@@ -298,6 +313,7 @@ void btext_clearscreen(void)
 					(dispDeviceDepth >> 3)) >> 2;
 	int i,j;
 
+	rmci_maybe_on();
 	for (i=0; i<(dispDeviceRect[3] - dispDeviceRect[1]); i++)
 	{
 		unsigned int *ptr = base;
@@ -305,6 +321,7 @@ void btext_clearscreen(void)
 			*(ptr++) = 0;
 		base += (dispDeviceRowBytes >> 2);
 	}
+	rmci_maybe_off();
 }
 
 void btext_flushscreen(void)
@@ -355,6 +372,8 @@ static void scrollscreen(void)
 				   (dispDeviceDepth >> 3)) >> 2;
 	int i,j;
 
+	rmci_maybe_on();
+
 	for (i=0; i<(dispDeviceRect[3] - dispDeviceRect[1] - 16); i++)
 	{
 		unsigned int *src_ptr = src;
@@ -371,9 +390,116 @@ static void scrollscreen(void)
 			*(dst_ptr++) = 0;
 		dst += (dispDeviceRowBytes >> 2);
 	}
+
+	rmci_maybe_off();
 }
 #endif /* ndef NO_SCROLL */
 
+static unsigned int expand_bits_8[16] = {
+	0x00000000,
+	0x000000ff,
+	0x0000ff00,
+	0x0000ffff,
+	0x00ff0000,
+	0x00ff00ff,
+	0x00ffff00,
+	0x00ffffff,
+	0xff000000,
+	0xff0000ff,
+	0xff00ff00,
+	0xff00ffff,
+	0xffff0000,
+	0xffff00ff,
+	0xffffff00,
+	0xffffffff
+};
+
+static unsigned int expand_bits_16[4] = {
+	0x00000000,
+	0x0000ffff,
+	0xffff0000,
+	0xffffffff
+};
+
+
+static void draw_byte_32(unsigned char *font, unsigned int *base, int rb)
+{
+	int l, bits;
+	int fg = 0xFFFFFFFFUL;
+	int bg = 0x00000000UL;
+
+	for (l = 0; l < 16; ++l)
+	{
+		bits = *font++;
+		base[0] = (-(bits >> 7) & fg) ^ bg;
+		base[1] = (-((bits >> 6) & 1) & fg) ^ bg;
+		base[2] = (-((bits >> 5) & 1) & fg) ^ bg;
+		base[3] = (-((bits >> 4) & 1) & fg) ^ bg;
+		base[4] = (-((bits >> 3) & 1) & fg) ^ bg;
+		base[5] = (-((bits >> 2) & 1) & fg) ^ bg;
+		base[6] = (-((bits >> 1) & 1) & fg) ^ bg;
+		base[7] = (-(bits & 1) & fg) ^ bg;
+		base = (unsigned int *) ((char *)base + rb);
+	}
+}
+
+static inline void draw_byte_16(unsigned char *font, unsigned int *base, int rb)
+{
+	int l, bits;
+	int fg = 0xFFFFFFFFUL;
+	int bg = 0x00000000UL;
+	unsigned int *eb = (int *)expand_bits_16;
+
+	for (l = 0; l < 16; ++l)
+	{
+		bits = *font++;
+		base[0] = (eb[bits >> 6] & fg) ^ bg;
+		base[1] = (eb[(bits >> 4) & 3] & fg) ^ bg;
+		base[2] = (eb[(bits >> 2) & 3] & fg) ^ bg;
+		base[3] = (eb[bits & 3] & fg) ^ bg;
+		base = (unsigned int *) ((char *)base + rb);
+	}
+}
+
+static inline void draw_byte_8(unsigned char *font, unsigned int *base, int rb)
+{
+	int l, bits;
+	int fg = 0x0F0F0F0FUL;
+	int bg = 0x00000000UL;
+	unsigned int *eb = (int *)expand_bits_8;
+
+	for (l = 0; l < 16; ++l)
+	{
+		bits = *font++;
+		base[0] = (eb[bits >> 4] & fg) ^ bg;
+		base[1] = (eb[bits & 0xf] & fg) ^ bg;
+		base = (unsigned int *) ((char *)base + rb);
+	}
+}
+
+static noinline void draw_byte(unsigned char c, long locX, long locY)
+{
+	unsigned char *base	= calc_base(locX << 3, locY << 4);
+	unsigned char *font	= &vga_font[((unsigned int)c) * 16];
+	int rb			= dispDeviceRowBytes;
+
+	rmci_maybe_on();
+	switch(dispDeviceDepth) {
+	case 24:
+	case 32:
+		draw_byte_32(font, (unsigned int *)base, rb);
+		break;
+	case 15:
+	case 16:
+		draw_byte_16(font, (unsigned int *)base, rb);
+		break;
+	case 8:
+		draw_byte_8(font, (unsigned int *)base, rb);
+		break;
+	}
+	rmci_maybe_off();
+}
+
 void btext_drawchar(char c)
 {
 	int cline = 0;
@@ -465,107 +591,12 @@ void btext_drawhex(unsigned long v)
 	btext_drawchar(' ');
 }
 
-static void draw_byte(unsigned char c, long locX, long locY)
+void __init udbg_init_btext(void)
 {
-	unsigned char *base	= calc_base(locX << 3, locY << 4);
-	unsigned char *font	= &vga_font[((unsigned int)c) * 16];
-	int rb			= dispDeviceRowBytes;
-
-	switch(dispDeviceDepth) {
-	case 24:
-	case 32:
-		draw_byte_32(font, (unsigned int *)base, rb);
-		break;
-	case 15:
-	case 16:
-		draw_byte_16(font, (unsigned int *)base, rb);
-		break;
-	case 8:
-		draw_byte_8(font, (unsigned int *)base, rb);
-		break;
-	}
-}
-
-static unsigned int expand_bits_8[16] = {
-	0x00000000,
-	0x000000ff,
-	0x0000ff00,
-	0x0000ffff,
-	0x00ff0000,
-	0x00ff00ff,
-	0x00ffff00,
-	0x00ffffff,
-	0xff000000,
-	0xff0000ff,
-	0xff00ff00,
-	0xff00ffff,
-	0xffff0000,
-	0xffff00ff,
-	0xffffff00,
-	0xffffffff
-};
-
-static unsigned int expand_bits_16[4] = {
-	0x00000000,
-	0x0000ffff,
-	0xffff0000,
-	0xffffffff
-};
-
-
-static void draw_byte_32(unsigned char *font, unsigned int *base, int rb)
-{
-	int l, bits;
-	int fg = 0xFFFFFFFFUL;
-	int bg = 0x00000000UL;
-
-	for (l = 0; l < 16; ++l)
-	{
-		bits = *font++;
-		base[0] = (-(bits >> 7) & fg) ^ bg;
-		base[1] = (-((bits >> 6) & 1) & fg) ^ bg;
-		base[2] = (-((bits >> 5) & 1) & fg) ^ bg;
-		base[3] = (-((bits >> 4) & 1) & fg) ^ bg;
-		base[4] = (-((bits >> 3) & 1) & fg) ^ bg;
-		base[5] = (-((bits >> 2) & 1) & fg) ^ bg;
-		base[6] = (-((bits >> 1) & 1) & fg) ^ bg;
-		base[7] = (-(bits & 1) & fg) ^ bg;
-		base = (unsigned int *) ((char *)base + rb);
-	}
-}
-
-static void draw_byte_16(unsigned char *font, unsigned int *base, int rb)
-{
-	int l, bits;
-	int fg = 0xFFFFFFFFUL;
-	int bg = 0x00000000UL;
-	unsigned int *eb = (int *)expand_bits_16;
-
-	for (l = 0; l < 16; ++l)
-	{
-		bits = *font++;
-		base[0] = (eb[bits >> 6] & fg) ^ bg;
-		base[1] = (eb[(bits >> 4) & 3] & fg) ^ bg;
-		base[2] = (eb[(bits >> 2) & 3] & fg) ^ bg;
-		base[3] = (eb[bits & 3] & fg) ^ bg;
-		base = (unsigned int *) ((char *)base + rb);
-	}
-}
-
-static void draw_byte_8(unsigned char *font, unsigned int *base, int rb)
-{
-	int l, bits;
-	int fg = 0x0F0F0F0FUL;
-	int bg = 0x00000000UL;
-	unsigned int *eb = (int *)expand_bits_8;
-
-	for (l = 0; l < 16; ++l)
-	{
-		bits = *font++;
-		base[0] = (eb[bits >> 4] & fg) ^ bg;
-		base[1] = (eb[bits & 0xf] & fg) ^ bg;
-		base = (unsigned int *) ((char *)base + rb);
-	}
+	/* If btext is enabled, we might have a BAT setup for early display,
+	 * thus we do enable some very basic udbg output
+	 */
+	udbg_putc = btext_drawchar;
 }
 
 static unsigned char vga_font[cmapsz] = {
@@ -913,10 +944,3 @@ static unsigned char vga_font[cmapsz] = {
 0x00, 0x00, 0x00, 0x00,
 };
 
-void __init udbg_init_btext(void)
-{
-	/* If btext is enabled, we might have a BAT setup for early display,
-	 * thus we do enable some very basic udbg output
-	 */
-	udbg_putc = btext_drawchar;
-}
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index a781566d3993..0db7cb4060c1 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -249,6 +249,37 @@ _GLOBAL(__bswapdi2)
 	blr
 
 #if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)
+
+_GLOBAL(rmci_on)
+	sync
+	isync
+	li	r3,0x100
+	rldicl	r3,r3,32,0
+	mfspr	r5,SPRN_HID4
+	or	r5,r5,r3
+	sync
+	mtspr	SPRN_HID4,r5
+	isync
+	slbia
+	isync
+	sync
+	blr
+
+_GLOBAL(rmci_off)
+	sync
+	isync
+	li	r3,0x100
+	rldicl	r3,r3,32,0
+	mfspr	r5,SPRN_HID4
+	andc	r5,r5,r3
+	sync
+	mtspr	SPRN_HID4,r5
+	isync
+	slbia
+	isync
+	sync
+	blr
+
 /*
  * Do an IO access in real mode
  */
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 607902424e73..57df5cb1dcc4 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -2082,6 +2082,22 @@ static void __init prom_check_displays(void)
 					   clut[2]) != 0)
 				break;
 #endif /* CONFIG_LOGO_LINUX_CLUT224 */
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
+		if (prom_getprop(node, "linux,boot-display", NULL, 0) !=
+		    PROM_ERROR) {
+			u32 width, height, pitch, addr;
+
+			prom_printf("Setting btext !\n");
+			prom_getprop(node, "width", &width, 4);
+			prom_getprop(node, "height", &height, 4);
+			prom_getprop(node, "linebytes", &pitch, 4);
+			prom_getprop(node, "address", &addr, 4);
+			prom_printf("W=%d H=%d LB=%d addr=0x%x\n",
+				    width, height, pitch, addr);
+			btext_setup_display(width, height, 8, pitch, addr);
+		}
+#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
 	}
 }
 
diff --git a/arch/powerpc/kernel/prom_init_check.sh b/arch/powerpc/kernel/prom_init_check.sh
index 3765da6be4f2..b0c263da219a 100644
--- a/arch/powerpc/kernel/prom_init_check.sh
+++ b/arch/powerpc/kernel/prom_init_check.sh
@@ -22,7 +22,8 @@ __secondary_hold_acknowledge __secondary_hold_spinloop __start
 strcmp strcpy strlcpy strlen strncmp strstr logo_linux_clut224
 reloc_got2 kernstart_addr memstart_addr linux_banner _stext
 opal_query_takeover opal_do_takeover opal_enter_rtas opal_secondary_entry
-boot_command_line __prom_init_toc_start __prom_init_toc_end"
+boot_command_line __prom_init_toc_start __prom_init_toc_end
+btext_setup_display"
 
 NM="$1"
 OBJ="$2"
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 79ba9b77fe72..0c0450dd4d31 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -10,7 +10,7 @@
  *      2 of the License, or (at your option) any later version.
  */
 
-#undef DEBUG
+#define DEBUG
 
 #include <linux/export.h>
 #include <linux/string.h>
@@ -240,6 +240,18 @@ void __init early_setup(unsigned long dt_ptr)
 	reserve_hugetlb_gpages();
 
 	DBG(" <- early_setup()\n");
+
+#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
+	/*
+	 * This needs to be done *last* (after the above DBG() even)
+	 *
+	 * Right after we return from this function, we turn on the MMU
+	 * which means the real-mode access trick that btext does will
+	 * no longer work, it needs to switch to using a real MMU
+	 * mapping. This call will ensure that it does
+	 */
+	btext_map();
+#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */
 }
 
 #ifdef CONFIG_SMP