ARM: 6886/1: mmc, Add zboot from eSD support for SuperH Mobile ARM

This allows a ROM-able zImage to be written to eSD and for SuperH Mobile
ARM to boot directly from the SDHI hardware block.

This is achieved by the MaskROM loading the first portion of the image into
MERAM and then jumping to it.  This portion contains loader code which
copies the entire image to SDRAM and jumps to it. From there the zImage
boot code proceeds as normal, uncompressing the image into its final
location and then jumping to it.

Cc: Paul Mundt <lethal@linux-sh.org>
Acked-by: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt

+ROM-able zImage boot from eSD
+-----------------------------
+
+An ROM-able zImage compiled with ZBOOT_ROM_SDHI may be written to eSD and
+SuperH Mobile ARM will to boot directly from the SDHI hardware block.
+
+This is achieved by the mask ROM loading the first portion of the image into
+MERAM and then jumping to it. This portion contains loader code which
+copies the entire image to SDRAM and jumps to it. From there the zImage
+boot code proceeds as normal, uncompressing the image into its final
+location and then jumping to it.
+
+This code has been tested on an mackerel board using the developer 1A eSD
+boot mode which is configured using the following jumper settings.
+
+   8 7 6 5 4 3 2 1
+   x|x|x|x| |x|x|
+S4 -+-+-+-+-+-+-+-
+    | | | |x| | |x on
+
+The eSD card needs to be present in SDHI slot 1 (CN7).
+As such S1 and S33 also need to be configured as per
+the notes in arch/arm/mach-shmobile/board-mackerel.c.
+
+A partial zImage must be written to physical partition #1 (boot)
+of the eSD at sector 0 in vrl4 format. A utility vrl4 is supplied to
+accomplish this.
+
+e.g.
+	vrl4 < zImage | dd of=/dev/sdX bs=512 count=17
+
+A full copy of _the same_ zImage should be written to physical partition #1
+(boot) of the eSD at sector 0. This should _not_ be in vrl4 format.
+
+	vrl4 < zImage | dd of=/dev/sdX bs=512
+
+Note: The commands above assume that the physical partition has been
+switched. No such facility currently exists in the Linux Kernel.
+
+Physical partitions are described in the eSD specification.  At the time of
+writing they are not the same as partitions that are typically configured
+using fdisk and visible through /proc/partitions

arch/arm/Kconfig

@@ -1718,17 +1718,34 @@ config ZBOOT_ROM
 	  Say Y here if you intend to execute your compressed kernel image
 	  (zImage) directly from ROM or flash.  If unsure, say N.
 
+choice
+	prompt "Include SD/MMC loader in zImage (EXPERIMENTAL)"
+	depends on ZBOOT_ROM && ARCH_SH7372 && EXPERIMENTAL
+	default ZBOOT_ROM_NONE
+	help
+	  Include experimental SD/MMC loading code in the ROM-able zImage.
+	  With this enabled it is possible to write the the ROM-able zImage
+	  kernel image to an MMC or SD card and boot the kernel straight
+	  from the reset vector. At reset the processor Mask ROM will load
+	  the first part of the the ROM-able zImage which in turn loads the
+	  rest the kernel image to RAM.
+
+config ZBOOT_ROM_NONE
+	bool "No SD/MMC loader in zImage (EXPERIMENTAL)"
+	help
+	  Do not load image from SD or MMC
+
 config ZBOOT_ROM_MMCIF
 	bool "Include MMCIF loader in zImage (EXPERIMENTAL)"
-	depends on ZBOOT_ROM && ARCH_SH7372 && EXPERIMENTAL
 	help
-	  Say Y here to include experimental MMCIF loading code in the
-	  ROM-able zImage. With this enabled it is possible to write the
-	  the ROM-able zImage kernel image to an MMC card and boot the
-	  kernel straight from the reset vector. At reset the processor
-	  Mask ROM will load the first part of the the ROM-able zImage
-	  which in turn loads the rest the kernel image to RAM using the
-	  MMCIF hardware block.
+	  Load image from MMCIF hardware block.
+
+config ZBOOT_ROM_SH_MOBILE_SDHI
+	bool "Include SuperH Mobile SDHI loader in zImage (EXPERIMENTAL)"
+	help
+	  Load image from SDHI hardware block
+
+endchoice
 
 config CMDLINE
 	string "Default kernel command string"

arch/arm/boot/compressed/Makefile

@@ -6,13 +6,19 @@
 
 OBJS		=
 
-# Ensure that mmcif loader code appears early in the image
+# Ensure that MMCIF loader code appears early in the image
 # to minimise that number of bocks that have to be read in
 # order to load it.
 ifeq ($(CONFIG_ZBOOT_ROM_MMCIF),y)
-ifeq ($(CONFIG_ARCH_SH7372),y)
 OBJS		+= mmcif-sh7372.o
 endif
+
+# Ensure that SDHI loader code appears early in the image
+# to minimise that number of bocks that have to be read in
+# order to load it.
+ifeq ($(CONFIG_ZBOOT_ROM_SH_MOBILE_SDHI),y)
+OBJS		+= sdhi-shmobile.o
+OBJS		+= sdhi-sh7372.o
 endif
 
 AFLAGS_head.o += -DTEXT_OFFSET=$(TEXT_OFFSET)

arch/arm/boot/compressed/head-shmobile.S

@@ -25,14 +25,14 @@
 	/* load board-specific initialization code */
 #include <mach/zboot.h>
 
-#ifdef CONFIG_ZBOOT_ROM_MMCIF
-	/* Load image from MMC */
-	adr	sp, __tmp_stack + 128
+#if defined(CONFIG_ZBOOT_ROM_MMCIF) || defined(CONFIG_ZBOOT_ROM_SH_MOBILE_SDHI)
+	/* Load image from MMC/SD */
+	adr	sp, __tmp_stack + 256
 	ldr	r0, __image_start
 	ldr	r1, __image_end
 	subs	r1, r1, r0
 	ldr	r0, __load_base
-	bl	mmcif_loader
+	bl	mmc_loader
 
 	/* Jump to loaded code */
 	ldr	r0, __loaded
@@ -51,9 +51,9 @@ __loaded:
 	.long	__continue
 	.align
 __tmp_stack:
-	.space	128
+	.space	256
 __continue:
-#endif /* CONFIG_ZBOOT_ROM_MMCIF */
+#endif /* CONFIG_ZBOOT_ROM_MMC || CONFIG_ZBOOT_ROM_SH_MOBILE_SDHI */
 
 	b	1f
 __atags:@ tag #1

arch/arm/boot/compressed/mmcif-sh7372.c

@@ -40,7 +40,7 @@
  * to an MMC card
  * # dd if=vrl4.out of=/dev/sdx bs=512 seek=1
  */
-asmlinkage void mmcif_loader(unsigned char *buf, unsigned long len)
+asmlinkage void mmc_loader(unsigned char *buf, unsigned long len)
 {
 	mmc_init_progress();
 	mmc_update_progress(MMC_PROGRESS_ENTER);

arch/arm/boot/compressed/sdhi-sh7372.c

+/*
+ * SuperH Mobile SDHI
+ *
+ * Copyright (C) 2010 Magnus Damm
+ * Copyright (C) 2010 Kuninori Morimoto
+ * Copyright (C) 2010 Simon Horman
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Parts inspired by u-boot
+ */
+
+#include <linux/io.h>
+#include <mach/mmc.h>
+#include <linux/mmc/boot.h>
+#include <linux/mmc/tmio.h>
+
+#include "sdhi-shmobile.h"
+
+#define PORT179CR       0xe60520b3
+#define PORT180CR       0xe60520b4
+#define PORT181CR       0xe60520b5
+#define PORT182CR       0xe60520b6
+#define PORT183CR       0xe60520b7
+#define PORT184CR       0xe60520b8
+
+#define SMSTPCR3        0xe615013c
+
+#define CR_INPUT_ENABLE 0x10
+#define CR_FUNCTION1    0x01
+
+#define SDHI1_BASE	(void __iomem *)0xe6860000
+#define SDHI_BASE	SDHI1_BASE
+
+/*  SuperH Mobile SDHI loader
+ *
+ * loads the zImage from an SD card starting from block 0
+ * on physical partition 1
+ *
+ * The image must be start with a vrl4 header and
+ * the zImage must start at offset 512 of the image. That is,
+ * at block 1 (=byte 512) of physical partition 1
+ *
+ * Use the following line to write the vrl4 formated zImage
+ * to an SD card
+ * # dd if=vrl4.out of=/dev/sdx bs=512
+ */
+asmlinkage void mmc_loader(unsigned short *buf, unsigned long len)
+{
+	int high_capacity;
+
+	mmc_init_progress();
+
+	mmc_update_progress(MMC_PROGRESS_ENTER);
+        /* Initialise SDHI1 */
+        /* PORT184CR: GPIO_FN_SDHICMD1 Control */
+        __raw_writeb(CR_FUNCTION1, PORT184CR);
+        /* PORT179CR: GPIO_FN_SDHICLK1 Control */
+        __raw_writeb(CR_INPUT_ENABLE|CR_FUNCTION1, PORT179CR);
+        /* PORT181CR: GPIO_FN_SDHID1_3 Control */
+        __raw_writeb(CR_FUNCTION1, PORT183CR);
+        /* PORT182CR: GPIO_FN_SDHID1_2 Control */
+        __raw_writeb(CR_FUNCTION1, PORT182CR);
+        /* PORT183CR: GPIO_FN_SDHID1_1 Control */
+        __raw_writeb(CR_FUNCTION1, PORT181CR);
+        /* PORT180CR: GPIO_FN_SDHID1_0 Control */
+        __raw_writeb(CR_FUNCTION1, PORT180CR);
+
+        /* Enable clock to SDHI1 hardware block */
+        __raw_writel(__raw_readl(SMSTPCR3) & ~(1 << 13), SMSTPCR3);
+
+	/* setup SDHI hardware */
+	mmc_update_progress(MMC_PROGRESS_INIT);
+	high_capacity = sdhi_boot_init(SDHI_BASE);
+	if (high_capacity < 0)
+		goto err;
+
+	mmc_update_progress(MMC_PROGRESS_LOAD);
+	/* load kernel */
+	if (sdhi_boot_do_read(SDHI_BASE, high_capacity,
+			      0, /* Kernel is at block 1 */
+			      (len + TMIO_BBS - 1) / TMIO_BBS, buf))
+		goto err;
+
+        /* Disable clock to SDHI1 hardware block */
+        __raw_writel(__raw_readl(SMSTPCR3) & (1 << 13), SMSTPCR3);
+
+	mmc_update_progress(MMC_PROGRESS_DONE);
+
+	return;
+err:
+	for(;;);
+}

arch/arm/boot/compressed/sdhi-shmobile.c

+/*
+ * SuperH Mobile SDHI
+ *
+ * Copyright (C) 2010 Magnus Damm
+ * Copyright (C) 2010 Kuninori Morimoto
+ * Copyright (C) 2010 Simon Horman
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Parts inspired by u-boot
+ */
+
+#include <linux/io.h>
+#include <linux/mmc/host.h>
+#include <linux/mmc/core.h>
+#include <linux/mmc/mmc.h>
+#include <linux/mmc/sd.h>
+#include <linux/mmc/tmio.h>
+#include <mach/sdhi.h>
+
+#define OCR_FASTBOOT		(1<<29)
+#define OCR_HCS			(1<<30)
+#define OCR_BUSY		(1<<31)
+
+#define RESP_CMD12		0x00000030
+
+static inline u16 sd_ctrl_read16(void __iomem *base, int addr)
+{
+        return __raw_readw(base + addr);
+}
+
+static inline u32 sd_ctrl_read32(void __iomem *base, int addr)
+{
+	return __raw_readw(base + addr) |
+	       __raw_readw(base + addr + 2) << 16;
+}
+
+static inline void sd_ctrl_write16(void __iomem *base, int addr, u16 val)
+{
+	__raw_writew(val, base + addr);
+}
+
+static inline void sd_ctrl_write32(void __iomem *base, int addr, u32 val)
+{
+	__raw_writew(val, base + addr);
+	__raw_writew(val >> 16, base + addr + 2);
+}
+
+#define ALL_ERROR (TMIO_STAT_CMD_IDX_ERR | TMIO_STAT_CRCFAIL |		\
+		   TMIO_STAT_STOPBIT_ERR | TMIO_STAT_DATATIMEOUT |	\
+		   TMIO_STAT_RXOVERFLOW | TMIO_STAT_TXUNDERRUN |	\
+		   TMIO_STAT_CMDTIMEOUT | TMIO_STAT_ILL_ACCESS |	\
+		   TMIO_STAT_ILL_FUNC)
+
+static int sdhi_intr(void __iomem *base)
+{
+	unsigned long state = sd_ctrl_read32(base, CTL_STATUS);
+
+	if (state & ALL_ERROR) {
+		sd_ctrl_write32(base, CTL_STATUS, ~ALL_ERROR);
+		sd_ctrl_write32(base, CTL_IRQ_MASK,
+				ALL_ERROR |
+				sd_ctrl_read32(base, CTL_IRQ_MASK));
+		return -EINVAL;
+	}
+	if (state & TMIO_STAT_CMDRESPEND) {
+		sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_CMDRESPEND);
+		sd_ctrl_write32(base, CTL_IRQ_MASK,
+				TMIO_STAT_CMDRESPEND |
+				sd_ctrl_read32(base, CTL_IRQ_MASK));
+		return 0;
+	}
+	if (state & TMIO_STAT_RXRDY) {
+		sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_RXRDY);
+		sd_ctrl_write32(base, CTL_IRQ_MASK,
+				TMIO_STAT_RXRDY | TMIO_STAT_TXUNDERRUN |
+				sd_ctrl_read32(base, CTL_IRQ_MASK));
+		return 0;
+	}
+	if (state & TMIO_STAT_DATAEND) {
+		sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_DATAEND);
+		sd_ctrl_write32(base, CTL_IRQ_MASK,
+				TMIO_STAT_DATAEND |
+				sd_ctrl_read32(base, CTL_IRQ_MASK));
+		return 0;
+	}
+
+	return -EAGAIN;
+}
+
+static int sdhi_boot_wait_resp_end(void __iomem *base)
+{
+	int err = -EAGAIN, timeout = 10000000;
+
+	while (timeout--) {
+		err = sdhi_intr(base);
+		if (err != -EAGAIN)
+			break;
+		udelay(1);
+	}
+
+	return err;
+}
+
+/* SDHI_CLK_CTRL */
+#define CLK_MMC_ENABLE                 (1 << 8)
+#define CLK_MMC_INIT                   (1 << 6)        /* clk / 256 */
+
+static void sdhi_boot_mmc_clk_stop(void __iomem *base)
+{
+	sd_ctrl_write16(base, CTL_CLK_AND_WAIT_CTL, 0x0000);
+	msleep(10);
+	sd_ctrl_write16(base, CTL_SD_CARD_CLK_CTL, ~CLK_MMC_ENABLE &
+		sd_ctrl_read16(base, CTL_SD_CARD_CLK_CTL));
+	msleep(10);
+}
+
+static void sdhi_boot_mmc_clk_start(void __iomem *base)
+{
+	sd_ctrl_write16(base, CTL_SD_CARD_CLK_CTL, CLK_MMC_ENABLE |
+		sd_ctrl_read16(base, CTL_SD_CARD_CLK_CTL));
+	msleep(10);
+	sd_ctrl_write16(base, CTL_CLK_AND_WAIT_CTL, CLK_MMC_ENABLE);
+	msleep(10);
+}
+
+static void sdhi_boot_reset(void __iomem *base)
+{
+	sd_ctrl_write16(base, CTL_RESET_SD, 0x0000);
+	msleep(10);
+	sd_ctrl_write16(base, CTL_RESET_SD, 0x0001);
+	msleep(10);
+}
+
+/* Set MMC clock / power.
+ * Note: This controller uses a simple divider scheme therefore it cannot
+ * run a MMC card at full speed (20MHz). The max clock is 24MHz on SD, but as
+ * MMC wont run that fast, it has to be clocked at 12MHz which is the next
+ * slowest setting.
+ */
+static int sdhi_boot_mmc_set_ios(void __iomem *base, struct mmc_ios *ios)
+{
+	if (sd_ctrl_read32(base, CTL_STATUS) & TMIO_STAT_CMD_BUSY)
+		return -EBUSY;
+
+	if (ios->clock)
+		sd_ctrl_write16(base, CTL_SD_CARD_CLK_CTL,
+				ios->clock | CLK_MMC_ENABLE);
+
+	/* Power sequence - OFF -> ON -> UP */
+	switch (ios->power_mode) {
+	case MMC_POWER_OFF: /* power down SD bus */
+		sdhi_boot_mmc_clk_stop(base);
+		break;
+	case MMC_POWER_ON: /* power up SD bus */
+		break;
+	case MMC_POWER_UP: /* start bus clock */
+		sdhi_boot_mmc_clk_start(base);
+		break;
+	}
+
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_1:
+		sd_ctrl_write16(base, CTL_SD_MEM_CARD_OPT, 0x80e0);
+	break;
+	case MMC_BUS_WIDTH_4:
+		sd_ctrl_write16(base, CTL_SD_MEM_CARD_OPT, 0x00e0);
+	break;
+	}
+
+	/* Let things settle. delay taken from winCE driver */
+	udelay(140);
+
+	return 0;
+}
+
+/* These are the bitmasks the tmio chip requires to implement the MMC response
+ * types. Note that R1 and R6 are the same in this scheme. */
+#define RESP_NONE      0x0300
+#define RESP_R1        0x0400
+#define RESP_R1B       0x0500
+#define RESP_R2        0x0600
+#define RESP_R3        0x0700
+#define DATA_PRESENT   0x0800
+#define TRANSFER_READ  0x1000
+
+static int sdhi_boot_request(void __iomem *base, struct mmc_command *cmd)
+{
+	int err, c = cmd->opcode;
+
+	switch (mmc_resp_type(cmd)) {
+	case MMC_RSP_NONE: c |= RESP_NONE; break;
+	case MMC_RSP_R1:   c |= RESP_R1;   break;
+	case MMC_RSP_R1B:  c |= RESP_R1B;  break;
+	case MMC_RSP_R2:   c |= RESP_R2;   break;
+	case MMC_RSP_R3:   c |= RESP_R3;   break;
+	default:
+		return -EINVAL;
+	}
+
+	/* No interrupts so this may not be cleared */
+	sd_ctrl_write32(base, CTL_STATUS, ~TMIO_STAT_CMDRESPEND);
+
+	sd_ctrl_write32(base, CTL_IRQ_MASK, TMIO_STAT_CMDRESPEND |
+			sd_ctrl_read32(base, CTL_IRQ_MASK));
+	sd_ctrl_write32(base, CTL_ARG_REG, cmd->arg);
+	sd_ctrl_write16(base, CTL_SD_CMD, c);
+
+
+	sd_ctrl_write32(base, CTL_IRQ_MASK,
+			~(TMIO_STAT_CMDRESPEND | ALL_ERROR) &
+			sd_ctrl_read32(base, CTL_IRQ_MASK));
+
+	err = sdhi_boot_wait_resp_end(base);
+	if (err)
+		return err;
+
+	cmd->resp[0] = sd_ctrl_read32(base, CTL_RESPONSE);
+
+	return 0;
+}
+
+static int sdhi_boot_do_read_single(void __iomem *base, int high_capacity,
+				    unsigned long block, unsigned short *buf)
+{
+	int err, i;
+
+	/* CMD17 - Read */
+	{
+		struct mmc_command cmd;
+
+		cmd.opcode = MMC_READ_SINGLE_BLOCK | \
+			     TRANSFER_READ | DATA_PRESENT;
+		if (high_capacity)
+			cmd.arg = block;
+		else
+			cmd.arg = block * TMIO_BBS;
+		cmd.flags = MMC_RSP_R1;
+		err = sdhi_boot_request(base, &cmd);
+		if (err)
+			return err;
+	}
+
+	sd_ctrl_write32(base, CTL_IRQ_MASK,
+			~(TMIO_STAT_DATAEND | TMIO_STAT_RXRDY |
+			  TMIO_STAT_TXUNDERRUN) &
+			sd_ctrl_read32(base, CTL_IRQ_MASK));
+	err = sdhi_boot_wait_resp_end(base);
+	if (err)
+		return err;
+
+	sd_ctrl_write16(base, CTL_SD_XFER_LEN, TMIO_BBS);
+	for (i = 0; i < TMIO_BBS / sizeof(*buf); i++)
+		*buf++ = sd_ctrl_read16(base, RESP_CMD12);
+
+	err = sdhi_boot_wait_resp_end(base);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+int sdhi_boot_do_read(void __iomem *base, int high_capacity,
+		      unsigned long offset, unsigned short count,
+		      unsigned short *buf)
+{
+	unsigned long i;
+	int err = 0;
+
+	for (i = 0; i < count; i++) {
+		err = sdhi_boot_do_read_single(base, high_capacity, offset + i,
+					       buf + (i * TMIO_BBS /
+						      sizeof(*buf)));
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+#define VOLTAGES (MMC_VDD_32_33 | MMC_VDD_33_34)
+
+int sdhi_boot_init(void __iomem *base)
+{
+	bool sd_v2 = false, sd_v1_0 = false;
+	unsigned short cid;
+	int err, high_capacity = 0;
+
+	sdhi_boot_mmc_clk_stop(base);
+	sdhi_boot_reset(base);
+
+	/* mmc0: clock 400000Hz busmode 1 powermode 2 cs 0 Vdd 21 width 0 timing 0 */
+	{
+		struct mmc_ios ios;
+		ios.power_mode = MMC_POWER_ON;
+		ios.bus_width = MMC_BUS_WIDTH_1;
+		ios.clock = CLK_MMC_INIT;
+		err = sdhi_boot_mmc_set_ios(base, &ios);
+		if (err)
+			return err;
+	}
+
+	/* CMD0 */
+	{
+		struct mmc_command cmd;
+		msleep(1);
+		cmd.opcode = MMC_GO_IDLE_STATE;
+		cmd.arg = 0;
+		cmd.flags = MMC_RSP_NONE;
+		err = sdhi_boot_request(base, &cmd);
+		if (err)
+			return err;
+		msleep(2);
+	}
+
+	/* CMD8 - Test for SD version 2 */
+	{
+		struct mmc_command cmd;
+		cmd.opcode = SD_SEND_IF_COND;
+		cmd.arg = (VOLTAGES != 0) << 8 | 0xaa;
+		cmd.flags = MMC_RSP_R1;
+		err = sdhi_boot_request(base, &cmd); /* Ignore error */
+		if ((cmd.resp[0] & 0xff) == 0xaa)
+			sd_v2 = true;
+	}
+
+	/* CMD55 - Get OCR (SD) */
+	{
+		int timeout = 1000;
+		struct mmc_command cmd;
+
+		cmd.arg = 0;
+
+		do {
+			cmd.opcode = MMC_APP_CMD;
+			cmd.flags = MMC_RSP_R1;
+			cmd.arg = 0;
+			err = sdhi_boot_request(base, &cmd);
+			if (err)
+				break;
+
+			cmd.opcode = SD_APP_OP_COND;
+			cmd.flags = MMC_RSP_R3;
+			cmd.arg = (VOLTAGES & 0xff8000);
+			if (sd_v2)
+				cmd.arg |= OCR_HCS;
+			cmd.arg |= OCR_FASTBOOT;
+			err = sdhi_boot_request(base, &cmd);
+			if (err)
+				break;
+
+			msleep(1);
+		} while((!(cmd.resp[0] & OCR_BUSY)) && --timeout);
+
+		if (!err && timeout) {
+			if (!sd_v2)
+				sd_v1_0 = true;
+			high_capacity = (cmd.resp[0] & OCR_HCS) == OCR_HCS;
+		}
+	}
+
+	/* CMD1 - Get OCR (MMC) */
+	if (!sd_v2 && !sd_v1_0) {
+		int timeout = 1000;
+		struct mmc_command cmd;
+
+		do {
+			cmd.opcode = MMC_SEND_OP_COND;
+			cmd.arg = VOLTAGES | OCR_HCS;
+			cmd.flags = MMC_RSP_R3;
+			err = sdhi_boot_request(base, &cmd);
+			if (err)
+				return err;
+
+			msleep(1);
+		} while((!(cmd.resp[0] & OCR_BUSY)) && --timeout);
+
+		if (!timeout)
+			return -EAGAIN;
+
+		high_capacity = (cmd.resp[0] & OCR_HCS) == OCR_HCS;
+	}
+
+	/* CMD2 - Get CID */
+	{
+		struct mmc_command cmd;
+		cmd.opcode = MMC_ALL_SEND_CID;
+		cmd.arg = 0;
+		cmd.flags = MMC_RSP_R2;
+		err = sdhi_boot_request(base, &cmd);
+		if (err)
+			return err;
+	}
+
+	/* CMD3
+	 * MMC: Set the relative address
+	 * SD:  Get the relative address
+	 * Also puts the card into the standby state
+	 */
+	{
+		struct mmc_command cmd;
+		cmd.opcode = MMC_SET_RELATIVE_ADDR;
+		cmd.arg = 0;
+		cmd.flags = MMC_RSP_R1;
+		err = sdhi_boot_request(base, &cmd);
+		if (err)
+			return err;
+		cid = cmd.resp[0] >> 16;
+	}
+
+	/* CMD9 - Get CSD */
+	{
+		struct mmc_command cmd;
+		cmd.opcode = MMC_SEND_CSD;
+		cmd.arg = cid << 16;
+		cmd.flags = MMC_RSP_R2;
+		err = sdhi_boot_request(base, &cmd);
+		if (err)
+			return err;
+	}
+
+	/* CMD7 - Select the card */
+	{
+		struct mmc_command cmd;
+		cmd.opcode = MMC_SELECT_CARD;
+		//cmd.arg = rca << 16;
+		cmd.arg = cid << 16;
+		//cmd.flags = MMC_RSP_R1B;
+		cmd.flags = MMC_RSP_R1;
+		err = sdhi_boot_request(base, &cmd);
+		if (err)
+			return err;
+	}
+
+	/* CMD16 - Set the block size */
+	{
+		struct mmc_command cmd;
+		cmd.opcode = MMC_SET_BLOCKLEN;
+		cmd.arg = TMIO_BBS;
+		cmd.flags = MMC_RSP_R1;
+		err = sdhi_boot_request(base, &cmd);
+		if (err)
+			return err;
+	}
+
+	return high_capacity;
+}

arch/arm/boot/compressed/sdhi-shmobile.h

+#ifndef SDHI_MOBILE_H
+#define SDHI_MOBILE_H
+
+#include <linux/compiler.h>
+
+int sdhi_boot_do_read(void __iomem *base, int high_capacity,
+		      unsigned long offset, unsigned short count,
+		      unsigned short *buf);
+int sdhi_boot_init(void __iomem *base);
+
+#endif

arch/arm/mach-shmobile/include/mach/sdhi-sh7372.h

+#ifndef SDHI_SH7372_H
+#define SDHI_SH7372_H
+
+#define SDGENCNTA       0xfe40009c
+
+/* The countdown of SDGENCNTA is controlled by
+ * ZB3D2CLK which runs at 149.5MHz.
+ * That is 149.5ticks/us. Approximate this as 150ticks/us.
+ */
+static void udelay(int us)
+{
+	__raw_writel(us * 150, SDGENCNTA);
+	while(__raw_readl(SDGENCNTA)) ;
+}
+
+static void msleep(int ms)
+{
+	udelay(ms * 1000);
+}
+
+#endif

arch/arm/mach-shmobile/include/mach/sdhi.h

+#ifndef SDHI_H
+#define SDHI_H
+
+/**************************************************
+ *
+ *		CPU specific settings
+ *
+ **************************************************/
+
+#ifdef CONFIG_ARCH_SH7372
+#include "mach/sdhi-sh7372.h"
+#else
+#error "unsupported CPU."
+#endif
+
+#endif /* SDHI_H */