sunxi: Create helper function veryfing valid boot signature on MMC

Make possible using single u-boot-sunxi-with-spl.bin binary for both NAND memory and SD card. Detection where SPL was read from is implemented in spl_boot_device.

V2:
- Move signature verification to helper function
- Avoid unnecessary condition nesting

V3:
- Further simplification of conditions
- Move reassigning mmc block.dev numbers from board_mmc_init to spl_boot_device
- If signature wasn't found on mmc0 and SPL_NAND_SUPPORT isn't enabled don't assume mmc2 is a valid boot device - check for egon signature first

Signed-off-by Daniel Kochma?ski <[email protected]>

CC Roy Spliet <[email protected]>

Cc Ian Campbell <[email protected]>

Cc Hans De Goede <[email protected]>

---
  arch/arm/cpu/armv7/sunxi/board.c | 63 ++++++++++++++++++++++++++--------------
  1 file changed, 41 insertions(+), 22 deletions(-)

arch/arm/cpu/armv7/sunxi/board.c +41 -22

index a82c8b9..c06922c 100644
@@ -11,6 +11,7 @@
   */
 
  #include <common.h>
+#include <mmc.h>
  #include <i2c.h>
  #include <serial.h>
  #ifdef CONFIG_SPL_BUILD

@@ -22,6 +23,7 @@
  #include <asm/arch/gpio.h>
  #include <asm/arch/sys_proto.h>
  #include <asm/arch/timer.h>
+#include <asm/arch/mmc.h>
 
  #include <linux/compiler.h>
 

@@ -117,26 +119,18 @@ void s_init(void)
  }
 
  #ifdef CONFIG_SPL_BUILD
+DECLARE_GLOBAL_DATA_PTR;
+
  /* The sunxi internal brom will try to loader external bootloader
   * from mmc0, nand flash, mmc2.
- *
- * Unfortunately we can't check how SPL was loaded so assume it's
- * always the first SD/MMC controller, unless it was explicitly
- * stated that SPL is on nand flash.
   */
  u32 spl_boot_device(void)
  {
-#if defined(CONFIG_SPL_NAND_SUPPORT)
+	struct mmc *mmc0, *mmc1;
  	/*
-	 * This is compile time configuration informing SPL, that it
-	 * was loaded from nand flash.
-	 */
-	return BOOT_DEVICE_NAND;
-#else
-	/*
-	 * When booting from the SD card, the "eGON.BT0" signature is expected
-	 * to be found in memory at the address 0x0004 (see the "mksunxiboot"
-	 * tool, which generates this header).
+	 * When booting from the SD card or NAND memory, the "eGON.BT0"
+	 * signature is expected to be found in memory at the address 0x0004
+	 * (see the "mksunxiboot" tool, which generates this header).
  	 *
  	 * When booting in the FEL mode over USB, this signature is patched in
  	 * memory and replaced with something else by the 'fel' tool. This other

@@ -144,16 +138,41 @@ u32 spl_boot_device(void)
  	 * valid bootable SD card image (because the BROM would refuse to
  	 * execute the SPL in this case).
  	 *
-	 * This branch is just making a decision at runtime whether to load
-	 * the main u-boot binary from the SD card (if the "eGON.BT0" signature
-	 * is found) or return to the FEL code in the BROM to wait and receive
-	 * the main u-boot binary over USB.
+	 * This checks for the signature and if it is not found returns to
+	 * the FEL code in the BROM to wait and receive the main u-boot
+	 * binary over USB. If it is found, it determines where SPL was
+	 * read from.
  	 */
-	if (readl(4) == 0x4E4F4765 && readl(8) == 0x3054422E) /* eGON.BT0 */
-		return BOOT_DEVICE_MMC1;
-	else
+	if (readl(4) != 0x4E4F4765 || readl(8) != 0x3054422E) /* eGON.BT0 */
  		return BOOT_DEVICE_BOARD;
-#endif
+
+	/* The BROM will try to boot from mmc0 first, so try that first. */
+	mmc_initialize(gd->bd);
+	mmc0 = find_mmc_device(0);
+	if (sunxi_mmc_has_egon_boot_signature(mmc0))
+		return BOOT_DEVICE_MMC1;
+
+	/* Fallback to booting NAND if enabled. */
+	if (IS_ENABLED(CONFIG_SPL_NAND_SUPPORT))
+		return BOOT_DEVICE_NAND;
+
+	if (IS_ENABLED(CONFIG_MMC_SUNXI_SLOT_EXTRA) &&
+	    CONFIG_MMC_SUNXI_SLOT_EXTRA == 2)
+	{
+		mmc1 = find_mmc_device(1);
+		if (sunxi_mmc_has_egon_boot_signature(mmc1))
+		{
+			/* spl_mmc.c: spl_mmc_load_image() is hard-coded to
+			 * use find_mmc_device(0), no matter what we
+			 * return. Swap mmc0 and mmc2 to make this work. */
+			mmc0->block_dev.dev = 1;
+			mmc1->block_dev.dev = 0;
+			return BOOT_DEVICE_MMC2
+		}
+	}
+
+	panic("Could not determine boot source\n");
+	return -1;		/* Never reached */
  }
 
  /* No confirmation data available in SPL yet. Hardcode bootmode */

mmc_initialize might be called from various places and initializing list head of mmc_devices can lead to memory leaks.

Signed-off-by Daniel Kochma?ski <[email protected]>

CC Roy Spliet <[email protected]>

Cc Ian Campbell <[email protected]>

Cc Hans De Goede <[email protected]>

CC Pantelis Antoniou <[email protected]>

---
  drivers/mmc/mmc.c | 5 +++++
  1 file changed, 5 insertions(+)

drivers/mmc/mmc.c +5 -0

index 79e6fee..2959bde 100644
@@ -1758,6 +1758,11 @@ static void do_preinit(void)
 
  int mmc_initialize(bd_t *bis)
  {
+	static int initialized = 0;
+	if (initialized)	/* Avoid initializing mmc multiple times */
+		return 0;
+	initialized = 1;
+
  	INIT_LIST_HEAD (&mmc_devices);
  	cur_dev_num = 0;
 

This patch extracts checking for valid SD card "eGON.BT0" signature from board_mmc_init into function sunxi_mmc_has_egon_boot_signature.

Buffer for mmc sector is allocated and freed at runtime. panic is triggered on malloc failure.

Signed-off-by Daniel Kochma?ski <[email protected]>

CC Roy Spliet <[email protected]>

Cc Ian Campbell <[email protected]>

Cc Hans De Goede <[email protected]>

---
  arch/arm/include/asm/arch-sunxi/mmc.h |  1 +
  board/sunxi/board.c                   |  8 ++------
  drivers/mmc/sunxi_mmc.c               | 17 +++++++++++++++++
  3 files changed, 20 insertions(+), 6 deletions(-)

arch/arm/include/asm/arch-sunxi/mmc.h +1 -0

index cb52e64..3da360b 100644
@@ -127,4 +127,5 @@ struct sunxi_mmc {
  #define SUNXI_MMC_COMMON_RESET			(1 << 18)
 
  struct mmc *sunxi_mmc_init(int sdc_no);
+int sunxi_mmc_has_egon_boot_signature(struct mmc *mmc);
  #endif /* _SUNXI_MMC_H */

board/sunxi/board.c +2 -6

index 3f23f26..dc95431 100644
@@ -302,12 +302,8 @@ int board_mmc_init(bd_t *bis)
  	 * Both mmc0 and mmc2 are bootable, figure out where we're booting
  	 * from. Try mmc0 first, just like the brom does.
  	 */
-	if (mmc_getcd(mmc0) && mmc_init(mmc0) == 0 &&
-	    mmc0->block_dev.block_read(0, 16, 1, buf) == 1) {
-		buf[12] = 0;
-		if (strcmp(&buf[4], "eGON.BT0") == 0)
-			return 0;
-	}
+	if (sunxi_mmc_has_egon_boot_signature(mmc0))
+		return 0;
 
  	/* no bootable card in mmc0, so we must be booting from mmc2, swap */
  	mmc0->block_dev.dev = 1;

drivers/mmc/sunxi_mmc.c +17 -0

index bb08147..ef3e84c 100644
@@ -431,6 +431,23 @@ static int sunxi_mmc_getcd(struct mmc *mmc)
  	return !gpio_get_value(cd_pin);
  }
 
+int sunxi_mmc_has_egon_boot_signature(struct mmc *mmc)
+{
+	char *buf = malloc(512);
+	int valid_signature = 0;
+
+	if (buf == NULL)
+		panic("Failed to allocate memory\n");
+
+	if (mmc_getcd(mmc) && mmc_init(mmc) == 0 &&
+	    mmc->block_dev.block_read(0, 16, 1, buf) == 1 &&
+	    strncmp(&buf[4], "eGON.BT0", 8) == 0)
+		valid_signature = 1;
+
+	free(buf);
+	return valid_signature;
+}
+
  static const struct mmc_ops sunxi_mmc_ops = {
  	.send_cmd	= sunxi_mmc_send_cmd,
  	.set_ios	= sunxi_mmc_set_ios,