[PATCH v1 3/3] arm: xea: Add support for boot image source descriptor in SPL

[Lukasz Majewski <lukma@denx.de>]

From: Anatolij Gustschin <agust@denx.de>

We load two boot image source descriptor structures from last
two sectors in the SPI NOR flash and determine the boot source
for loading the kernel/DTB images, then adjust the boot order for
loading image from eMMC boot0 or boot1 partition.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Lukasz Majewski <lukma@denx.de>

---

 board/liebherr/xea/boot_img_scr.h | 27 ++++++++++
 board/liebherr/xea/xea.c          | 85 +++++++++++++++++++++++++++++++
 2 files changed, 112 insertions(+)
 create mode 100644 board/liebherr/xea/boot_img_scr.h

diff --git a/board/liebherr/xea/boot_img_scr.h b/board/liebherr/xea/boot_img_scr.h
new file mode 100644
index 0000000000..baa3072b49
--- /dev/null
+++ b/board/liebherr/xea/boot_img_scr.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier:     GPL-2.0+ */
+/*
+ * Struct for boot image source description for placing in last
+ * two SPI NOR flash sectors on legcom.
+ */
+
+struct boot_img_src {
+	u8 magic;	/* Must be 'B' = 0x42 */
+	u8 flags;	/* flags to specify mmcblk[0|1] boot[0|1] */
+	u8 crc8;	/* CRC-8 over above two bytes */
+} __packed;
+
+/*
+ * Bit definition in boot_img_src.flags:
+ *  Bit 0: mmcblk device 0 or 1 (1 - if this bit set)
+ *  Bit 1: mmcblk boot partition 0 or 1.
+ *         for eMMC: boot0 if this bit is cleared, boot1 - if set
+ *         for SD-card the boot partition value will always be 0
+ *         (independent of the value of this bit)
+ *
+ */
+#define BOOT_SRC_MMC1	BIT(0)
+#define BOOT_SRC_PART1	BIT(1)
+
+/* Offset of the first boot image source descriptor in SPI NOR */
+#define SPI_FLASH_BOOT_SRC_OFFS	0xFE0000
+#define SPI_FLASH_SECTOR_SIZE	0x10000
diff --git a/board/liebherr/xea/xea.c b/board/liebherr/xea/xea.c
index e4d2eb65cc..c8ac526cb4 100644
--- a/board/liebherr/xea/xea.c
+++ b/board/liebherr/xea/xea.c
@@ -32,6 +32,11 @@
 #include <errno.h>
 #include <usb.h>
 #include <serial.h>
+#include <u-boot/crc.h>
+#include "boot_img_scr.h"
+
+#include <spi.h>
+#include <spi_flash.h>
 
 #ifdef CONFIG_SPL_BUILD
 #include <spl.h>
@@ -66,6 +71,52 @@ void board_init_f(ulong arg)
 	preloader_console_init();
 }
 
+static struct boot_img_src img_src[2];
+static int spi_load_boot_info(void)
+{
+	struct spi_flash *flash;
+	int err;
+
+	flash = spi_flash_probe(CONFIG_SF_DEFAULT_BUS,
+				CONFIG_SF_DEFAULT_CS,
+				CONFIG_SF_DEFAULT_SPEED,
+				CONFIG_SF_DEFAULT_MODE);
+	if (!flash) {
+		printf("%s: SPI probe err\n", __func__);
+		return -ENODEV;
+	}
+
+	/*
+	 * Load both boot info structs from SPI flash
+	 */
+	err = spi_flash_read(flash, SPI_FLASH_BOOT_SRC_OFFS,
+			     sizeof(img_src[0]),
+			     (void *)&img_src[0]);
+	if (err) {
+		debug("%s: First boot info NOR sector read error %d\n",
+		      __func__, err);
+		return err;
+	}
+
+	err = spi_flash_read(flash,
+			     SPI_FLASH_BOOT_SRC_OFFS + SPI_FLASH_SECTOR_SIZE,
+			     sizeof(img_src[0]),
+			     (void *)&img_src[1]);
+	if (err) {
+		debug("%s: First boot info NOR sector read error %d\n",
+		      __func__, err);
+		return err;
+	}
+
+	debug("%s: BI0 0x%x 0x%x 0x%x\n", __func__,
+	      img_src[0].magic, img_src[0].flags, img_src[0].crc8);
+
+	debug("%s: BI1 0x%x 0x%x 0x%x\n", __func__,
+	      img_src[1].magic, img_src[1].flags, img_src[1].crc8);
+
+	return 0;
+}
+
 static int boot_tiva0, boot_tiva1;
 
 /* Check if TIVAs request booting via U-Boot proper */
@@ -114,6 +165,40 @@ void spl_board_init(void)
 	boot_tiva1 = dm_gpio_get_value(&btiva1);
 }
 
+int spl_mmc_emmc_boot_partition(struct mmc *mmc)
+{
+	int i, src_idx = -1, ret;
+
+	ret = spi_load_boot_info();
+	if (ret) {
+		printf("%s: Cannot read XEA boot info! [%d]\n", __func__, ret);
+		/* To avoid bricking board - by default boot from boot0 eMMC */
+		return 1;
+	}
+
+	for (i = 0; i < 2; i++) {
+		if (img_src[i].magic == 'B' &&
+		    img_src[i].crc8 == crc8(0, &img_src[i].magic, 2)) {
+			src_idx = i;
+			break;
+		}
+	}
+
+	debug("%s: src idx: %d\n", __func__, src_idx);
+
+	if (src_idx < 0)
+		/*
+		 * Always use eMMC (mmcblkX) boot0 if no
+		 * valid image source description found
+		 */
+		return 1;
+
+	if (img_src[src_idx].flags & BOOT_SRC_PART1)
+		return 2;
+
+	return 1;
+}
+
 void board_boot_order(u32 *spl_boot_list)
 {
 	spl_boot_list[0] = BOOT_DEVICE_MMC1;
-- 
2.39.2