[PATCH 2/4] spl: ufs: add Falcon mode load path

[Alexey Charkov]

In Falcon mode, the SPL loads a FIT image containing a Linux kernel
instead of U-boot proper, and it may need to fall back to loading U-boot
if Linux is unavailable.

Add support for images containing a Linux kernel, optionally on a
different UFS LUN and/or offset vs. U-boot proper to enable fallback.

Signed-off-by: Alexey Charkov <alchark at flipper.net>
---
 common/spl/Kconfig   | 18 +++++++++++++++++
 common/spl/spl_ufs.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++++--
 2 files changed, 73 insertions(+), 2 deletions(-)

diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index cc819344cad2..2ce48eb981d2 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -1635,6 +1635,16 @@ config SPL_UFS_RAW_U_BOOT_DEVNUM
 	  SCSI device number, which might differ from the UFS LUN if you have
 	  multiple SCSI devices attached and recognized by the SPL.
 
+config SPL_UFS_RAW_OS_DEVNUM
+	int "Falcon mode: SCSI device number of the UFS device to load OS from"
+	depends on SPL_UFS_SUPPORT && SPL_OS_BOOT
+	default SPL_UFS_RAW_U_BOOT_DEVNUM
+	help
+	  UFS devices are usually configured with multiple LUNs, which present
+	  themselves as sequentially numbered SCSI devices. This option controls
+	  which of them SPL will attempt to load a Falcon OS payload from.
+	  It allows putting Linux FITs on a different UFS LU than U-Boot.
+
 config SPL_UFS_RAW_U_BOOT_SECTOR
 	hex "Address on the UFS to load U-Boot from"
 	depends on SPL_UFS_SUPPORT
@@ -1643,6 +1653,14 @@ config SPL_UFS_RAW_U_BOOT_SECTOR
 	  Address on the block device to load U-Boot from.
 	  Units: UFS sectors (1 sector = 4096 bytes).
 
+config SPL_UFS_RAW_OS_SECTOR
+	hex "Falcon mode: address on the UFS to load OS image from"
+	depends on SPL_UFS_SUPPORT && SPL_OS_BOOT
+	default SPL_UFS_RAW_U_BOOT_SECTOR
+	help
+	  Address on the block device to load a Falcon OS FIT/image from.
+	  Units: UFS sectors (1 sector = 4096 bytes).
+
 config SPL_WATCHDOG
 	bool "Support watchdog drivers"
 	imply SPL_WDT if !HW_WATCHDOG
diff --git a/common/spl/spl_ufs.c b/common/spl/spl_ufs.c
index cef1843f40f3..5c7ec869ab0c 100644
--- a/common/spl/spl_ufs.c
+++ b/common/spl/spl_ufs.c
@@ -20,13 +20,37 @@ static ulong spl_ufs_load_read(struct spl_load_info *load, ulong off, ulong size
 	return blk_dread(bd, sector, count, buf) << bd->log2blksz;
 }
 
+static int spl_ufs_load_image_raw_os(struct spl_image_info *spl_image,
+				     struct spl_boot_device *bootdev,
+				     struct spl_load_info *load,
+				     struct blk_desc *bd)
+{
+	ulong sector = config_opt_enabled(CONFIG_SPL_OS_BOOT,
+					  CONFIG_SPL_UFS_RAW_OS_SECTOR, 0);
+	int err;
+
+	err = spl_load(spl_image, bootdev, load, 0,
+		       sector << bd->log2blksz);
+	if (err)
+		return err;
+
+	if (spl_image->os != IH_OS_LINUX && spl_image->os != IH_OS_TEE &&
+	    spl_image->os != IH_OS_ARM_TRUSTED_FIRMWARE) {
+		puts("Expected OS image is not found\n");
+		return -ENOENT;
+	}
+
+	return 0;
+}
+
 static int spl_ufs_load_image(struct spl_image_info *spl_image,
 			      struct spl_boot_device *bootdev)
 {
 	unsigned long sector = CONFIG_SPL_UFS_RAW_U_BOOT_SECTOR;
 	int devnum = CONFIG_SPL_UFS_RAW_U_BOOT_DEVNUM;
-	struct spl_load_info load;
-	struct blk_desc *bd;
+	int os_devnum;
+	struct spl_load_info load, os_load;
+	struct blk_desc *bd, *os_bd;
 	int err;
 
 	/* try to recognize storage devices immediately */
@@ -36,6 +60,35 @@ static int spl_ufs_load_image(struct spl_image_info *spl_image,
 		return -ENODEV;
 
 	spl_load_init(&load, spl_ufs_load_read, bd, bd->blksz);
+	if (IS_ENABLED(CONFIG_SPL_OS_BOOT) && !spl_start_uboot()) {
+		os_devnum = config_opt_enabled(CONFIG_SPL_OS_BOOT,
+					       CONFIG_SPL_UFS_RAW_OS_DEVNUM,
+					       CONFIG_SPL_UFS_RAW_U_BOOT_DEVNUM);
+		if (os_devnum == devnum) {
+			os_bd = bd;
+			os_load = load;
+		} else {
+			os_bd = blk_get_devnum_by_uclass_id(UCLASS_SCSI, os_devnum);
+			if (!os_bd) {
+				puts("spl_ufs_load_image: UFS OS device not found\n");
+				if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+					return -ENODEV;
+				goto load_uboot;
+			}
+			spl_load_init(&os_load, spl_ufs_load_read, os_bd, os_bd->blksz);
+		}
+
+		err = spl_ufs_load_image_raw_os(spl_image, bootdev, &os_load, os_bd);
+		if (!err)
+			return 0;
+
+		puts("spl_ufs_load_image: Failed to load falcon payload\n");
+		log_debug("(error=%d)\n", err);
+		if (IS_ENABLED(CONFIG_SPL_OS_BOOT_SECURE))
+			return err;
+	}
+
+load_uboot:
 	err = spl_load(spl_image, bootdev, &load, 0, sector << bd->log2blksz);
 	if (err) {
 		puts("spl_ufs_load_image: ufs block read error\n");

-- 
2.53.0