vbe: Create a common function to get the block device

Add a vbe_get_blk() function and use it to obtain the block device used
by VBE.

Signed-off-by: Simon Glass <[email protected]>

4 files changed, 54 insertions, 20 deletions

diff --git a/boot/Makefile b/boot/Makefile
index a24fd90c510..c2753de8163 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -65,7 +65,7 @@ endif
 
 obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE) += vbe.o
 obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE_REQUEST) += vbe_request.o
-obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o
+obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE_SIMPLE) += vbe_simple.o vbe_common.o
 obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE_SIMPLE_FW) += vbe_simple_fw.o
 obj-$(CONFIG_$(PHASE_)BOOTMETH_VBE_SIMPLE_OS) += vbe_simple_os.o
 
diff --git a/boot/vbe_common.c b/boot/vbe_common.c
new file mode 100644
index 00000000000..ede452ba306
--- /dev/null
+++ b/boot/vbe_common.c
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Verified Boot for Embedded (VBE) common functions
+ *
+ * Copyright 2024 Google LLC
+ * Written by Simon Glass <[email protected]>
+ */
+
+#include <part.h>
+#include <vsprintf.h>
+#include "vbe_common.h"
+
+int vbe_get_blk(const char *storage, struct udevice **blkp)
+{
+	struct blk_desc *desc;
+	char devname[16];
+	const char *end;
+	int devnum;
+
+	/* First figure out the block device */
+	log_debug("storage=%s\n", storage);
+	devnum = trailing_strtoln_end(storage, NULL, &end);
+	if (devnum == -1)
+		return log_msg_ret("num", -ENODEV);
+	if (end - storage >= sizeof(devname))
+		return log_msg_ret("end", -E2BIG);
+	strlcpy(devname, storage, end - storage + 1);
+	log_debug("dev=%s, %x\n", devname, devnum);
+
+	desc = blk_get_dev(devname, devnum);
+	if (!desc)
+		return log_msg_ret("get", -ENXIO);
+	*blkp = desc->bdev;
+
+	return 0;
+}
diff --git a/boot/vbe_common.h b/boot/vbe_common.h
index 1fc70ee74c8..0cd9617b5b1 100644
--- a/boot/vbe_common.h
+++ b/boot/vbe_common.h
@@ -48,4 +48,17 @@ struct vbe_nvdata {
 	u8 spare2[0x34];
 };
 
+/**
+ * vbe_get_blk() - Obtain the block device to use for VBE
+ *
+ * Decodes the string to produce a block device
+ *
+ * @storage: String indicating the device to use, e.g. "mmc1"
+ * @blkp: Returns associated block device, on success
+ * Return 0 if OK, -ENODEV if @storage does not end with a number, -E2BIG if
+ * the device name is more than 15 characters, -ENXIO if the block device could
+ * not be found
+ */
+int vbe_get_blk(const char *storage, struct udevice **blkp);
+
 #endif /* __VBE_ABREC_H */
diff --git a/boot/vbe_simple.c b/boot/vbe_simple.c
index 313f063fa18..8a370cf02ef 100644
--- a/boot/vbe_simple.c
+++ b/boot/vbe_simple.c
@@ -98,28 +98,13 @@ int vbe_simple_read_state(struct udevice *dev, struct simple_state *state)
 {
 	ALLOC_CACHE_ALIGN_BUFFER(u8, buf, MMC_MAX_BLOCK_LEN);
 	struct simple_priv *priv = dev_get_priv(dev);
-	struct blk_desc *desc;
 	struct udevice *blk;
-	char devname[16];
-	const char *end;
-	int devnum;
 	int ret;
 
-	/* First figure out the block device */
-	log_debug("storage=%s\n", priv->storage);
-	devnum = trailing_strtoln_end(priv->storage, NULL, &end);
-	if (devnum == -1)
-		return log_msg_ret("num", -ENODEV);
-	if (end - priv->storage >= sizeof(devname))
-		return log_msg_ret("end", -E2BIG);
-	strlcpy(devname, priv->storage, end - priv->storage + 1);
-	log_debug("dev=%s, %x\n", devname, devnum);
-
-	desc = blk_get_dev(devname, devnum);
-	if (!desc)
-		return log_msg_ret("get", -ENXIO);
-
-	blk = desc->bdev;
+	ret = vbe_get_blk(priv->storage, &blk);
+	if (ret)
+		return log_msg_ret("blk", ret);
+
 	ret = simple_read_version(priv, blk, buf, state);
 	if (ret)
 		return log_msg_ret("ver", ret);