bootstd: support scanning a single partition

The "bootflow" command currently doesn't support scanning a single
partition. This is inconvenient in setups with multiple bootable
partitions within a single disk, but only one is desired.

Support scanning a single disk partition. Specifically, support the
syntax:
	bootflow scan mmc1:4
which scans only mmc device 1, partition 4.

Signed-off-by: Nam Cao <namcao@linutronix.de>

diff --git a/boot/bootdev-uclass.c b/boot/bootdev-uclass.c
index 0fa6dad8b11bf65f00d87fe25f4647b425170b13..46815ea2fdbfc4964a39932a7b9032916af8d333 100644 (file)
--- a/boot/bootdev-uclass.c
+++ b/boot/bootdev-uclass.c
@@ -172,8 +172,10 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
         */
        iter->max_part = MAX_PART_PER_BOOTDEV;
 
-       /* If this is the whole disk, check if we have bootable partitions */
-       if (!iter->part) {
+       if (iter->flags & BOOTFLOWIF_SINGLE_PARTITION) {
+               /* a particular partition was specified, scan it without checking */
+       } else if (!iter->part) {
+               /* This is the whole disk, check if we have bootable partitions */
                iter->first_bootable = part_get_bootable(desc);
                log_debug("checking bootable=%d\n", iter->first_bootable);
        } else if (allow_any_part) {
@@ -710,8 +712,37 @@ int bootdev_setup_iter(struct bootflow_iter *iter, const char *label,
        struct udevice *bootstd, *dev = NULL;
        bool show = iter->flags & BOOTFLOWIF_SHOW;
        int method_flags;
+       char buf[32];
        int ret;
 
+       if (label) {
+               const char *end = strchr(label, ':');
+
+               if (end) {
+                       size_t len = (size_t)(end - label);
+                       const char *part = end + 1;
+
+                       if (len + 1 > sizeof(buf)) {
+                               log_err("label \"%s\" is way too long\n", label);
+                               return -EINVAL;
+                       }
+
+                       memcpy(buf, label, len);
+                       buf[len] = '\0';
+                       label = buf;
+
+                       unsigned long tmp;
+
+                       if (strict_strtoul(part, 0, &tmp)) {
+                               log_err("Invalid partition number: %s\n", part);
+                               return -EINVAL;
+                       }
+
+                       iter->flags |= BOOTFLOWIF_SINGLE_PARTITION;
+                       iter->part = tmp;
+               }
+       }
+
        ret = uclass_first_device_err(UCLASS_BOOTSTD, &bootstd);
        if (ret) {
                log_err("Missing bootstd device\n");

diff --git a/boot/bootflow.c b/boot/bootflow.c
index 05484fd5b1b98bebb431b0a8579ea61c720f526a..68bf99329ab0df7b579dad37cce9d34aeb80b642 100644 (file)
--- a/boot/bootflow.c
+++ b/boot/bootflow.c
@@ -217,6 +217,9 @@ static int iter_incr(struct bootflow_iter *iter)
                }
        }
 
+       if (iter->flags & BOOTFLOWIF_SINGLE_PARTITION)
+               return BF_NO_MORE_DEVICES;
+
        /* No more bootmeths; start at the first one, and... */
        iter->cur_method = 0;
        iter->method = iter->method_order[iter->cur_method];

diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
index 496e24bc7a61f4a73e1e4173bc6753b66b8fd1b2..a07a72581e7ad9a556a325555987c36c1c457d4e 100644 (file)
--- a/doc/develop/bootstd.rst
+++ b/doc/develop/bootstd.rst
@@ -531,6 +531,10 @@ Then the iterator is set up to according to the parameters given:
     `BOOTFLOWIF_SINGLE_MEDIA` is set. In this case, moving to the next bootdev
     processes just the children of the media device. Hunters are used, in this
     example just the "mmc" hunter.
+  - If `label` indicates a particular partition in a particular media device
+    (e.g. "mmc1:3") then `BOOTFLOWIF_SINGLE_PARTITION` is set. In this case,
+    only a single partition within a bootdev is processed. Hunters are used, in
+    this example just the "mmc" hunter.
   - If `label` indicates a media uclass (e.g. "mmc") then
     `BOOTFLOWIF_SINGLE_UCLASS` is set. In this case, all bootdevs in that uclass
     are used. Hunters are used, in this example just the "mmc" hunter

diff --git a/include/bootflow.h b/include/bootflow.h
index 42112874f647c2e0bc7ac32c32a73606595b811e..080ee850122556ed15735cbccdbb27f42b3ef680 100644 (file)
--- a/include/bootflow.h
+++ b/include/bootflow.h
@@ -133,6 +133,8 @@ struct bootflow {
  * this uclass (used with things like "mmc")
  * @BOOTFLOWIF_SINGLE_MEDIA: (internal) Scan one media device in the uclass (used
  * with things like "mmc1")
+ * @BOOTFLOWIF_SINGLE_PARTITION: (internal) Scan one partition in media device
+ * (used with things like "mmc1:3")
  */
 enum bootflow_iter_flags_t {
        BOOTFLOWIF_FIXED                = 1 << 0,
@@ -148,6 +150,7 @@ enum bootflow_iter_flags_t {
        BOOTFLOWIF_SKIP_GLOBAL          = 1 << 17,
        BOOTFLOWIF_SINGLE_UCLASS        = 1 << 18,
        BOOTFLOWIF_SINGLE_MEDIA         = 1 << 19,
+       BOOTFLOWIF_SINGLE_PARTITION     = 1 << 20,
 };
 
 /**