Some bootmeths support scanning a partition without a filesystem on it.
Add a flag to support this.
This will allow the ChromiumOS bootmeth to find kernel partition, which
are stored in a special format, without a filesystem.
Signed-off-by: Simon Glass <s...@chromium.org>
---
boot/bootdev-uclass.c | 17 ++++++++++++++---
doc/develop/bootstd.rst | 11 ++++++-----
include/bootmeth.h | 3 +++
3 files changed, 23 insertions(+), 8 deletions(-)
diff --git a/boot/bootdev-uclass.c b/boot/bootdev-uclass.c
index 00dc28e623a2..eab89088b63d 100644
--- a/boot/bootdev-uclass.c
+++ b/boot/bootdev-uclass.c
@@ -111,6 +111,8 @@ int bootdev_bind(struct udevice *parent, const char
*drv_name, const char *name,
int bootdev_find_in_blk(struct udevice *dev, struct udevice *blk,
struct bootflow_iter *iter, struct bootflow *bflow)
{
+ struct bootmeth_uc_plat *plat = dev_get_uclass_plat(bflow->method);
+ bool allow_any_part = plat->flags & BOOTMETHF_ANY_PART;
struct blk_desc *desc = dev_get_uclass_plat(blk);
struct disk_partition info;
char partstr[20];
@@ -142,6 +144,7 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice
*blk,
* us whether there is valid media there
*/
ret = part_get_info(desc, iter->part, &info);
+ log_debug("part_get_info() returned %d\n", ret);
if (!iter->part && ret == -ENOENT)
ret = 0;
@@ -154,7 +157,7 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice
*blk,
ret = -ESHUTDOWN;
else
bflow->state = BOOTFLOWST_MEDIA;
- if (ret) {
+ if (ret && !allow_any_part) {
/* allow partition 1 to be missing */
if (iter->part == 1) {
iter->max_part = 3;
@@ -174,9 +177,15 @@ int bootdev_find_in_blk(struct udevice *dev, struct
udevice *blk,
if (!iter->part) {
iter->first_bootable = part_get_bootable(desc);
log_debug("checking bootable=%d\n", iter->first_bootable);
+ } else if (allow_any_part) {
+ /*
+ * allow any partition to be scanned, by skipping any checks
+ * for filesystems or partition contents on this disk
+ */
/* if there are bootable partitions, scan only those */
- } else if (iter->first_bootable ? !info.bootable : iter->part != 1) {
+ } else if (iter->first_bootable >= 0 &&
+ (iter->first_bootable ? !info.bootable : iter->part != 1)) {
return log_msg_ret("boot", -EINVAL);
} else {
ret = fs_set_blk_dev_with_part(desc, bflow->part);
@@ -193,6 +202,7 @@ int bootdev_find_in_blk(struct udevice *dev, struct udevice
*blk,
bflow->state = BOOTFLOWST_FS;
}
+ log_debug("method %s\n", bflow->method->name);
ret = bootmeth_read_bootflow(bflow->method, bflow);
if (ret)
return log_msg_ret("method", ret);
@@ -555,7 +565,8 @@ int bootdev_get_bootflow(struct udevice *dev, struct
bootflow_iter *iter,
{
const struct bootdev_ops *ops = bootdev_get_ops(dev);
- log_debug("->get_bootflow %s=%p\n", dev->name, ops->get_bootflow);
+ log_debug("->get_bootflow %s,%x=%p\n", dev->name, iter->part,
+ ops->get_bootflow);
bootflow_init(bflow, dev, iter->method);
if (!ops->get_bootflow)
return default_get_bootflow(dev, iter, bflow);
diff --git a/doc/develop/bootstd.rst b/doc/develop/bootstd.rst
index 7a2a69fdfcec..23ea46d6c304 100644
--- a/doc/develop/bootstd.rst
+++ b/doc/develop/bootstd.rst
@@ -677,11 +677,12 @@ Assuming the bootmeth is happy, or at least indicates
that it is willing to try
partition. If that works it tries to detect a file system. If that works then
it
calls the bootmeth device once more, this time to read the bootflow.
-Note: At present a filesystem is needed for the bootmeth to be called on block
-devices, simply because we don't have any examples where this is not the case.
-This feature can be added as needed. Note that sandbox is a special case, since
-in that case the host filesystem can be accessed even though the block device
-is NULL.
+Note: Normally a filesystem is needed for the bootmeth to be called on block
+devices, but bootmeths which don't need that can set the BOOTMETHF_ANY_PART
+flag to indicate that they can scan any partition. An example is the ChromiumOS
+bootmeth which can store a kernel in a raw partition. Note also that sandbox is
+a special case, since in that case the host filesystem can be accessed even
+though the block device is NULL.
If we take the example of the `bootmeth_extlinux` driver, this call ends up at
`extlinux_read_bootflow()`. It has the filesystem ready, so tries various
diff --git a/include/bootmeth.h b/include/bootmeth.h
index d3d8d608cd78..0fc36104ece0 100644
--- a/include/bootmeth.h
+++ b/include/bootmeth.h
@@ -16,9 +16,12 @@ struct udevice;
* enum bootmeth_flags - Flags for bootmeths
*
* @BOOTMETHF_GLOBAL: bootmeth handles bootdev selection automatically
+ * @BOOTMETHF_ANY_PART: bootmeth is willing to check any partition, even if it
+ * has no filesystem
*/
enum bootmeth_flags {
BOOTMETHF_GLOBAL = BIT(0),
+ BOOTMETHF_ANY_PART = BIT(1),
};
/**
--
2.41.0.640.ga95def55d0-goog
