Read the devicetree-overlay property from the blspec entry, set the
firmware search-path based on the blspec root and register a devicetree
overlay when booting the blspec entry.
Signed-off-by: Michael Tretter <m.tretter@xxxxxxxxxxxxxx>
---
Documentation/user/booting-linux.rst | 4 ++++
common/blspec.c | 10 ++++++++
common/bootm.c | 35 ++++++++++++++++++++++++++++
include/bootm.h | 1 +
4 files changed, 50 insertions(+)
diff --git a/Documentation/user/booting-linux.rst b/Documentation/user/booting-linux.rst
index 437f4e80ca..12cd505e71 100644
--- a/Documentation/user/booting-linux.rst
+++ b/Documentation/user/booting-linux.rst
@@ -232,6 +232,10 @@ device where the entry is found on. This makes it possible to use the same rootf
image on different devices without having to specify a different root= option each
time.
+Additionally to the options defined in the original spec, Barebox has the
+``devicetree-overlay`` option. This is a string value that refer to overlays
+that will be applied to the device tree before passing it to Linux.
+
Network boot
------------
diff --git a/common/blspec.c b/common/blspec.c
index 41f2a4c534..d0f2f3b228 100644
--- a/common/blspec.c
+++ b/common/blspec.c
@@ -54,6 +54,7 @@ static int blspec_boot(struct bootentry *be, int verbose, int dryrun)
struct blspec_entry *entry = container_of(be, struct blspec_entry, entry);
int ret;
const char *abspath, *devicetree, *options, *initrd, *linuximage;
+ const char *devicetree_overlay;
const char *appendroot;
struct bootm_data data = {
.initrd_address = UIMAGE_INVALID_ADDRESS,
@@ -69,6 +70,7 @@ static int blspec_boot(struct bootentry *be, int verbose, int dryrun)
initrd = blspec_entry_var_get(entry, "initrd");
options = blspec_entry_var_get(entry, "options");
linuximage = blspec_entry_var_get(entry, "linux");
+ devicetree_overlay = blspec_entry_var_get(entry, "devicetree-overlay");
if (entry->rootpath)
abspath = entry->rootpath;
@@ -88,6 +90,13 @@ static int blspec_boot(struct bootentry *be, int verbose, int dryrun)
}
}
+ if (devicetree_overlay) {
+ data.oftree_overlay_file = basprintf("%s/%s", abspath,
+ devicetree_overlay);
+ setenv("global.firmware.path",
+ basprintf("%s/%s", abspath, "lib/firmware/"));
+ }
+
if (initrd)
data.initrd_file = basprintf("%s/%s", abspath, initrd);
@@ -114,6 +123,7 @@ static int blspec_boot(struct bootentry *be, int verbose, int dryrun)
if (ret)
pr_err("Booting failed\n");
err_out:
+ free((char *)data.oftree_overlay_file);
free((char *)data.oftree_file);
free((char *)data.initrd_file);
free((char *)data.os_file);
diff --git a/common/bootm.c b/common/bootm.c
index 36f6c41bbd..a796e89857 100644
--- a/common/bootm.c
+++ b/common/bootm.c
@@ -499,6 +499,32 @@ static int bootm_open_os_uimage(struct image_data *data)
return 0;
}
+static int bootm_apply_oftree_overlay(const char *path)
+{
+ int ret;
+ struct fdt_header *fdt;
+ struct device_node *root;
+
+ fdt = read_file(path, NULL);
+ if (!fdt) {
+ printf("Unable to read \"%s\"\n", path);
+ return -EINVAL;
+ }
+
+ root = of_unflatten_dtb(fdt);
+ if (IS_ERR(root)) {
+ printf("\"%s\" is not a valid devicetree\n", path);
+ return -EINVAL;
+ }
+
+ ret = of_register_overlay(root);
+ if (ret)
+ pr_warn("Failed to register devicetree overlay \"%s\"\n",
+ path);
+
+ return 0;
+}
+
static void bootm_print_info(struct image_data *data)
{
if (data->os_res)
@@ -631,6 +657,15 @@ int bootm_boot(struct bootm_data *bootm_data)
}
}
+ if (bootm_data->oftree_overlay_file) {
+ ret = bootm_apply_oftree_overlay(bootm_data->oftree_overlay_file);
+ if (ret) {
+ printf("Applying device tree overlay failed with: %s\n",
+ strerror(-ret));
+ ret = 0;
+ }
+ }
+
if (bootm_data->appendroot) {
char *rootarg;
diff --git a/include/bootm.h b/include/bootm.h
index fdc73f711a..d5afd3f018 100644
--- a/include/bootm.h
+++ b/include/bootm.h
@@ -16,6 +16,7 @@ struct bootm_data {
const char *os_file;
const char *initrd_file;
const char *oftree_file;
+ const char *oftree_overlay_file;
int verbose;
enum bootm_verify verify;
bool force;
--
2.20.1
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