fit: Add overlay support
This patch adds support to boot FIT image configurations consisting of
a base device tree and one or more overlays. Since extracting the right
compatible string from overlay FDTs is problematic, we'll only support
this for FIT images that have the compatible string pulled out into the
config node.
This patch was adapted from depthcharge's http://crosreview.com/1555293
Change-Id: I0943f9a1869c9e416887c7ff16e33f7d91b74989
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32873
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/include/fit.h b/src/include/fit.h
index 758ee70..1c90aca 100644
--- a/src/include/fit.h
+++ b/src/include/fit.h
@@ -24,8 +24,7 @@
#include <list.h>
#include <program_loading.h>
-struct fit_image_node
-{
+struct fit_image_node {
const char *name;
void *data;
uint32_t size;
@@ -34,11 +33,11 @@
struct list_node list_node;
};
-struct fit_config_node
-{
+struct fit_config_node {
const char *name;
struct fit_image_node *kernel;
struct fit_image_node *fdt;
+ struct list_node overlays;
struct fit_image_node *ramdisk;
struct fdt_property compat;
int compat_rank;
@@ -48,6 +47,11 @@
struct list_node list_node;
};
+struct fit_overlay_chain {
+ struct fit_image_node *overlay;
+ struct list_node list_node;
+};
+
/*
* Updates the cmdline in the devicetree.
*/
diff --git a/src/lib/fit.c b/src/lib/fit.c
index befedde..6ac0a89 100644
--- a/src/lib/fit.c
+++ b/src/lib/fit.c
@@ -96,6 +96,31 @@
return NULL;
}
+static struct fit_image_node *find_image_with_overlays(const char *name,
+ int bytes, struct list_node *prev)
+{
+ struct fit_image_node *base = find_image(name);
+ if (!base)
+ return NULL;
+
+ int len = strnlen(name, bytes) + 1;
+ bytes -= len;
+ name += len;
+ while (bytes > 0) {
+ struct fit_overlay_chain *next = xzalloc(sizeof(*next));
+ next->overlay = find_image(name);
+ if (!next->overlay)
+ return NULL;
+ list_insert_after(&next->list_node, prev);
+ prev = &next->list_node;
+ len = strnlen(name, bytes) + 1;
+ bytes -= len;
+ name += len;
+ }
+
+ return base;
+}
+
static void image_node(struct device_tree_node *node)
{
struct fit_image_node *image = xzalloc(sizeof(*image));
@@ -133,7 +158,8 @@
if (!strcmp("kernel", prop->prop.name))
config->kernel = find_image(prop->prop.data);
else if (!strcmp("fdt", prop->prop.name))
- config->fdt = find_image(prop->prop.data);
+ config->fdt = find_image_with_overlays(prop->prop.data,
+ prop->prop.size, &config->overlays);
else if (!strcmp("ramdisk", prop->prop.name))
config->ramdisk = find_image(prop->prop.data);
else if (!strcmp("compatible", prop->prop.name))
@@ -408,6 +434,14 @@
return -1;
}
+ // FDT overlays are not supported in legacy FIT images.
+ if (config->overlays.next) {
+ printk(BIOS_ERR,
+ "ERROR: config %s has overlay but no compat!\n",
+ config->name);
+ return -1;
+ }
+
if (fdt_find_compat(fdt_blob, fdt_offset, &config->compat)) {
printk(BIOS_ERR,
"ERROR: Can't find compat string in FDT %s "
@@ -442,6 +476,7 @@
struct fit_image_node *image;
struct fit_config_node *config;
struct compat_string_entry *compat_node;
+ struct fit_overlay_chain *overlay_chain;
printk(BIOS_DEBUG, "FIT: Loading FIT from %p\n", fit);
@@ -505,6 +540,8 @@
}
printk(BIOS_DEBUG, ", kernel %s", config->kernel->name);
printk(BIOS_DEBUG, ", fdt %s", config->fdt->name);
+ list_for_each(overlay_chain, config->overlays, list_node)
+ printk(BIOS_DEBUG, " %s", overlay_chain->overlay->name);
if (config->ramdisk)
printk(BIOS_DEBUG, ", ramdisk %s",
config->ramdisk->name);
diff --git a/src/lib/fit_payload.c b/src/lib/fit_payload.c
index b049188..8e75915 100644
--- a/src/lib/fit_payload.c
+++ b/src/lib/fit_payload.c
@@ -206,6 +206,15 @@
return;
}
+ struct fit_overlay_chain *chain;
+ list_for_each(chain, config->overlays, list_node) {
+ struct device_tree *overlay = unpack_fdt(chain->overlay);
+ if (!overlay || dt_apply_overlay(dt, overlay)) {
+ printk(BIOS_ERR, "ERROR: Failed to apply overlay %s!\n",
+ chain->overlay->name);
+ }
+ }
+
dt_apply_fixups(dt);
/* Insert coreboot specific information */