[U-Boot] [PATCH v3 3/4] image: fdt: copy possible optee nodes to a loaded devicetree
Heiko Stuebner
heiko at sntech.de
Wed Oct 23 14:46:40 UTC 2019
From: Heiko Stuebner <heiko.stuebner at theobroma-systems.com>
The loading convention for optee or any other tee on arm64 is as bl32
parameter to the trusted-firmware. So TF-A gets invoked with the TEE as
bl32 and main u-boot as bl33. Once it has done its startup TF-A jumps
into the bl32 for the TEE startup, returns to TF-A and then jumps to bl33.
All of them get passed a devicetree as parameter and all components often
get loaded from a FIT image.
OP-TEE will create additional nodes in that devicetree namely a firmware
node and possibly multiple reserved-memory nodes.
While this devicetree is used in main u-boot, in most cases it won't be
the one passed to the actual kernel. Instead most boot commands will load
a new devicetree from somewhere like mass storage of the network, so if
that happens u-boot should transfer the optee nodes to that new devicetree.
To make that happen introduce optee_copy_fdt_nodes() called from the dt
setup function in image-fdt which after checking for the optee presence
in the u-boot dt will make sure a optee node is present in the kernel dt
and transfer any reserved-memory regions it can find.
Signed-off-by: Heiko Stuebner <heiko.stuebner at theobroma-systems.com>
Reviewed-by: Jens Wiklander <jens.wiklander at linaro.org>
---
changes in v2:
- don't create a new optee firmware-node, but instead copy the
compatible+method properties from the old fdt blob.
changes in v3:
- move check for pre-existing optee node into main function
If the kernel-dts already contains optee nodes, we probably
want to leave it _completely_ alone
common/image-fdt.c | 8 +++
include/tee/optee.h | 9 +++
lib/optee/optee.c | 140 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 157 insertions(+)
diff --git a/common/image-fdt.c b/common/image-fdt.c
index 4247dcee0c..48388488d9 100644
--- a/common/image-fdt.c
+++ b/common/image-fdt.c
@@ -17,6 +17,7 @@
#include <linux/libfdt.h>
#include <mapmem.h>
#include <asm/io.h>
+#include <tee/optee.h>
#ifndef CONFIG_SYS_FDT_PAD
#define CONFIG_SYS_FDT_PAD 0x3000
@@ -561,6 +562,13 @@ int image_setup_libfdt(bootm_headers_t *images, void *blob,
}
}
+ fdt_ret = optee_copy_fdt_nodes(gd->fdt_blob, blob);
+ if (fdt_ret) {
+ printf("ERROR: transfer of optee nodes to new fdt failed: %s\n",
+ fdt_strerror(fdt_ret));
+ goto err;
+ }
+
/* Delete the old LMB reservation */
if (lmb)
lmb_free(lmb, (phys_addr_t)(u32)(uintptr_t)blob,
diff --git a/include/tee/optee.h b/include/tee/optee.h
index 9446928fd4..121b30a303 100644
--- a/include/tee/optee.h
+++ b/include/tee/optee.h
@@ -67,4 +67,13 @@ static inline int optee_verify_bootm_image(unsigned long image_addr,
}
#endif
+#if defined(CONFIG_OPTEE) && defined(CONFIG_OF_LIBFDT)
+int optee_copy_fdt_nodes(const void *old_blob, void *new_blob);
+#else
+static inline int optee_copy_fdt_nodes(const void *old_blob, void *new_blob)
+{
+ return 0;
+}
+#endif
+
#endif /* _OPTEE_H */
diff --git a/lib/optee/optee.c b/lib/optee/optee.c
index db92cd9af2..c883c498e1 100644
--- a/lib/optee/optee.c
+++ b/lib/optee/optee.c
@@ -5,6 +5,8 @@
*/
#include <common.h>
+#include <malloc.h>
+#include <linux/libfdt.h>
#include <tee/optee.h>
#define optee_hdr_err_msg \
@@ -63,3 +65,141 @@ error:
return ret;
}
+
+#if defined(CONFIG_OF_LIBFDT)
+static int optee_copy_firmware_node(const void *old_blob, void *fdt_blob)
+{
+ int old_offs, offs, ret, len;
+ const void *prop;
+
+ old_offs = fdt_path_offset(old_blob, "/firmware/optee");
+ if (old_offs < 0) {
+ debug("Original OP-TEE Device Tree node not found");
+ return old_offs;
+ }
+
+ offs = fdt_path_offset(fdt_blob, "/firmware");
+ if (offs < 0) {
+ offs = fdt_path_offset(fdt_blob, "/");
+ if (offs < 0)
+ return offs;
+
+ offs = fdt_add_subnode(fdt_blob, offs, "firmware");
+ if (offs < 0)
+ return offs;
+ }
+
+ offs = fdt_add_subnode(fdt_blob, offs, "optee");
+ if (offs < 0)
+ return ret;
+
+ /* copy the compatible property */
+ prop = fdt_getprop(old_blob, old_offs, "compatible", &len);
+ if (!prop) {
+ debug("missing OP-TEE compatible property");
+ return -EINVAL;
+ }
+
+ ret = fdt_setprop(fdt_blob, offs, "compatible", prop, len);
+ if (ret < 0)
+ return ret;
+
+ /* copy the method property */
+ prop = fdt_getprop(old_blob, old_offs, "method", &len);
+ if (!prop) {
+ debug("missing OP-TEE method property");
+ return -EINVAL;
+ }
+
+ ret = fdt_setprop(fdt_blob, offs, "method", prop, len);
+ if (ret < 0)
+ return ret;
+
+ return 0;
+}
+
+int optee_copy_fdt_nodes(const void *old_blob, void *new_blob)
+{
+ int nodeoffset, subnode, ret;
+ struct fdt_resource res;
+
+ if (fdt_check_header(old_blob))
+ return -EINVAL;
+
+ if (fdt_check_header(new_blob))
+ return -EINVAL;
+
+ /* only proceed if there is an /firmware/optee node */
+ if (fdt_path_offset(old_blob, "/firmware/optee") < 0) {
+ debug("No OP-TEE firmware node in old fdt, nothing to do");
+ return 0;
+ }
+
+ /*
+ * Do not proceed if the target dt already has an OP-TEE node.
+ * In this case assume that the system knows better somehow,
+ * so do not interfere.
+ */
+ if (fdt_path_offset(new_blob, "/firmware/optee") >= 0) {
+ debug("OP-TEE Device Tree node already exists in target");
+ return 0;
+ }
+
+ ret = optee_copy_firmware_node(old_blob, new_blob);
+ if (ret < 0) {
+ printf("Failed to add OP-TEE firmware node\n");
+ return ret;
+ }
+
+ /* optee inserts its memory regions as reserved-memory nodes */
+ nodeoffset = fdt_subnode_offset(old_blob, 0, "reserved-memory");
+ if (nodeoffset >= 0) {
+ subnode = fdt_first_subnode(old_blob, nodeoffset);
+ while (subnode >= 0) {
+ const char *name = fdt_get_name(old_blob,
+ subnode, NULL);
+ if (!name)
+ return -EINVAL;
+
+ /* only handle optee reservations */
+ if (strncmp(name, "optee", 5))
+ continue;
+
+ /* check if this subnode has a reg property */
+ ret = fdt_get_resource(old_blob, subnode, "reg", 0,
+ &res);
+ if (!ret) {
+ struct fdt_memory carveout = {
+ .start = res.start,
+ .end = res.end,
+ };
+ char *oldname, *nodename, *tmp;
+
+ oldname = strdup(name);
+ if (!oldname)
+ return -ENOMEM;
+
+ tmp = oldname;
+ nodename = strsep(&tmp, "@");
+ if (!nodename) {
+ free(oldname);
+ return -EINVAL;
+ }
+
+ ret = fdtdec_add_reserved_memory(new_blob,
+ nodename,
+ &carveout,
+ NULL);
+ free(oldname);
+
+ if (ret < 0)
+ return ret;
+ }
+
+ subnode = fdt_next_subnode(old_blob, subnode);
+ }
+ }
+
+ return 0;
+}
+#endif
--
2.23.0
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