1 files changed, 27 insertions, 0 deletions
diff --git a/include/dtb_patch.h b/include/dtb_patch.h
new file mode 100644
index 0000000..7fbe225
--- /dev/null
+++ b/include/dtb_patch.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TB_DTB_PATCH_H
+#define __TB_DTB_PATCH_H
+
+#include <stdint.h>
+
+/*
+ * minimal dtb patcher, no libfdt. walks the flattened devicetree
+ * structure per the devicetree specification (devicetree.dtsi format:
+ * FDT_BEGIN_NODE, name, property, FDT_END_NODE) and rewrites the cpu
+ * nodes for spin table bringup.
+ *
+ * what it does:
+ *   /cpus/cpu@N: enable-method = "spin-table"
+ *                cpu-release-addr = gate address of core N
+ *   /psci: status = "disabled" (so the kernel falls back to the
+ *                    spin table instead of trying hvc)
+ *
+ * properties are rewritten in place where the space fits, the
+ * enable-method string shrinks, cpu-release-addr reuses the space
+ * of an old value. new properties are appended to the last cpu node
+ * by growing the struct block and moving the strings block.
+ */
+
+int tb_dtb_patch_spin_table(uintptr_t dtb, uintptr_t *gates, int ngates);
+
+#endif /* __TB_DTB_PATCH_H */