From e520a51df1c65d750798420d5ba1bab4271db264 Mon Sep 17 00:00:00 2001
From: Michael Brown
Date: Fri, 19 Jul 2019 17:35:39 +0100
Subject: [fdt] Add ability to parse a MAC address from a flattened device tree

The Raspberry Pi NIC has no EEPROM to hold the MAC address.  The
platform firmware (e.g. UEFI or U-Boot) will typically obtain the MAC
address from the VideoCore firmware and add it to the device tree,
which is then made available to subsequent programs such as iPXE or
the Linux kernel.

Add the ability to parse a flattened device tree and to extract the
MAC address.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/include/ipxe/errfile.h |   1 +
 src/include/ipxe/fdt.h     | 102 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 103 insertions(+)
 create mode 100644 src/include/ipxe/fdt.h

(limited to 'src/include/ipxe')

diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index 1a92b6ce2..242f91f82 100644
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -74,6 +74,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
 #define ERRFILE_efi_block	       ( ERRFILE_CORE | 0x00220000 )
 #define ERRFILE_sanboot		       ( ERRFILE_CORE | 0x00230000 )
 #define ERRFILE_dummy_sanboot	       ( ERRFILE_CORE | 0x00240000 )
+#define ERRFILE_fdt		       ( ERRFILE_CORE | 0x00250000 )
 
 #define ERRFILE_eisa		     ( ERRFILE_DRIVER | 0x00000000 )
 #define ERRFILE_isa		     ( ERRFILE_DRIVER | 0x00010000 )
diff --git a/src/include/ipxe/fdt.h b/src/include/ipxe/fdt.h
new file mode 100644
index 000000000..97efa100c
--- /dev/null
+++ b/src/include/ipxe/fdt.h
@@ -0,0 +1,102 @@
+#ifndef _IPXE_FDT_H
+#define _IPXE_FDT_H
+
+/** @file
+ *
+ * Flattened Device Tree
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <stdint.h>
+
+struct net_device;
+
+/** Device tree header */
+struct fdt_header {
+	/** Magic signature */
+	uint32_t magic;
+	/** Total size of device tree */
+	uint32_t totalsize;
+	/** Offset to structure block */
+	uint32_t off_dt_struct;
+	/** Offset to strings block */
+	uint32_t off_dt_strings;
+	/** Offset to memory reservation block */
+	uint32_t off_mem_rsvmap;
+	/** Version of this data structure */
+	uint32_t version;
+	/** Lowest version to which this structure is compatible */
+	uint32_t last_comp_version;
+	/** Physical ID of the boot CPU */
+	uint32_t boot_cpuid_phys;
+	/** Length of string block */
+	uint32_t size_dt_strings;
+	/** Length of structure block */
+	uint32_t size_dt_struct;
+} __attribute__ (( packed ));
+
+/** Magic signature */
+#define FDT_MAGIC 0xd00dfeed
+
+/** Expected device tree version */
+#define FDT_VERSION 16
+
+/** Device tree token */
+typedef uint32_t fdt_token_t;
+
+/** Begin node token */
+#define FDT_BEGIN_NODE 0x00000001
+
+/** End node token */
+#define FDT_END_NODE 0x00000002
+
+/** Property token */
+#define FDT_PROP 0x00000003
+
+/** Property fragment */
+struct fdt_prop {
+	/** Data length */
+	uint32_t len;
+	/** Name offset */
+	uint32_t name_off;
+} __attribute__ (( packed ));
+
+/** NOP token */
+#define FDT_NOP 0x00000004
+
+/** End of structure block */
+#define FDT_END 0x00000009
+
+/** Alignment of structure block */
+#define FDT_STRUCTURE_ALIGN ( sizeof ( fdt_token_t ) )
+
+/** A device tree */
+struct fdt {
+	/** Tree data */
+	union {
+		/** Tree header */
+		const struct fdt_header *hdr;
+		/** Raw data */
+		const void *raw;
+	};
+	/** Length of tree */
+	size_t len;
+	/** Offset to structure block */
+	unsigned int structure;
+	/** Length of structure block */
+	size_t structure_len;
+	/** Offset to strings block */
+	unsigned int strings;
+	/** Length of strings block */
+	size_t strings_len;
+};
+
+extern int fdt_path ( const char *path, unsigned int *offset );
+extern int fdt_alias ( const char *name, unsigned int *offset );
+extern const char * fdt_string ( unsigned int offset, const char *name );
+extern int fdt_mac ( unsigned int offset, struct net_device *netdev );
+extern int register_fdt ( const struct fdt_header *hdr );
+
+#endif /* _IPXE_FDT_H */
-- 
cgit v1.2.3-55-g7522