fdt.h

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#ifndef _IPXE_FDT_H
#define _IPXE_FDT_H

/** @file
 *
 * Flattened Device Tree
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
FILE_SECBOOT ( PERMITTED );

#include <stdint.h>
#include <ipxe/image.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 ) )

/** Maximum alignment of any block */
#define FDT_MAX_ALIGN 8

/** A memory reservation */
struct fdt_reservation {
        /** Starting address */
        uint64_t start;
        /** Length of reservation */
        uint64_t size;
} __attribute__ (( packed ));

/** A device tree */
struct fdt {
        /** Tree data */
        union {
                /** Tree header */
                struct fdt_header *hdr;
                /** Raw data */
                void *raw;
        };
        /** Length of tree */
        size_t len;
        /** Used length of tree */
        size_t used;
        /** 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;
        /** Offset to memory reservation block */
        unsigned int reservations;
        /** Reallocate device tree
         *
         * @v fdt               Device tree
         * @v len               New length
         * @ret rc              Return status code
         */
        int ( * realloc ) ( struct fdt *fdt, size_t len );
};

/** A device tree token descriptor */
struct fdt_descriptor {
        /** Offset within structure block */
        unsigned int offset;
        /** Next offset within structure block */
        unsigned int next;
        /** Node or property name (if applicable) */
        const char *name;
        /** Property data (if applicable) */
        const void *data;
        /** Length of property data (if applicable) */
        size_t len;
        /** Depth change */
        int depth;
};

/** A device tree region cell size specification */
struct fdt_reg_cells {
        /** Number of address cells */
        uint32_t address_cells;
        /** Number of size cells */
        uint32_t size_cells;
        /** Number of address cells plus number of size cells */
        unsigned int stride;
};

/** Default number of address cells, if not specified */
#define FDT_DEFAULT_ADDRESS_CELLS 2

/** Default number of size cells, if not specified */
#define FDT_DEFAULT_SIZE_CELLS 1

extern struct image_tag fdt_image __image_tag;
extern struct fdt sysfdt;

/**
 * Get memory reservations
 *
 * @v fdt               Device tree
 * @ret rsv             Memory reservations
 */
static inline const struct fdt_reservation *
fdt_reservations ( struct fdt *fdt ) {

        return ( fdt->raw + fdt->reservations );
}

/** Iterate over memory reservations */
#define for_each_fdt_reservation( rsv, fdt )                    \
        for ( rsv = fdt_reservations ( (fdt) ) ;                \
              ( (rsv)->start || (rsv)->size ) ; rsv++ )

extern int fdt_describe ( struct fdt *fdt, unsigned int offset,
                          struct fdt_descriptor *desc );
extern int fdt_parent ( struct fdt *fdt, unsigned int offset,
                        unsigned int *parent );
extern int fdt_path ( struct fdt *fdt, const char *path,
                      unsigned int *offset );
extern int fdt_alias ( struct fdt *fdt, const char *name,
                       unsigned int *offset );
extern const char * fdt_strings ( struct fdt *fdt, unsigned int offset,
                                  const char *name, unsigned int *count );
extern const char * fdt_string ( struct fdt *fdt, unsigned int offset,
                                 const char *name );
extern int fdt_cells ( struct fdt *fdt, unsigned int offset, const char *name,
                       unsigned int index, unsigned int count,
                       uint64_t *value );
extern int fdt_u64 ( struct fdt *fdt, unsigned int offset, const char *name,
                     uint64_t *value );
extern int fdt_u32 ( struct fdt *fdt, unsigned int offset, const char *name,
                     uint32_t *value );
extern uint32_t fdt_phandle ( struct fdt *fdt, unsigned int offset );
extern void fdt_reg_cells ( struct fdt *fdt, unsigned int offset,
                            struct fdt_reg_cells *regs );
extern int fdt_parent_reg_cells ( struct fdt *fdt, unsigned int offset,
                                  struct fdt_reg_cells *regs );
extern int fdt_reg_count ( struct fdt *fdt, unsigned int offset,
                           struct fdt_reg_cells *regs );
extern int fdt_reg_address ( struct fdt *fdt, unsigned int offset,
                             struct fdt_reg_cells *regs, unsigned int index,
                             uint64_t *address );
extern int fdt_reg_size ( struct fdt *fdt, unsigned int offset,
                          struct fdt_reg_cells *regs, unsigned int index,
                          uint64_t *size );
extern int fdt_reg ( struct fdt *fdt, unsigned int offset, uint64_t *region );
extern int fdt_mac ( struct fdt *fdt, unsigned int offset,
                     struct net_device *netdev );
extern int fdt_parse ( struct fdt *fdt, struct fdt_header *hdr,
                       size_t max_len );
extern int fdt_create ( struct fdt_header **hdr, const char *cmdline,
                        physaddr_t initrd, size_t initrd_len );
extern void fdt_remove ( struct fdt_header *hdr );

#endif /* _IPXE_FDT_H */