bsps/shared/ofw: Implement RTEMS OFW interface

RTEMS OFW is a FDT only implementation of the OpenFirmWare
interface. This API is created to be compatible with FreeBSD
OpenFirmWare interface. The main intention is to make
porting of FreeBSD drivers to RTEMS easier.

Most functions implemented have an direct one-one mapping
with the original OFW API and some extra auxiliary functions
were implemented to make working with device trees easier in
RTEMS.

Update #3784

5 files changed, 1353 insertions, 0 deletions

diff --git a/bsps/include/ofw/ofw.h b/bsps/include/ofw/ofw.h
new file mode 100644
index 0000000000..411010be89
--- /dev/null
+++ b/bsps/include/ofw/ofw.h
@@ -0,0 +1,548 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup ofw
+ *
+ * RTEMS FDT implementation of OpenFirmWare Interface.
+ *
+ * RTEMS OFW is a FDT only implementation of the OpenFirmWare interface.
+ * This API is created to be compatible with FreeBSD OpenFirmWare interface.
+ * The main intention is to make porting of FreeBSD drivers to RTEMS easier.
+ */
+
+/*
+ * Copyright (C) 2020 Niteesh Babu G S <niteesh.gs@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _OFW_H
+#define _OFW_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <rtems.h>
+#include <stdint.h>
+#include <sys/types.h>
+
+/**
+ * Represents a node in the device tree. The offset from fdtp to node is used
+ * instead of fdt offset to make sure this is compatible with OF interface in
+ * FreeBSD.
+ */
+typedef uint32_t  phandle_t;
+/**
+ * Represents the effective phandle of the node.
+ */
+typedef uint32_t  ihandle_t;
+/**
+ * Represents the data type of the buffer.
+ */
+typedef uint32_t  pcell_t;
+
+/**
+ * @struct rtems_ofw_memory_area
+ *
+ * This is used to represent elements(FDT properties) that define
+ * region of memory address.
+ */
+typedef struct {
+  /** The start address of the memory region. */
+  uint32_t start;
+  /** The size of the memory region. */
+  uint32_t size;
+} rtems_ofw_memory_area;
+
+/**
+ * @struct rtems_ofw_ranges
+ *
+ * This is used to represent the ranges property in the device tree.
+ */
+typedef struct {
+  /** The physical address within the child bus address space */
+  uint32_t child_bus;
+  /** The physical address within the parent bus address space */
+  uint32_t parent_bus;
+  /** The size of the range in the child’s address space */
+  uint32_t size;
+} rtems_ofw_ranges;
+
+/**
+ * @brief Gets the node that is next to @a node.
+ *
+ * @param[in] node Node offset
+ *
+ * @retval Peer node offset Successful operation.
+ * @retval 0 No peer node or invalid node handle
+ */
+phandle_t rtems_ofw_peer(
+  phandle_t   node
+);
+
+/**
+ * @brief Gets the node that is the child of @a node.
+ *
+ * @param[in] node Node offset
+ *
+ * @retval child node offset Successful operation.
+ * @retval 0 No child node or invalid node handle
+ */
+phandle_t rtems_ofw_child(
+  phandle_t   node
+);
+
+/**
+ * @brief Gets the node that is the parent of @a node.
+ *
+ * @param[in] node Node offset
+ *
+ * @retval child node offset Successful operation.
+ * @retval 0 No child node or invalid node handle
+ */
+phandle_t rtems_ofw_parent(
+  phandle_t   node
+);
+
+/**
+ * @brief Gets the length of the property mentioned in @a propname.
+ *
+ * @param[in] node Node offset
+ * @param[in] prop Property name
+ *
+ * @retval -1 Invalid node or property
+ * @retval  Length of property on successful operation
+ */
+ssize_t rtems_ofw_get_prop_len(
+  phandle_t   node,
+  const char *propname
+);
+
+/**
+ * @brief Gets the value of property mentioned in @a propname.
+ *
+ * @param[in] node Node offset
+ * @param[in] prop Property name
+ * @param[out] buf The property value gets stored in this buffer (Pre-allocated)
+ * @param[in] len Length of the buffer
+ 
+ * @retval -1 Invalid node or property
+ * @retval  Length of property on successful operation
+ */
+ssize_t rtems_ofw_get_prop(
+  phandle_t    node,
+  const char  *propname,
+  void        *buf,
+  size_t       len
+);
+
+/**
+ * @brief Gets the value of property mentioned in @a prop.
+ * 
+ * Gets the value of property of @a node and converts the value into the host's
+ * endianness.
+ *
+ * @param[in] node Node offset
+ * @param[in] prop Property name
+ * @param[out] buf The property value gets stored in this buffer(Pre-allocated)
+ * after converted to the host's endianness
+ * @param[in] len Length of the buffer
+ *
+ * @retval -1 Invalid node or property
+ * @retval  Length of property on successful operation
+ */
+ssize_t rtems_ofw_get_enc_prop(
+  phandle_t    node,
+  const char  *prop,
+  pcell_t     *buf,
+  size_t       len
+);
+
+/**
+ * @brief Checks if the property @a propname is present in @a node.
+ *
+ * @param[in] node Node offset
+ * @param[in] propname Property name
+ *
+ *  @retval  0 Property not present.
+ *  @retval  1 Property is present.
+ */
+int rtems_ofw_has_prop(
+  phandle_t    node,
+  const char  *propname
+);
+
+/**
+ * @brief Searches for property @a propname in @a node.
+ * 
+ * Searches the node and its parent recursively for the property and fills the
+ * buffer with the first found value.
+ *
+ * @param[in] node Node offset
+ * @param[in] propname Property name
+ * @param[out] buf The property value gets stored in this buffer (Pre-allocated)
+ * @param[in] len Length of the buffer
+ *
+ * @retval  Length of the property if property is found.
+ * @retval  -1 Property is not found.
+ */
+ssize_t rtems_ofw_search_prop(
+  phandle_t    node,
+  const char  *propname,
+  void        *buf,
+  size_t       len
+);
+
+/**
+ * @brief Searches for property @a propname in @a node.
+ * 
+ * Searches the node and its parent recursively for the property and fills the 
+ * buffer with the first value found after converting it to the endianness of
+ * the host.
+ *
+ * @param[in] node Node offset
+ * @param[in] propname Property name
+ * @param[out] buf The property value gets stored in this buffer(Pre-allocated)
+ * after converted to the host's endianness
+ * @param[in] len Length of the buffer
+ *
+ * @retval  Length of the property if property is found.
+ * @retval  -1 Property is not found.
+ */
+ssize_t rtems_ofw_search_enc_prop(
+  phandle_t    node,
+  const char  *propname,
+  pcell_t     *buf,
+  size_t       len
+);
+
+/**
+ * @brief Gets the value of property mentioned in @a propname.
+ *
+ * Same as rtems_ofw_getprop, but the @a buf is allocated in this routine and
+ * the user is responsible for freeing it.
+ * 
+ * @param[in] node Node offset
+ * @param[in] propname Property name
+ * @param[out] buf The buffer is allocated in this routine and user is
+ * responsible for freeing.
+ *
+ * @retval  -1 Property is not found.
+ * @retval  Length of the property if property is found.
+ */
+ssize_t rtems_ofw_get_prop_alloc(
+  phandle_t    node,
+  const char  *propname,
+  void       **buf
+);
+
+/**
+ * @brief Gets multiple values of the property @a propname.
+ * 
+ * Same as rtems_ofw_getprop_alloc but it can read properties with multiple
+ * values.
+ * For eg: reg = <0x1000 0x10 0x2000 0x20>
+ *
+ * @param[in] node Node offset
+ * @param[in] propname Property name
+ * @param[in] elsz Size of the single value
+ * @param[out] buf The buffer is allocated in this routine and user is
+ * responsible for freeing.
+ *
+ * @retval  -1 Property is not found.
+ * @retval   Number of values read.
+ */
+ssize_t rtems_ofw_get_prop_alloc_multi(
+  phandle_t    node,
+  const char  *propname,
+  int          elsz,
+  void       **buf
+);
+
+/**
+ * @brief Gets the value of property mentioned in @a propname.
+ * 
+ * Same as rtems_ofw_getprop_alloc but the value stored in the buffer is
+ * converted into the host's endianness.
+ *
+ * @param[in] node Node offset
+ * @param[in] propname Property name
+ * @param[out] buf The buffer is allocated in this routine and user is
+ * responsible for freeing.
+ *
+ * @retval  -1 Property is not found.
+ * @retval  Length of the property if property is found.
+ */
+ssize_t rtems_ofw_get_enc_prop_alloc(
+  phandle_t    node,
+  const char  *propname,
+  void       **buf
+);
+
+/**
+ * @brief Gets multiple values of the property @a propname.
+ *
+ * Same as rtems_ofw_getprop_alloc_multi but the values stored in the buffer
+ * are converted to the host's endianness.
+ * 
+ * @param[in] node Node offset
+ * @param[in] propname Property name
+ * @param[in] elsz Size of the single value
+ * @param[out] buf The buffer is allocated in this routine and user is
+ * responsible for freeing.
+ *
+ * @retval  -1 Property is not found.
+ * @retval   Number of values read.
+ */
+ssize_t rtems_ofw_get_enc_prop_alloc_multi(
+  phandle_t     node,
+  const char   *propname,
+  int           elsz,
+  void        **buf
+);
+
+/**
+ * @brief Free's the buffers allocated by the rtems_ofw_*_alloc functions.
+ *
+ * @param[in] buf Buffer to be freed
+ */
+void rtems_ofw_free(
+  void   *buf
+);
+
+/**
+ * @brief Finds the next property of @a node.
+ * 
+ * Finds the next property of the node and when @a propname is NULL it returns
+ * the value in the first property.
+ *
+ * @param[in] node Node offset
+ * @param[in] previous Previous property name
+ * @param[out] buf The value of the next property gets stored in this buffer
+ * (Pre-allocated)
+ * @param[in] len Length of the buffer
+ *
+ * @retval  -1 node or previous property does not exist
+ * @retval   0 no more properties
+ * @retval   1 success
+ */
+int rtems_ofw_next_prop(
+  phandle_t    node,
+  const char  *previous,
+  char        *buf,
+  size_t       len
+);
+
+/**
+ * @brief Sets the property @name of @a node to @a buf.
+ *
+ * @param[in] node Node offset
+ * @param[in] name Property name
+ * @param[in] buf Buffer contains the value to be set.
+ * @param[in] len Length of the buffer
+ *
+ * @retval  -1 node does not exist
+ * @retval   0 on success
+ * @retval   libFDT error codes on unsuccessful setting operation
+ */
+int rtems_ofw_set_prop(
+  phandle_t    node,
+  const char  *name,
+  const void  *buf,
+  size_t       len
+);
+
+/**
+ * @brief Converts a device specifier to a fully qualified path name.
+ *
+ * @param[in] dev device specifier
+ * @param[out] buf The path is filled into the buffer(Pre-allocated)
+ * @param[in] length of the buffer
+ *
+ * @retval  -1 always. Unimplemented.
+ */
+ssize_t rtems_ofw_canon(
+  const char  *dev,
+  char        *buf,
+  size_t       len
+);
+
+/**
+ * @brief Finds the node at the given path
+ *
+ * @param[in] path to the node from root
+ *
+ * @retval  -1 node does not exist
+ * @retval   node handle on success
+ */
+phandle_t rtems_ofw_find_device(
+  const char  *path
+);
+
+/**
+ * @brief This routine converts effective phandle @a xref to node offset.
+ *
+ * @param[in] xref Node phandle
+ *
+ * @retval Node offset on success
+ * @retval Node phandle on failure
+ */
+phandle_t rtems_ofw_node_from_xref(
+  phandle_t   xref
+);
+
+/**
+ * @brief This routine converts node offset to effective phandle of @a node.
+ *
+ * @retval Node phandle on success
+ * @retval Node offset on failure
+ */
+phandle_t rtems_ofw_xref_from_node(
+  phandle_t   node
+);
+
+/*
+ * instance handles(ihandle_t) as same as phandles in the FDT implementation
+ * of OF interface.
+ */
+
+/**
+ * @brief Converts @a instance handle to phandle.
+ *
+ * instance are same as node offsets in FDT.
+ * 
+ * @param[in] instance Node offset
+ * 
+ * @retval phandle of node on success.
+ * @retval instance of node on failure.
+ */
+phandle_t rtems_ofw_instance_to_package(
+  ihandle_t   instance
+);
+
+/**
+ * @brief Find the node's path from phandle.
+ * 
+ * @param[in] node Node offset
+ * @param[out] buf Path is filled into this buffer(Pre-allocated).
+ * @param[in] len Length of the buffer.
+ *
+ * @retval -1 always. Unimplemented.
+ */
+ssize_t rtems_ofw_package_to_path(
+  phandle_t   node,
+  char       *buf,
+  size_t      len
+);
+
+/**
+ * @brief Find the node's path from ihandle.
+ * 
+ * @param[in] instance Node offset
+ * @param[out] buf Path is filled into this buffer(Pre-allocated).
+ * @param[in] len Length of the buffer.
+ *
+ * @retval -1 always. Unimplemented.
+ */
+ssize_t rtems_ofw_instance_to_path(
+  ihandle_t  instance,
+  char      *buf,
+  size_t     len
+);
+
+/**
+ * @brief Queries the node's reg value.
+ *
+ * This routine fills the buffer @a buf with the values in reg property of node
+ * @a node. It reads all the values of the property and fills the buffer to max
+ * size.
+ * This routine is local to RTEMS OFW and does not have an corresponding
+ * FreeBSD OFW pair.
+ *
+ * @param[in] node Node offset
+ * @param[out] buf Register values are stored in this buffer(Pre-allocated).
+ * @param[in] size Length of the buffer.
+ *
+ * @retval -1 If reg property is missing.
+ * @retval  Length of the reg property in bytes.
+ */
+int rtems_ofw_get_reg(
+  phandle_t              node,
+  rtems_ofw_memory_area *buf,
+  size_t                 size
+);
+
+/**
+ * @brief Queries the node's interrupt value.
+ *
+ * This routine fills the buffer @a buf with the interrupt number. In case of
+ * multiple numbers it fills the buffer to its full extent.
+ * This routine is local to RTEMS OFW and does not have an corresponding
+ * FreeBSD OFW pair.
+ *
+ * @param[in] node Node offset
+ * @param[out] buf Interrupt values are stored in this buffer(Pre-allocated).
+ * @param[in] size Length of the buffer.
+ *
+ * @retval -1 If interrupts property is missing.
+ * @retval  The number of interrupt numbers read.
+ */
+int rtems_ofw_get_interrupts(
+  phandle_t            node,
+  rtems_vector_number *buf,
+  size_t               size
+);
+
+/**
+ * @brief Queries the node's status.
+ *
+ * This routine is local to RTEMS OFW and does not have an corresponding
+ * FreeBSD OFW pair.
+ *
+ * @param[in] node Node offset
+ *
+ * @retval true  Status is OK or empty.
+ * @retval false Status is not OK or missing.
+ */
+bool rtems_ofw_node_status( phandle_t node );
+
+/**
+ * @brief Gets node phandle from compatible property.
+ *
+ * This routine is local to RTEMS OFW and does not have an corresponding
+ * FreeBSD OFW pair.
+ *
+ * @param[in] compat Compatible string
+ *
+ * @retval 0 Node with @a compat as compatible string not found
+ * @retval Node phandle on success.
+ */
+phandle_t rtems_ofw_find_device_by_compat( const char *compat );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _OFW_H */
diff --git a/bsps/include/ofw/ofw_compat.h b/bsps/include/ofw/ofw_compat.h
new file mode 100644
index 0000000000..be4a5ea3ce
--- /dev/null
+++ b/bsps/include/ofw/ofw_compat.h
@@ -0,0 +1,74 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup ofw
+ *
+ * This file defines necessary symbols to make the RTEMS OFW API compatible
+ * with FreeBSD OFW.
+ */
+
+/*
+ * Copyright (C) 2020 Niteesh Babu G S <niteesh.gs@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _OFW_COMPAT_H
+#define _OFW_COMPAT_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <ofw/ofw.h>
+
+#define OF_peer                   rtems_ofw_peer
+#define OF_child                  rtems_ofw_child
+#define OF_parent                 rtems_ofw_parent
+#define OF_getproplen             rtems_ofw_get_prop_len
+#define OF_getprop                rtems_ofw_get_prop
+#define OF_getencprop             rtems_ofw_get_enc_prop
+#define OF_hasprop                rtems_ofw_has_prop
+#define OF_searchprop             rtems_ofw_search_prop
+#define OF_searchencprop          rtems_ofw_search_enc_prop
+#define OF_getprop_alloc          rtems_ofw_get_prop_alloc
+#define OF_getprop_alloc_multi    rtems_ofw_get_prop_alloc_multi
+#define OF_getencprop_alloc_multi rtems_ofw_get_enc_prop_alloc_multi
+#define OF_getencprop_alloc       rtems_ofw_get_enc_prop_alloc
+#define OF_prop_free              rtems_ofw_free
+#define OF_nextprop               rtems_ofw_next_prop
+#define OF_setprop                rtems_ofw_set_prop
+#define OF_canon                  rtems_ofw_canon
+#define OF_finddevice             rtems_ofw_find_device
+#define OF_package_to_path        rtems_ofw_package_to_path
+#define OF_node_from_xref         rtems_ofw_node_from_xref
+#define OF_xref_from_node         rtems_ofw_xref_from_node
+#define OF_instance_to_package    rtems_ofw_instance_to_package
+#define OF_instance_to_path       rtems_ofw_instance_to_path
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _OFW_COMPAT_H */
diff --git a/bsps/include/ofw/ofw_test.h b/bsps/include/ofw/ofw_test.h
new file mode 100644
index 0000000000..a2f3a5c5bf
--- /dev/null
+++ b/bsps/include/ofw/ofw_test.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup ofw
+ *
+ * RTEMS OFW test interface.
+ *
+ * This header must be included only for testing purposes.
+ */
+
+/*
+ * Copyright (C) 2020 Niteesh Babu G S <niteesh.gs@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+
+/**
+ * @brief Initialize the OFW API with the device tree blob.
+ * This function should only be invoked for testing purposes.
+ */
+void rtems_ofw_init( void );
\ No newline at end of file
diff --git a/bsps/shared/ofw/ofw.c b/bsps/shared/ofw/ofw.c
new file mode 100644
index 0000000000..82924b2600
--- /dev/null
+++ b/bsps/shared/ofw/ofw.c
@@ -0,0 +1,683 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+
+/**
+ * @file
+ *
+ * @ingroup ofw
+ */
+
+/*
+ * Copyright (C) 2020 Niteesh Babu G S <niteesh.gs@gmail.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <bsp/fdt.h>
+#include <sys/param.h>
+#include <ofw/ofw.h>
+#include <libfdt.h>
+#include <assert.h>
+#include <rtems/sysinit.h>
+#include <ofw/ofw_test.h>
+
+static void *fdtp = NULL;
+
+static phandle_t rtems_fdt_offset_to_phandle( int offset )
+{
+  if (offset < 0) {
+    return 0;
+  }
+
+  return (phandle_t)offset + fdt_off_dt_struct(fdtp);
+}
+
+static int rtems_fdt_phandle_to_offset( phandle_t handle )
+{
+  int off;
+  int fdt_off;
+
+  off = (int) handle;
+  fdt_off = fdt_off_dt_struct(fdtp);
+
+  if (off < fdt_off) {
+    return -1;
+
+  }
+
+  return off - fdt_off;
+}
+
+void rtems_ofw_init( void ) {
+  int rv;
+  const void *fdt;
+  
+  fdt = bsp_fdt_get();
+
+  rv = fdt_check_header(fdt);
+
+  /*
+   * If the FDT is invalid exit through fatal.
+   */
+  if (rv != 0) {
+    rtems_fatal_error_occurred(RTEMS_NOT_CONFIGURED);
+  }
+
+  fdtp = (void *)fdt;
+}
+
+RTEMS_SYSINIT_ITEM(
+  rtems_ofw_init,
+  RTEMS_SYSINIT_BSP_PRE_DRIVERS,
+  RTEMS_SYSINIT_ORDER_FIRST
+);
+
+phandle_t rtems_ofw_peer( phandle_t node )
+{
+  int offset;
+
+  if (node == 0) {
+    int root = fdt_path_offset(fdtp, "/");
+    return rtems_fdt_offset_to_phandle(root);
+  }
+
+  offset = rtems_fdt_phandle_to_offset(node);
+  if (offset < 0) {
+    return 0;
+  }
+
+  offset = fdt_next_subnode(fdtp, offset);
+  return rtems_fdt_offset_to_phandle(offset);
+}
+
+phandle_t rtems_ofw_child( phandle_t node )
+{
+  int offset;
+
+  offset = rtems_fdt_phandle_to_offset(node);
+
+  if (offset < 0) {
+    return 0;
+  }
+
+  offset = fdt_first_subnode(fdtp, offset);
+  return rtems_fdt_offset_to_phandle(offset);
+}
+
+phandle_t rtems_ofw_parent( phandle_t node )
+{
+  int offset;
+
+  offset = rtems_fdt_phandle_to_offset(node);
+
+  if (offset < 0) {
+    return 0;
+  }
+
+  offset = fdt_parent_offset(fdtp, offset);
+  return rtems_fdt_offset_to_phandle(offset);
+}
+
+ssize_t rtems_ofw_get_prop_len(
+  phandle_t node,
+  const char *propname
+)
+{
+  int offset;
+  int len;
+  const void *prop;
+
+  offset = rtems_fdt_phandle_to_offset(node);
+
+  if (offset < 0) {
+    return -1;
+  }
+
+  prop = fdt_getprop(fdtp, offset, propname, &len);
+
+  if (prop == NULL && strcmp(propname, "name") == 0) {
+    fdt_get_name(fdtp, offset, &len);
+    return len + 1;
+  }
+
+  if (prop == NULL && strcmp(propname, "/chosen") == 0) {
+    if (strcmp(propname, "fdtbootcpu") == 0)
+      return sizeof(pcell_t);
+    if (strcmp(propname, "fdtmemreserv") == 0)
+      return 2 * sizeof(uint64_t) * fdt_num_mem_rsv(fdtp);
+  }
+
+  if (prop == NULL) {
+    return -1;
+  }
+
+  return len;
+}
+
+ssize_t rtems_ofw_get_prop(
+  phandle_t    node,
+  const char  *propname,
+  void        *buf,
+  size_t       bufsize
+)
+{
+  const void *prop;
+  int offset;
+  int len;
+  uint32_t cpuid;
+
+  offset = rtems_fdt_phandle_to_offset(node);
+
+  if (offset < 0) {
+    return -1;
+  }
+
+  prop = fdt_getprop(fdtp, offset, propname, &len);
+
+  if (prop == NULL && strcmp(propname, "name") == 0) {
+    prop = fdt_get_name(fdtp, offset, &len);
+    strncpy(buf, prop, bufsize);
+    return len + 1;
+  }
+
+  if (prop == NULL && strcmp(propname, "/chosen") == 0) {
+    if (strcmp(propname, "fdtbootcpu") == 0) {
+      cpuid = cpu_to_fdt32(fdt_boot_cpuid_phys(fdtp));
+      len = sizeof(cpuid);
+      prop = &cpuid;
+    }
+    if (strcmp(propname, "fdtmemreserv") == 0) {
+      prop = (char *)fdtp + fdt_off_mem_rsvmap(fdtp);
+      len = sizeof(uint64_t)*2*fdt_num_mem_rsv(fdtp);
+    }
+  }
+
+  if (prop == NULL) {
+    return -1;
+  }
+
+  bcopy(prop, buf, MIN(len, bufsize));
+
+  return len;
+}
+
+ssize_t rtems_ofw_get_enc_prop(
+  phandle_t    node,
+  const char  *prop,
+  pcell_t     *buf,
+  size_t       len
+)
+{
+  ssize_t rv;
+
+  assert(len % 4 == 0);
+  rv = rtems_ofw_get_prop(node, prop, buf, len);
+
+  if (rv < 0) {
+    return rv;
+  }
+
+  for (int i = 0; i < (len / 4); i++) {
+    buf[i] = fdt32_to_cpu(buf[i]);
+  }
+
+  return rv;
+}
+
+int rtems_ofw_has_prop(
+  phandle_t    node,
+  const char  *propname
+)
+{
+  ssize_t rv;
+
+  rv = rtems_ofw_get_prop_len(node, propname);
+  return rv >= 0 ? 1 : 0;
+}
+
+ssize_t rtems_ofw_search_prop(
+  phandle_t    node,
+  const char  *propname,
+  void        *buf,
+  size_t       len
+)
+{
+  ssize_t rv;
+
+  for (; node != 0; node = rtems_ofw_parent(node)) {
+    if ((rv = rtems_ofw_get_prop(node, propname, buf, len) != -1)) {
+      return rv;
+    }
+  }
+
+  return -1;
+}
+
+ssize_t rtems_ofw_search_enc_prop(
+  phandle_t    node,
+  const char  *propname,
+  pcell_t     *buf,
+  size_t       len
+)
+{
+  ssize_t rv;
+
+  for (; node != 0; node = rtems_ofw_parent(node)) {
+    if ((rv = rtems_ofw_get_enc_prop(node, propname, buf, len) != -1)) {
+      return rv;
+    }
+  }
+
+  return -1;
+}
+
+ssize_t rtems_ofw_get_prop_alloc(
+  phandle_t    node,
+  const char  *propname,
+  void       **buf
+)
+{
+  ssize_t len;
+
+  *buf = NULL;
+  if ((len = rtems_ofw_get_prop_len(node, propname)) == -1) {
+    return -1;
+  }
+
+  if (len > 0) {
+    *buf = malloc(len);
+    if (*buf == NULL) {
+      return -1;
+    }
+
+    if (rtems_ofw_get_prop(node, propname, *buf, len) == -1) {
+      rtems_ofw_free(buf);
+      *buf = NULL;
+      return -1;
+    }
+  }
+
+  return len;
+}
+
+ssize_t rtems_ofw_get_prop_alloc_multi(
+  phandle_t    node,
+  const char  *propname,
+  int          elsz,
+  void       **buf
+)
+{
+  ssize_t len;
+
+  *buf = NULL;
+  if ((len = rtems_ofw_get_prop_len(node, propname)) == -1 ||
+      (len % elsz != 0)) {
+    return -1;
+  }
+
+  if (len > 0) {
+    *buf = malloc(len);
+    if (*buf == NULL) {
+      return -1;
+    }
+
+    if (rtems_ofw_get_prop(node, propname, *buf, len) == -1) {
+      rtems_ofw_free(buf);
+      *buf = NULL;
+      return -1;
+    }
+  }
+
+  return (len / elsz);
+}
+
+ssize_t rtems_ofw_get_enc_prop_alloc(
+  phandle_t    node,
+  const char  *propname,
+  void       **buf
+)
+{
+  ssize_t len;
+
+  *buf = NULL;
+  if ((len = rtems_ofw_get_prop_len(node, propname)) == -1) {
+    return -1;
+  }
+
+  if (len > 0) {
+    *buf = malloc(len);
+    if (*buf == NULL) {
+      return -1;
+    }
+
+    if (rtems_ofw_get_enc_prop(node, propname, *buf, len) == -1) {
+      rtems_ofw_free(buf);
+      *buf = NULL;
+      return -1;
+    }
+  }
+
+  return len;
+}
+
+ssize_t rtems_ofw_get_enc_prop_alloc_multi(
+  phandle_t     node,
+  const char   *propname,
+  int           elsz,
+  void        **buf
+)
+{
+  ssize_t len;
+
+  *buf = NULL;
+  if ((len = rtems_ofw_get_prop_len(node, propname)) == -1 ||
+      (len % elsz != 0)) {
+    return -1;
+  }
+
+  if (len > 0) {
+    *buf = malloc(len);
+    if (*buf == NULL) {
+      return -1;
+    }
+
+    if (rtems_ofw_get_enc_prop(node, propname, *buf, len) == -1) {
+      rtems_ofw_free(buf);
+      *buf = NULL;
+      return -1;
+    }
+  }
+
+  return (len / elsz);
+}
+
+void rtems_ofw_free( void *buf )
+{
+  free(buf);
+}
+
+int rtems_ofw_next_prop(
+  phandle_t    node,
+  const char  *previous,
+  char        *buf,
+  size_t       len
+)
+{
+  const void *name;
+  const void *prop;
+  int offset;
+
+  offset = rtems_fdt_phandle_to_offset(node);
+
+  if (offset < 0) {
+    return -1;
+  }
+
+  if (previous == NULL) {
+    offset = fdt_first_property_offset(fdtp, offset);
+  } else {
+    fdt_for_each_property_offset(offset, fdtp, offset) {
+      prop = fdt_getprop_by_offset(fdtp, offset, (const char **)&name, NULL);
+      if (prop == NULL)
+        return -1;
+
+      if (strcmp(previous, name) != 0)
+        continue;
+
+      offset = fdt_next_property_offset(fdtp, offset);
+      break;
+    }
+  }
+
+  if (offset < 0)
+    return 0;
+
+  prop = fdt_getprop_by_offset(fdtp, offset, (const char **)&name, &offset);
+  if (prop == NULL)
+    return -1;
+
+  strncpy(buf, name, len);
+
+  return 1;
+}
+
+int rtems_ofw_set_prop(
+  phandle_t    node,
+  const char  *name,
+  const void  *buf,
+  size_t       len
+)
+{
+  int offset;
+
+  offset = rtems_fdt_phandle_to_offset(node);
+
+  if (offset < 0)
+    return -1;
+
+  if (fdt_setprop_inplace(fdtp, offset, name, buf, len) != 0)
+    return (fdt_setprop(fdtp, offset, name, buf, len));
+
+  return 0;
+}
+
+phandle_t rtems_ofw_find_device( const char *path )
+{
+  int offset;
+
+  offset = fdt_path_offset(fdtp, path);
+  if (offset < 0)
+    return -1;
+
+  return rtems_fdt_offset_to_phandle(offset);
+}
+
+static phandle_t rtems_ofw_get_effective_phandle(
+  phandle_t node,
+  phandle_t xref
+)
+{
+  phandle_t child;
+  phandle_t ref;
+
+  for (child = rtems_ofw_child(node); child != 0; child = rtems_ofw_peer(child)) {
+    ref = rtems_ofw_get_effective_phandle(child, xref);
+    if (ref != -1)
+      return ref;
+
+    if (rtems_ofw_get_enc_prop(child, "phandle", &ref, sizeof(ref)) == -1 &&
+        rtems_ofw_get_enc_prop(child, "ibm,phandle", &ref, sizeof(ref)) == -1 &&
+        rtems_ofw_get_enc_prop(child, "linux,phandle", &ref, sizeof(ref)) == -1
+    ) {
+      continue;
+    }
+
+    if (ref == xref)
+      return child;
+  }
+
+  return -1;
+}
+
+phandle_t rtems_ofw_node_from_xref( phandle_t xref )
+{
+  phandle_t node;
+
+  if ((node = rtems_ofw_get_effective_phandle(rtems_ofw_peer(0), xref)) == -1)
+    return xref;
+
+  return node;
+}
+
+phandle_t rtems_ofw_xref_from_node( phandle_t node )
+{
+  phandle_t ref;
+
+    if (rtems_ofw_get_enc_prop(node, "phandle", &ref, sizeof(ref)) == -1 &&
+        rtems_ofw_get_enc_prop(node, "ibm,phandle", &ref, sizeof(ref)) == -1 &&
+        rtems_ofw_get_enc_prop(node, "linux,phandle", &ref, sizeof(ref)) == -1)
+    {
+      return node;
+    }
+
+    return ref;
+}
+
+phandle_t rtems_ofw_instance_to_package( ihandle_t instance )
+{
+  return rtems_ofw_node_from_xref(instance);
+}
+
+ssize_t rtems_ofw_package_to_path(
+  phandle_t   node,
+  char       *buf,
+  size_t      len
+)
+{
+  int offset;
+  int rv;
+
+  offset = rtems_fdt_phandle_to_offset(node);
+
+  rv = fdt_get_path(fdtp, offset, buf, len);
+  if (rv != 0)
+    return -1;
+
+  return rv;
+}
+
+ssize_t rtems_ofw_instance_to_path(
+  ihandle_t  instance,
+  char      *buf,
+  size_t     len
+)
+{
+  int offset;
+  int rv;
+
+  offset = rtems_ofw_instance_to_package(instance);
+  offset = rtems_fdt_phandle_to_offset(offset);
+
+  rv = fdt_get_path(fdtp, offset, buf, len);
+  if (rv != 0)
+    return -1;
+
+  return rv;
+}
+
+int rtems_ofw_get_reg(
+  phandle_t              node,
+  rtems_ofw_memory_area *buf,
+  size_t                 size
+)
+{
+  int len;
+  int offset;
+  int nranges;
+  int nregs;
+  phandle_t parent;
+  rtems_ofw_ranges range;
+  const rtems_ofw_ranges *ptr;
+
+  len = rtems_ofw_get_enc_prop(node, "reg", (pcell_t *)buf, size);
+  if (len <= 0) {
+    return len;
+  }
+
+  nregs = MIN(len, size) / sizeof(rtems_ofw_memory_area);
+
+  for (parent = rtems_ofw_parent(node); parent > 0;
+      parent = rtems_ofw_parent(parent)) {
+
+    offset = rtems_fdt_phandle_to_offset(parent);
+    ptr = fdt_getprop(fdtp, offset, "ranges", &len);
+
+    if (len < 0) {
+      break;
+    }
+
+    nranges = len / sizeof(rtems_ofw_ranges);
+
+    offset = 0;
+    for (int i=0; i < nregs; i++) {
+      for (int j=0; j < nranges; j++) {
+        
+        range.parent_bus = fdt32_to_cpu(ptr[j].parent_bus);
+        range.child_bus = fdt32_to_cpu(ptr[j].child_bus);
+        range.size = fdt32_to_cpu(ptr[j].size);
+
+        if (buf[i].start >= range.child_bus &&
+            buf[i].start < range.child_bus + range.size) {
+          offset = range.parent_bus - range.child_bus;
+          break;
+        }
+
+      }
+      buf[i].start += offset;
+    }
+  }
+
+  return nregs;
+}
+
+int rtems_ofw_get_interrupts(
+  phandle_t            node,
+  rtems_vector_number *buf,
+  size_t               size
+)
+{
+  int rv;
+
+  rv = rtems_ofw_get_enc_prop(node, "interrupts", buf, size);
+
+  if (rv <= 0) {
+    return rv;
+  }
+
+  return MIN(size, rv) / sizeof(rtems_vector_number);
+}
+
+bool rtems_ofw_node_status( phandle_t node )
+{
+  int len;
+  const char buf[10];
+
+  len = rtems_ofw_get_prop(node, "status", (void *)&buf[0], sizeof(buf));
+  if ((len == -1) ||
+      (strncmp(buf, "okay", MIN(5, len)) == 0) ||
+      (strncmp(buf, "ok", MIN(3, len)) == 0)) {
+      return true;
+  }
+
+  return false;
+}
+
+phandle_t rtems_ofw_find_device_by_compat( const char *compat )
+{
+  int offset;
+
+  offset = fdt_node_offset_by_compatible(fdtp, -1, compat);
+  return rtems_fdt_offset_to_phandle(offset);
+}
diff --git a/spec/build/bsps/obj.yml b/spec/build/bsps/obj.yml
index a454783d51..b598d54d16 100644
--- a/spec/build/bsps/obj.yml
+++ b/spec/build/bsps/obj.yml
@@ -24,6 +24,10 @@ install:
   - bsps/include/bsp/u-boot.h
   - bsps/include/bsp/uart-output-char.h
   - bsps/include/bsp/utility.h
+- destination: ${BSP_INCLUDEDIR}/ofw
+  source:
+  - bsps/include/ofw/ofw.h
+  - bsps/include/ofw/ofw_compat.h
 - destination: ${BSP_INCLUDEDIR}/libchip
   source:
   - bsps/include/libchip/ata.h
@@ -96,4 +100,5 @@ source:
 - bsps/shared/dev/serial/serprobe.c
 - bsps/shared/start/bootcard.c
 - bsps/shared/rtems-version.c
+- bsps/shared/ofw/ofw.c
 type: build