diff --git a/libfdt/fdt.h b/libfdt/fdt.h
index 526aedb..a8cc756 100644
--- a/libfdt/fdt.h
+++ b/libfdt/fdt.h
@@ -54,7 +54,10 @@
 
 #ifndef __ASSEMBLY__
 
+/* The layout of the header for the devicetree */
 struct fdt_header {
+        /* header fields are stored in big-endian format */
+  
 	fdt32_t magic;			 /* magic word FDT_MAGIC */
 	fdt32_t totalsize;		 /* total size of DT block */
 	fdt32_t off_dt_struct;		 /* offset to structure */
@@ -73,9 +76,11 @@ struct fdt_header {
 	fdt32_t size_dt_struct;		 /* size of the structure block */
 };
 
+/* memory reservation block :
+  not used for general memory allocation*/
 struct fdt_reserve_entry {
-	fdt64_t address;
-	fdt64_t size;
+        fdt64_t address;                 /* physical address*/
+        fdt64_t size;                    /* size in bytes*/
 };
 
 struct fdt_node_header {
diff --git a/libpdbg/device.c b/libpdbg/device.c
index 3dc301f..c395e4c 100644
--- a/libpdbg/device.c
+++ b/libpdbg/device.c
@@ -392,6 +392,13 @@ void pdbg_target_set_property(struct pdbg_target *target, const char *name, cons
 	}
 }
 
+/**
+ * @brief Get the given property and return the size
+ * @param[in] target the pdbg_target
+ * @param[in] name the given class name
+ * @param[out] size the property size
+ * @return NULL
+ */
 void *pdbg_target_property(struct pdbg_target *target, const char *name, size_t *size)
 {
 	struct dt_property *p;
@@ -465,6 +472,12 @@ static const struct dt_property *dt_require_property(const struct pdbg_target *n
 	return p;
 }
 
+/**
+ * @brief Check to see if a given compatible matches that of a pdbg_target
+ * @param[in] target the pdbg_target
+ * @param[in] compatible the compatible string we want to match against
+ * @return bool true if pdbg_target is found given compatible
+ */
 bool pdbg_target_compatible(struct pdbg_target *target, const char *compatible)
 {
         char *c, *end;
@@ -620,7 +633,13 @@ static u32 dt_n_size_cells(const struct pdbg_target *node)
 	return dt_prop_get_u32_def(node->parent, "#size-cells", 1);
 }
 
-uint64_t pdbg_target_address(struct pdbg_target *target, uint64_t *out_size)
+/**
+ * @brief Get the address for a pdbg_target
+ * @param[in] target the pdbg_target
+ * @param[out] val pointer to return value, modified only if no error.
+ * @return int 0 iff successful, otherwise -1
+ */
+uint64_t pdbg_target_address(struct pdbg_target *target, uint64_t *size)
 {
 	const struct dt_property *p;
 	u32 na = dt_n_address_cells(target);
@@ -630,8 +649,8 @@ uint64_t pdbg_target_address(struct pdbg_target *target, uint64_t *out_size)
 	p = dt_require_property(target, "reg", -1);
 	n = (na + ns) * sizeof(u32);
 	assert(n <= p->len);
-	if (out_size)
-		*out_size = dt_get_number(p->prop + na * sizeof(u32), ns);
+	if (size)
+		*size = dt_get_number(p->prop + na * sizeof(u32), ns);
 	return dt_get_number(p->prop, na);
 }
 
@@ -654,6 +673,10 @@ struct pdbg_target *pdbg_target_from_path(struct pdbg_target *target, const char
 	return dt_find_by_path(target, path);
 }
 
+/**
+ * @brief Gets the head pdbg_target (root node)
+ * @return pdbg_target the root target
+ */
 struct pdbg_target *pdbg_target_root(void)
 {
 	return pdbg_dt_root;
diff --git a/libpdbg/libpdbg.c b/libpdbg/libpdbg.c
index c549497..aeb8839 100644
--- a/libpdbg/libpdbg.c
+++ b/libpdbg/libpdbg.c
@@ -6,6 +6,13 @@
 
 static pdbg_progress_tick_t progress_tick;
 
+/**
+ * @brief Find the next pdbg_target* given a class
+ * @param[in] class the class of interest
+ * @param[in] parent the head pdbg_target
+ * @param[in] last the last pdbg_target in the class
+ * @return the next pdbg_target* iff successful, otherwise NULL
+ */
 struct pdbg_target *__pdbg_next_target(const char *class, struct pdbg_target *parent, struct pdbg_target *last)
 {
 	struct pdbg_target *next, *tmp;
@@ -43,6 +50,12 @@ retry:
 	}
 }
 
+/**
+ * @brief Find the next child pdbg_target* given a parent target
+ * @param[in] parent the head pdbg_target
+ * @param[in] last the last pdbg_target in the class
+ * @return the next pdbg_target* iff successful, otherwise NULL
+ */
 struct pdbg_target *__pdbg_next_child_target(struct pdbg_target *parent, struct pdbg_target *last)
 {
 	if (!parent || list_empty(&parent->children))
@@ -57,11 +70,22 @@ struct pdbg_target *__pdbg_next_child_target(struct pdbg_target *parent, struct
 	return list_entry(last->list.next, struct pdbg_target, list);
 }
 
+/**
+ * @brief Get the pdbg_target status
+ * @param[in] target the pdbg_target
+ * @return pdbg_target_status the next pdbg_target status
+ */
 enum pdbg_target_status pdbg_target_status(struct pdbg_target *target)
 {
 	return target->status;
 }
 
+/**
+ * @brief Set the pdbg_target status
+ * @param[in] target pdbg_target
+ * @param[in] status the status to set
+ * @return void
+ */
 void pdbg_target_status_set(struct pdbg_target *target, enum pdbg_target_status status)
 {
 	/* It's a programming error for user code to attempt anything else so
@@ -71,7 +95,11 @@ void pdbg_target_status_set(struct pdbg_target *target, enum pdbg_target_status
 	target->status = status;
 }
 
-/* Searches up the tree and returns the first valid index found */
+/**
+ * @brief Searches up the tree and returns the first valid index found
+ * @param[in] target the pdbg_target
+ * @return uint32_t the target index
+ */
 uint32_t pdbg_target_index(struct pdbg_target *target)
 {
 	struct pdbg_target *dn;
@@ -84,7 +112,12 @@ uint32_t pdbg_target_index(struct pdbg_target *target)
 		return dn->index;
 }
 
-/* Find a target parent from the given class */
+/**
+ * @brief Find a target parent from the given class
+ * @param[in] class the given class
+ * @param[in] target the pdbg_target
+ * @return struct pdbg_target* the first parent target of the given class, otherwise NULL
+ */
 struct pdbg_target *pdbg_target_parent(const char *class, struct pdbg_target *target)
 {
 	struct pdbg_target *parent;
@@ -100,6 +133,13 @@ struct pdbg_target *pdbg_target_parent(const char *class, struct pdbg_target *ta
 	return NULL;
 }
 
+/**
+ * @brief Find a target parent from the given class
+ * @param[in] class the given class
+ * @param[in] target the pdbg_target
+ * @return struct pdbg_target* the first parent target of the given class, otherwise assert out
+ * @note Same as above but instead of returning NULL causes an assert failure
+ */
 struct pdbg_target *pdbg_target_require_parent(const char *class, struct pdbg_target *target)
 {
 	struct pdbg_target *parent = pdbg_target_parent(class, target);
@@ -108,7 +148,12 @@ struct pdbg_target *pdbg_target_require_parent(const char *class, struct pdbg_ta
 	return parent;
 }
 
-/* Searched up the tree for the first target of the right class and returns its index */
+/**
+ * @brief Searched up the tree for the first target of the right class and returns its index
+ * @param[in] target the pdbg_target
+ * @param[in] class the given class
+ * @return uint32_t target parent index, otherwise -1 if there's an error
+ */
 uint32_t pdbg_parent_index(struct pdbg_target *target, char *class)
 {
 	struct pdbg_target *parent;
@@ -120,21 +165,43 @@ uint32_t pdbg_parent_index(struct pdbg_target *target, char *class)
 		return -1;
 }
 
+/**
+ * @brief Get the target class name
+ * @param[in] target the pdbg_target
+ * @return char* the class name
+ */
 char *pdbg_target_class_name(struct pdbg_target *target)
 {
 	return target->class;
 }
 
+/**
+ * @brief Get the target name
+ * @param[in] target the pdbg_target
+ * @return char* the target name
+ */
 char *pdbg_target_name(struct pdbg_target *target)
 {
 	return target->name;
 }
 
+/**
+ * @brief Get the dn name
+ * @param[in] target the pdbg_target
+ * @return char* the dn name
+ */
 const char *pdbg_target_dn_name(struct pdbg_target *target)
 {
 	return target->dn_name;
 }
 
+/**
+ * @brief Get the given property value
+ * @param[in] target the pdbg_target
+ * @param[in] name the given class name
+ * @param[out] val the property value (uint32_t*)
+ * @return 0 iff successful, -1 otherwise
+ */
 int pdbg_target_u32_property(struct pdbg_target *target, const char *name, uint32_t *val)
 {
 	uint32_t *p;
@@ -150,23 +217,31 @@ int pdbg_target_u32_property(struct pdbg_target *target, const char *name, uint3
 	return 0;
 }
 
+/**
+ * @brief Searched up the tree for the first target of the right class and returns its index
+ * @param[in] target the pdbg_target
+ * @param[in] name the given class name
+ * @param[in] index of the u32 in the list of values
+ * @param[out] val pointer to return value, modified only if no error.
+ * @return int 0 iff successful, otherwise -1
+ */
 int pdbg_target_u32_index(struct pdbg_target *target, const char *name, int index, uint32_t *val)
 {
-        size_t len;
+	size_t len;
 	uint32_t *p;
 
-        p = pdbg_get_target_property(target, name, &len);
-        if (!p)
-                return -1;
+	p = pdbg_get_target_property(target, name, &len);
+	if (!p)
+		return -1;
 
-        assert(len >= (index+1)*sizeof(uint32_t));
+	assert(len >= (index+1)*sizeof(uint32_t));
 
 	/* FDT pointers should be aligned, but best to check */
 	assert(!((uintptr_t) p & 0x3));
 
-        /* Always aligned, so this works. */
-        *val = be32toh(p[index]);
-        return 0;
+	/* Always aligned, so this works. */
+	*val = be32toh(p[index]);
+	return 0;
 }
 
 void pdbg_progress_tick(uint64_t cur, uint64_t end)
diff --git a/libpdbg/libpdbg.h b/libpdbg/libpdbg.h
index 301c2c8..db19e14 100644
--- a/libpdbg/libpdbg.h
+++ b/libpdbg/libpdbg.h
@@ -6,22 +6,52 @@
 #include <stdbool.h>
 #include <stdarg.h>
 
-#include <stdbool.h>
-
 #include <ccan/short_types/short_types.h>
 
+/**
+ * @struct pdbg_target
+ * @brief PowerPC FSI Debugger target
+ */
 struct pdbg_target;
+
+/**
+ * @struct pdbg_target_class
+ * @brief PowerPC FSI Debugger target class
+ */
 struct pdbg_target_class;
 
 /* loops/iterators */
+
+/**
+ * @brief Find the next compatible target given @compat compat
+ * @param[in] parent the head pdbg_target
+ * @param[in] prev the last pdbg_target in the class
+ * @return the next compatible pdbg_target*
+ */
 struct pdbg_target *__pdbg_next_compatible_node(struct pdbg_target *root,
                                                 struct pdbg_target *prev,
                                                 const char *compat);
+
+/**
+ * @brief Find the next pdbg_target* given a class
+ * @param[in] klass the klass of interest
+ * @param[in] parent the head pdbg_target
+ * @param[in] last the last pdbg_target in the klass
+ * @return the next pdbg_target* iff successful, otherwise NULL
+ */
 struct pdbg_target *__pdbg_next_target(const char *klass, struct pdbg_target *parent, struct pdbg_target *last);
+
+/**
+ * @brief Find the next child pdbg_target* given a parent target
+ * @param[in] parent the head pdbg_target
+ * @param[in] last the last pdbg_target in the class
+ * @return the next pdbg_target* iff successful, otherwise NULL
+ */
 struct pdbg_target *__pdbg_next_child_target(struct pdbg_target *parent, struct pdbg_target *last);
 
-/*
- * Each target has a status associated with it. This is what each status means:
+/**
+ * @brief the pdbg_target states
+ * @note Each target has a status associated with it. This is what each status means:
  *
  * enabled     - the target exists and has been probed, will be released by
  *               the release call.
@@ -46,43 +76,116 @@ struct pdbg_target *__pdbg_next_child_target(struct pdbg_target *parent, struct
  * unneccessary probing by marking them disabled. If no status property exists
  * it defaults to "unknown".
  */
-enum pdbg_target_status {PDBG_TARGET_UNKNOWN = 0, PDBG_TARGET_ENABLED,
-			 PDBG_TARGET_DISABLED, PDBG_TARGET_MUSTEXIST,
-			 PDBG_TARGET_NONEXISTENT, PDBG_TARGET_RELEASED};
+enum pdbg_target_status {
+	PDBG_TARGET_UNKNOWN = 0, /**< UNKNOWN STATE     */
+	PDBG_TARGET_ENABLED,     /**< ENABLED STATE     */
+	PDBG_TARGET_DISABLED,    /**< DISABLED STATE    */
+	PDBG_TARGET_MUSTEXIST,   /**< MUSTEXIST STATE   */
+	PDBG_TARGET_NONEXISTENT, /**< NONEXISTENT STATE */
+	PDBG_TARGET_RELEASED,    /**< RELEASED STATE    */
+};
+
 
+/**
+ * @brief For each loop accross compatible targets
+ * @param[in] target the current pdbg_target
+ * @param[out] compat comptabile key to match against
+ */
 #define pdbg_for_each_compatible(parent, target, compat)		\
         for (target = NULL;                                             \
              (target = __pdbg_next_compatible_node(parent, target, compat)) != NULL;)
 
+/**
+ * @brief For each loop accross targets in the class (list)
+ * @param[in] parent the root pdbg_target
+ * @param[in] target the current pdbg_target
+ */
 #define pdbg_for_each_target(class, parent, target)			\
 	for (target = __pdbg_next_target(class, parent, NULL);		\
 	     target;							\
 	     target = __pdbg_next_target(class, parent, target))
 
+/**
+ * @brief For each loop accross class_targets (list)
+ * @param[in] class the class_target
+ * @param[in] target the current pdbg_target
+ */
 #define pdbg_for_each_class_target(class, target)		\
 	for (target = __pdbg_next_target(class, NULL, NULL);	\
 	     target;						\
 	     target = __pdbg_next_target(class, NULL, target))
 
+/**
+ * @brief For each loop accross class_targets (list)
+ * @param[in] parent the head pdbg_target
+ * @param[in] target the current pdbg_target
+ */
 #define pdbg_for_each_child_target(parent, target)	      \
 	for (target = __pdbg_next_child_target(parent, NULL); \
 	     target;					      \
 	     target = __pdbg_next_child_target(parent, target))
 
-/* Return the first parent target of the given class, or NULL if the given
- * target does not have a parent of the given class. */
+/**
+ * @brief Find a target parent from the given class
+ * @param[in] klass the given class
+ * @param[in] target the pdbg_target
+ * @return struct pdbg_target* the first parent target of the given class, otherwise NULL
+ */
 struct pdbg_target *pdbg_target_parent(const char *klass, struct pdbg_target *target);
 
-/* Same as above but instead of returning NULL causes an assert failure. */
+/**
+ * @brief Find a target parent from the given class
+ * @param[in] klass the given class
+ * @param[in] target the pdbg_target
+ * @return struct pdbg_target* the first parent target of the given class, otherwise assert out
+ * @note Same as above but instead of returning NULL causes an assert failure
+ */
 struct pdbg_target *pdbg_target_require_parent(const char *klass, struct pdbg_target *target);
 
-/* Set the given property. Will automatically add one if one doesn't exist */
+/**
+ * @brief Set the given property. Will automatically add one if one doesn't exist
+ * @param[in] name the given class name
+ * @param[in] target the pdbg_target
+ * @param[in] val the property to set
+ * @param[in] size the size
+ * @return void
+ */
 void pdbg_target_set_property(struct pdbg_target *target, const char *name, const void *val, size_t size);
 
-/* Get the given property and return the size */
+/**
+ * @brief Get the given property and return the size
+ * @param[in] target the pdbg_target
+ * @param[in] name the given class name
+ * @param[out] size the property size
+ * @return void* the pdbg_target property
+ */
 void *pdbg_target_property(struct pdbg_target *target, const char *name, size_t *size);
+
+/**
+ * @brief Get the given property value
+ * @param[in] target the pdbg_target
+ * @param[in] name the given class name
+ * @param[out] val the property value (uint32_t*)
+ * @return 0 iff successful, -1 otherwise
+ */
 int pdbg_target_u32_property(struct pdbg_target *target, const char *name, uint32_t *val);
+
+/**
+ * @brief Searched up the tree for the first target of the right class and returns its index
+ * @param[in] target the pdbg_target
+ * @param[in] name the given class name
+ * @param[in] index of the u32 in the list of values
+ * @param[out] val pointer to return value, modified only if no error.
+ * @return int 0 iff successful, otherwise -1
+ */
 int pdbg_target_u32_index(struct pdbg_target *target, const char *name, int index, uint32_t *val);
+
+/**
+ * @brief Get the address for a pdbg_target
+ * @param[in] target the pdbg_target
+ * @param[out] val pointer to return value, modified only if no error.
+ * @return int 0 iff successful, otherwise -1
+ */
 uint64_t pdbg_target_address(struct pdbg_target *target, uint64_t *size);
 
 /* Old deprecated for names for the above. Do not use for new projects
@@ -99,32 +202,150 @@ void pdbg_targets_init(void *fdt);
 void pdbg_target_probe_all(struct pdbg_target *parent);
 enum pdbg_target_status pdbg_target_probe(struct pdbg_target *target);
 void pdbg_target_release(struct pdbg_target *target);
+
+/**
+ * @brief Get the pdbg_target status
+ * @param[in] target the pdbg_target
+ * @return pdbg_target_status the next pdbg_target status
+ */
 enum pdbg_target_status pdbg_target_status(struct pdbg_target *target);
+
+/**
+ * @brief Set the pdbg_target status
+ * @param[in] target pdbg_target
+ * @param[in] status the status to set
+ * @return void
+ */
 void pdbg_target_status_set(struct pdbg_target *target, enum pdbg_target_status status);
+
+/**
+ * @brief Searches up the tree and returns the first valid index found
+ * @param[in] target the pdbg_target
+ * @return uint32_t the target index
+ */
 uint32_t pdbg_target_index(struct pdbg_target *target);
 char *pdbg_target_path(const struct pdbg_target *target);
 struct pdbg_target *pdbg_target_from_path(struct pdbg_target *target, const char *path);
+
+/**
+ * @brief Searched up the tree for the first target of the right class and returns its index
+ * @param[in] target the pdbg_target
+ * @param[in] class the given class
+ * @return uint32_t target parent index, otherwise -1 if there's an error
+ */
 uint32_t pdbg_parent_index(struct pdbg_target *target, char *klass);
+
+/**
+ * @brief Get the target class name
+ * @param[in] target the pdbg_target
+ * @return char* the class name
+ */
 char *pdbg_target_class_name(struct pdbg_target *target);
+
+/**
+ * @brief Get the target name
+ * @param[in] target the pdbg_target
+ * @return char* the target name
+ */
 char *pdbg_target_name(struct pdbg_target *target);
+
+/**
+ * @brief Get the dn name
+ * @param[in] target the pdbg_target
+ * @return char* the dn name
+ */
 const char *pdbg_target_dn_name(struct pdbg_target *target);
+
+/**
+ * @brief Gets the priv member of pdbg_target
+ * @param[in] target the pdbg_target
+ * @return void* to priv
+ */
 void *pdbg_target_priv(struct pdbg_target *target);
+
+/**
+ * @brief Sets the priv member of pdbg_target
+ * @param[in,out] target the pdbg_target
+ * @param[in] void* priv member to set
+ * @return void
+ */
 void pdbg_target_priv_set(struct pdbg_target *target, void *priv);
+
+/**
+ * @brief Gets the head pdbg_target (root node)
+ * @return pdbg_target the root target
+ */
 struct pdbg_target *pdbg_target_root(void);
+
+/**
+ * @brief Check to see if a given compatible matches that of a pdbg_target
+ * @param[in] target the pdbg_target
+ * @param[in] compatible the compatible string we want to match against
+ * @return bool true if pdbg_target is found given compatible
+ */
 bool pdbg_target_compatible(struct pdbg_target *target, const char *compatible);
 
-/* Translate an address offset for a target to absolute address in address
- * space of a "base" target.  */
+
+/**
+ * @brief Translate an address offset for a target to absolute address in address space of a "base" target
+ * @param[in] target the current pdbg_target
+ * @param[out] attr the target address offset
+ * @return struct pdbg_target* the current target
+ */
 struct pdbg_target *pdbg_address_absolute(struct pdbg_target *target, uint64_t *addr);
 
 /* Procedures */
+
+/**
+ * @brief FSI read
+ * @param[in] fsi_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the read data
+ * @return int 0 if successful, -1 otherwise
+ */
 int fsi_read(struct pdbg_target *target, uint32_t addr, uint32_t *val);
+
+/**
+ * @brief FSI write
+ * @param[in] fsi_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the write data
+ * @return int 0 if successful, -1 otherwise
+ */
 int fsi_write(struct pdbg_target *target, uint32_t addr, uint32_t val);
 
+/**
+ * @brief PIB read
+ * @param[in] pib_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the read data
+ * @return int 0 if successful, -1 otherwise
+ */
 int pib_read(struct pdbg_target *target, uint64_t addr, uint64_t *val);
+
+/**
+ * @brief PIB write
+ * @param[in] pib_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the write data
+ * @return int 0 if successful, -1 otherwise
+ */
 int pib_write(struct pdbg_target *target, uint64_t addr, uint64_t val);
+
+/**
+ * @brief Wait for a SCOM register addr to match value & mask == data
+ * @param[in] pib_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[in] mask the mask
+ * @param[in] data the data we want to match against
+ * @return int 0 if successful, -1 otherwise
+ */
 int pib_wait(struct pdbg_target *pib_dt, uint64_t addr, uint64_t mask, uint64_t data);
 
+/**
+ * @struct thread_regs
+ * @brief CPU thread registers
+ */
 struct thread_regs {
 	uint64_t nia;
 	uint64_t msr;
@@ -185,12 +406,32 @@ int ram_getxer(struct pdbg_target *thread, uint64_t *value);
 int ram_putxer(struct pdbg_target *thread, uint64_t value);
 int getring(struct pdbg_target *chiplet_target, uint64_t ring_addr, uint64_t ring_len, uint32_t result[]);
 
-enum pdbg_sleep_state {PDBG_THREAD_STATE_RUN, PDBG_THREAD_STATE_DOZE,
-		       PDBG_THREAD_STATE_NAP, PDBG_THREAD_STATE_SLEEP,
-		       PDBG_THREAD_STATE_STOP};
+/**
+ * @brief the pdbg thread states
+ */
+enum pdbg_sleep_state {
+	PDBG_THREAD_STATE_RUN,   /**< RUN STATE   */
+	PDBG_THREAD_STATE_DOZE,  /**< DOZE STATE  */
+	PDBG_THREAD_STATE_NAP,   /**< NAP STATE   */
+	PDBG_THREAD_STATE_SLEEP, /**< SLEEP STATE */
+	PDBG_THREAD_STATE_STOP,  /**< STOP STATE  */
+};
 
-enum pdbg_smt_state {PDBG_SMT_UNKNOWN, PDBG_SMT_1, PDBG_SMT_2, PDBG_SMT_4, PDBG_SMT_8};
+/**
+ * @brief the pdbg_smt states
+ */
+enum pdbg_smt_state {
+	PDBG_SMT_UNKNOWN, /**< UNKNOWN STATE */
+	PDBG_SMT_1,       /**< SMT_1 STATE   */
+	PDBG_SMT_2,       /**< SMT_2 STATE   */
+	PDBG_SMT_4,       /**< SMT_4 STATE   */
+	PDBG_SMT_8,       /**< SMT_8 STATE   */
+};
 
+/**
+ * @struct thread_state
+ * @brief Container of thread states
+ */
 struct thread_state {
 	bool active;
 	bool quiesced;
diff --git a/libpdbg/target.c b/libpdbg/target.c
index 37d3f54..eb97dbc 100644
--- a/libpdbg/target.c
+++ b/libpdbg/target.c
@@ -10,11 +10,27 @@
 #include "operations.h"
 #include "debug.h"
 
-struct list_head empty_list = LIST_HEAD_INIT(empty_list);
-struct list_head target_classes = LIST_HEAD_INIT(target_classes);
+/**
+ * @struct empty_list
+ * @brief Defines and initializes a list_head named empty_list
+ * @note this is a special node that refers to the linked list, without being a list node
+ */
+LIST_HEAD(empty_list);
 
-/* Work out the address to access based on the current target and
- * final class name */
+/**
+ * @struct target_classes
+ * @brief Defines and initializes a list_head named target_classes
+ * @note this is a special node that refers to the linked list, without being a list node
+ */
+LIST_HEAD(target_classes);
+
+/**
+ * @brief Work out the address to access
+ * @param[in] target the current target
+ * @param[in] name final class name
+ * @param[out] addr the address to access
+ * @return pdbg_target* the current target
+ */
 static struct pdbg_target *get_class_target_addr(struct pdbg_target *target, const char *name, uint64_t *addr)
 {
 	/* Check class */
@@ -36,6 +52,12 @@ static struct pdbg_target *get_class_target_addr(struct pdbg_target *target, con
 	return target;
 }
 
+/**
+ * @brief Translate an address offset for a target to absolute address in address space of a "base" target
+ * @param[in] target the current pdbg_target
+ * @param[out] attr the target address offset
+ * @return struct pdbg_target* the current target
+ */
 struct pdbg_target *pdbg_address_absolute(struct pdbg_target *target, uint64_t *addr)
 {
 	return get_class_target_addr(target, "pib", addr);
@@ -51,6 +73,13 @@ struct pdbg_target *pdbg_address_absolute(struct pdbg_target *target, uint64_t *
 #define PIB_DATA_IND_ERR PPC_BITMASK(33, 35)
 #define PIB_DATA_IND_DATA PPC_BITMASK(48, 63)
 
+/**
+ * @brief PIB indirect read
+ * @param[in] pib the pib target
+ * @param[in] addr the address
+ * @param[out] data the read data
+ * @return int 0 if successful, -1 otherwise
+ */
 static int pib_indirect_read(struct pib *pib, uint64_t addr, uint64_t *data)
 {
 	uint64_t indirect_addr;
@@ -85,6 +114,13 @@ static int pib_indirect_read(struct pib *pib, uint64_t addr, uint64_t *data)
 	return 0;
 }
 
+/**
+ * @brief PIB indirect write
+ * @param[in] pib the pib target
+ * @param[in] addr the address
+ * @param[out] data the write data
+ * @return int 0 if successful, -1 otherwise
+ */
 static int pib_indirect_write(struct pib *pib, uint64_t addr, uint64_t data)
 {
 	uint64_t indirect_addr;
@@ -118,6 +154,13 @@ static int pib_indirect_write(struct pib *pib, uint64_t addr, uint64_t data)
 	return 0;
 }
 
+/**
+ * @brief PIB read
+ * @param[in] pib_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the read data
+ * @return int 0 if successful, -1 otherwise
+ */
 int pib_read(struct pdbg_target *pib_dt, uint64_t addr, uint64_t *data)
 {
 	struct pib *pib;
@@ -135,6 +178,13 @@ int pib_read(struct pdbg_target *pib_dt, uint64_t addr, uint64_t *data)
 	return rc;
 }
 
+/**
+ * @brief PIB write
+ * @param[in] pib_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the write data
+ * @return int 0 if successful, -1 otherwise
+ */
 int pib_write(struct pdbg_target *pib_dt, uint64_t addr, uint64_t data)
 {
 	struct pib *pib;
@@ -152,7 +202,14 @@ int pib_write(struct pdbg_target *pib_dt, uint64_t addr, uint64_t data)
 	return rc;
 }
 
-/* Wait for a SCOM register addr to match value & mask == data */
+/**
+ * @brief Wait for a SCOM register addr to match value & mask == data
+ * @param[in] pib_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[in] mask the mask
+ * @param[in] data the data we want to match against
+ * @return int 0 if successful, -1 otherwise
+ */
 int pib_wait(struct pdbg_target *pib_dt, uint64_t addr, uint64_t mask, uint64_t data)
 {
 	struct pib *pib;
@@ -174,6 +231,13 @@ int pib_wait(struct pdbg_target *pib_dt, uint64_t addr, uint64_t mask, uint64_t
 	return 0;
 }
 
+/**
+ * @brief OPB read
+ * @param[in] opb_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the read data
+ * @return int 0 if successful, -1 otherwise
+ */
 int opb_read(struct pdbg_target *opb_dt, uint32_t addr, uint32_t *data)
 {
 	struct opb *opb;
@@ -184,6 +248,13 @@ int opb_read(struct pdbg_target *opb_dt, uint32_t addr, uint32_t *data)
 	return opb->read(opb, addr64, data);
 }
 
+/**
+ * @brief OPB write
+ * @param[in] opb_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the write data
+ * @return int 0 if successful, -1 otherwise
+ */
 int opb_write(struct pdbg_target *opb_dt, uint32_t addr, uint32_t data)
 {
 	struct opb *opb;
@@ -195,6 +266,13 @@ int opb_write(struct pdbg_target *opb_dt, uint32_t addr, uint32_t data)
 	return opb->write(opb, addr64, data);
 }
 
+/**
+ * @brief FSI read
+ * @param[in] fsi_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the read data
+ * @return int 0 if successful, -1 otherwise
+ */
 int fsi_read(struct pdbg_target *fsi_dt, uint32_t addr, uint32_t *data)
 {
 	struct fsi *fsi;
@@ -205,6 +283,13 @@ int fsi_read(struct pdbg_target *fsi_dt, uint32_t addr, uint32_t *data)
 	return fsi->read(fsi, addr64, data);
 }
 
+/**
+ * @brief FSI write
+ * @param[in] fsi_dt the pdbg_target
+ * @param[in] addr the address
+ * @param[out] data the write data
+ * @return int 0 if successful, -1 otherwise
+ */
 int fsi_write(struct pdbg_target *fsi_dt, uint32_t addr, uint32_t data)
 {
 	struct fsi *fsi;
@@ -216,13 +301,23 @@ int fsi_write(struct pdbg_target *fsi_dt, uint32_t addr, uint32_t data)
 	return fsi->write(fsi, addr64, data);
 }
 
+/**
+ * @brief Checks that a pdbg_target has a parent target
+ * @param[in] target A PowerPC FSI Debugger target
+ * @return struct pdbg_target* the input's parent target
+ * @note we assert out if the input is the list head
+ */
 struct pdbg_target *require_target_parent(struct pdbg_target *target)
 {
 	assert(target->parent);
 	return target->parent;
 }
 
-/* Finds the given class. Returns NULL if not found. */
+/**
+ * @brief Finds the target class given a name
+ * @param name the name of the class we want
+ * @return the found pdbg_target_class, otherwise NULL
+ */
 struct pdbg_target_class *find_target_class(const char *name)
 {
 	struct pdbg_target_class *target_class;
@@ -234,8 +329,12 @@ struct pdbg_target_class *find_target_class(const char *name)
 	return NULL;
 }
 
-/* Same as above but dies with an assert if the target class doesn't
- * exist */
+/**
+ * @brief Finds the target class given a name
+ * @param name the name of the class we want
+ * @return the found pdbg_target_class, otherwise assert out
+ * @note same as find_target_class but asserts out if the target class doesn't exist
+ */
 struct pdbg_target_class *require_target_class(const char *name)
 {
 	struct pdbg_target_class *target_class;
@@ -248,7 +347,11 @@ struct pdbg_target_class *require_target_class(const char *name)
 	return target_class;
 }
 
-/* Returns the existing class or allocates space for a new one */
+/**
+ * @brief Returns the existing class or allocates space for a new one
+ * @param name the name of the class we want
+ * @return the found or new pdbg_target_class
+ */
 struct pdbg_target_class *get_target_class(const char *name)
 {
 	struct pdbg_target_class *target_class;
@@ -266,8 +369,22 @@ struct pdbg_target_class *get_target_class(const char *name)
 	return target_class;
 }
 
+/**
+ * @struct __start_hw_units
+ * @brief declaration of __start_hw_units
+ */
 extern struct hw_unit_info *__start_hw_units;
+
+/**
+ * @struct __stop_hw_units
+ * @brief declaration of __stop_hw_units
+ */
 extern struct hw_init_info *__stop_hw_units;
+
+/**
+ * @brief Find a target given @compat a compatibility member
+ * @param[in] compat the given compatibility
+ */
 struct hw_unit_info *find_compatible_target(const char *compat)
 {
 	struct hw_unit_info **p;
@@ -282,8 +399,11 @@ struct hw_unit_info *find_compatible_target(const char *compat)
 	return NULL;
 }
 
-/* We walk the tree root down disabling targets which might/should
- * exist but don't */
+/**
+ * @brief We walk the tree root down disabling targets which might/should exist but don't
+ * @param[in] target the pdbg_target
+ * @return pdbg_target_status
+ */
 enum pdbg_target_status pdbg_target_probe(struct pdbg_target *target)
 {
 	struct pdbg_target *parent;
@@ -344,7 +464,11 @@ enum pdbg_target_status pdbg_target_probe(struct pdbg_target *target)
 	return PDBG_TARGET_ENABLED;
 }
 
-/* Releases a target by first recursively releasing all its children */
+/**
+ * @brief Releases a target by first recursively releasing all its children
+ * @param[in,out] target the pdbg_target
+ * @return void
+ */
 void pdbg_target_release(struct pdbg_target *target)
 {
 	struct pdbg_target *child;
@@ -361,8 +485,10 @@ void pdbg_target_release(struct pdbg_target *target)
 	target->status = PDBG_TARGET_RELEASED;
 }
 
-/*
- * Probe all targets in the device tree.
+/**
+ * @brief Probe all targets in the device tree.
+ * @param[in,out] target the pdbg_target
+ * @return void
  */
 void pdbg_target_probe_all(struct pdbg_target *parent)
 {
@@ -377,6 +503,12 @@ void pdbg_target_probe_all(struct pdbg_target *parent)
 	}
 }
 
+/**
+ * @brief Checks if the target is the given class
+ * @param[in] target the pdbg_target
+ * @param class the class name
+ * @return true if the pdbg_target is the class, otherwise false
+ */
 bool pdbg_target_is_class(struct pdbg_target *target, const char *class)
 {
 	if (!target || !target->class || !class)
@@ -384,11 +516,22 @@ bool pdbg_target_is_class(struct pdbg_target *target, const char *class)
 	return strcmp(target->class, class) == 0;
 }
 
+/**
+ * @brief Gets the priv member of pdbg_target
+ * @param[in] target the pdbg_target
+ * @return void* to priv
+ */
 void *pdbg_target_priv(struct pdbg_target *target)
 {
 	return target->priv;
 }
 
+/**
+ * @brief Sets the priv member of pdbg_target
+ * @param[in,out] target the pdbg_target
+ * @param[in] void* priv member to set
+ * @return void
+ */
 void pdbg_target_priv_set(struct pdbg_target *target, void *priv)
 {
 	target->priv = priv;
diff --git a/libpdbg/target.h b/libpdbg/target.h
index 729b122..0c4413b 100644
--- a/libpdbg/target.h
+++ b/libpdbg/target.h
@@ -23,14 +23,32 @@
 #include "compiler.h"
 #include "libpdbg.h"
 
-enum chip_type {CHIP_UNKNOWN, CHIP_P8, CHIP_P8NV, CHIP_P9};
+/** @file target.h */
 
+/** A chip type
+*   A list of currently supported processor chip types
+*/
+enum chip_type {
+	CHIP_UNKNOWN, /**< Unknown */
+	CHIP_P8,      /**< P8 */
+	CHIP_P8NV,    /**< P8 Prime */
+	CHIP_P9,      /**< P9 */
+};
+
+/**
+ * @struct pdbg_target_class
+ * @brief A container as a doubly linked list
+ */
 struct pdbg_target_class {
 	char *name;
 	struct list_head targets;
 	struct list_node class_head_link;
 };
 
+/**
+ * @struct pdbg_target
+ * @brief The PowerPC FSI Debugger target
+ */
 struct pdbg_target {
 	char *name;
 	char *compatible;
@@ -51,42 +69,108 @@ struct pdbg_target {
 	void *priv;
 };
 
+/**
+ * @brief Checks that a pdbg_target has a parent target
+ * @param[in] target A PowerPC FSI Debugger target
+ * @return struct pdbg_target* the input's parent target
+ * @note we assert out if the input is the list head
+ */
 struct pdbg_target *require_target_parent(struct pdbg_target *target);
+
+/**
+ * @brief Finds the given class
+ * @param name the name of the class we want
+ * @return the found pdbg_target_class, otherwise NULL
+ */
 struct pdbg_target_class *find_target_class(const char *name);
+
+/**
+ * @brief Finds the target class given a name
+ * @param name the name of the class we want
+ * @return the found pdbg_target_class, otherwise assert out
+ * @note same as find_target_class but asserts out if the target class doesn't exist
+ */
 struct pdbg_target_class *require_target_class(const char *name);
+
+/**
+ * @brief Returns the existing class or allocates space for a new one
+ * @param name the name of the class we want
+ * @return the found or new pdbg_target_class
+ */
 struct pdbg_target_class *get_target_class(const char *name);
+
+/**
+ * @brief Checks if the target is the given class
+ * @param[in] target the pdbg_target
+ * @param class the class name
+ * @return true if the pdbg_target is the class, otherwise false
+ */
 bool pdbg_target_is_class(struct pdbg_target *target, const char *class);
 
-/* This works and should be safe because struct pdbg_target is guaranteed to be
+/**
+ * @brief A macro that casts @x x as a translate function pointer
+ * @param[in] x
+ * @note This works and should be safe because struct pdbg_target is guaranteed to be
  * the first member of the specialised type (see the DECLARE_HW_UNIT definition
  * below). I'm not sure how sane it is though. Probably not very but it does
- * remove a bunch of tedious container_of() typing */
+ * remove a bunch of tedious container_of() typing
+ */
 #define translate_cast(x) (uint64_t (*)(struct pdbg_target *, uint64_t)) (x)
 
+/**
+ * @struct empty_list
+ * @brief Declares a list_head named empty_list
+ * @note this is a special node that refers to the linked list, without being a list node
+ */
 extern struct list_head empty_list;
+
+/**
+ * @struct target_classes
+ * @brief Declares list_head named target_classes
+ * @note this is a special node that refers to the linked list, without being a list node
+ */
 extern struct list_head target_classes;
 
+/**
+ * @brief A macro that iterates through a target_class (list) for a given class name
+ * @param[in] class_name the class name
+ * @param[in] target the target list
+ */
 #define for_each_class_target(class_name, target)			\
 	list_for_each((find_target_class(class_name) ? &require_target_class(class_name)->targets : &empty_list), target, class_link)
 
+/**
+ * @brief A macro that iterates through a list @target_class target classes
+ * @param[in] target_class the target class
+ */
 #define for_each_target_class(target_class)			\
 	list_for_each(&target_classes, target_class, class_head_link)
 
+/**
+ * @struct hw_unit_info
+ * @brief Declares HW unit information
+ */
 struct hw_unit_info {
 	void *hw_unit;
 	size_t size;
 };
+
+/**
+ * @brief Find a target given @compat a compatibility member
+ * @param[in] compat the given compatibility
+ */
 struct hw_unit_info *find_compatible_target(const char *compat);
 
-/* We can't pack the structs themselves directly into a special
+/**
+ * @brief A macro that packs pointers name into a special section
+ * @note We can't pack the structs themselves directly into a special
  * section because there doesn't seem to be any standard way of doing
  * that due to alignment rules. So instead we pack pointers into a
  * special section.
- *
  * If this macro fails to compile for you, you've probably not
  * declared the struct pdbg_target as the first member of the
  * container struct. Not doing so will break other assumptions.
- * */
+ */
 #define DECLARE_HW_UNIT(name)						\
 	static inline void name ##_hw_unit_check(void) {		\
 		((void)sizeof(char[1 - 2 * (container_off(typeof(name), target) != 0)])); \
@@ -95,6 +179,10 @@ struct hw_unit_info *find_compatible_target(const char *compat);
 	{ .hw_unit = &name, .size = sizeof(name) }; 	                \
 	const struct hw_unit_info __used __section("hw_units") *name ##_hw_unit_p = &name ##_hw_unit
 
+/**
+ * @struct htm
+ * @brief Defines a HTM target
+ */
 struct htm {
 	struct pdbg_target target;
 	int (*start)(struct htm *);
@@ -103,44 +191,104 @@ struct htm {
 	int (*dump)(struct htm *, char *);
 	int (*record)(struct htm *, char *);
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in htm
+ * @return struct htm*
+ */
 #define target_to_htm(x) container_of(x, struct htm, target)
 
+/**
+ * @struct adu
+ * @brief Defines a ADU target
+ */
 struct adu {
 	struct pdbg_target target;
 	int (*getmem)(struct adu *, uint64_t, uint64_t *, int);
 	int (*putmem)(struct adu *, uint64_t, uint64_t, int, int);
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in adu
+ * @return struct adu*
+ */
 #define target_to_adu(x) container_of(x, struct adu, target)
 
+/**
+ * @struct pib
+ * @brief Defines a PIB target
+ */
 struct pib {
 	struct pdbg_target target;
 	int (*read)(struct pib *, uint64_t, uint64_t *);
 	int (*write)(struct pib *, uint64_t, uint64_t);
 	void *priv;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in pib
+ * @return struct pib*
+ */
 #define target_to_pib(x) container_of(x, struct pib, target)
 
+/**
+ * @struct opb
+ * @brief Defines a OPB target
+ */
 struct opb {
 	struct pdbg_target target;
 	int (*read)(struct opb *, uint32_t, uint32_t *);
 	int (*write)(struct opb *, uint32_t, uint32_t);
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in opb
+ * @return struct opb*
+ */
 #define target_to_opb(x) container_of(x, struct opb, target)
 
+/**
+ * @struct fsi
+ * @brief Defines a FSI target
+ */
 struct fsi {
 	struct pdbg_target target;
 	int (*read)(struct fsi *, uint32_t, uint32_t *);
 	int (*write)(struct fsi *, uint32_t, uint32_t);
 	enum chip_type chip_type;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in fsi
+ * @return struct fsi*
+ */
 #define target_to_fsi(x) container_of(x, struct fsi, target)
 
+/**
+ * @struct core
+ * @brief Defines a CORE target
+ */
 struct core {
 	struct pdbg_target target;
 	bool release_spwkup;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in core
+ * @return struct core*
+ */
 #define target_to_core(x) container_of(x, struct core, target)
 
+/**
+ * @struct thread
+ * @brief Refers to CPU threads on the host
+ */
 struct thread {
 	struct pdbg_target target;
 	struct thread_state status;
@@ -163,46 +311,122 @@ struct thread {
 	int (*ram_putxer)(struct pdbg_target *, uint64_t value);
 	int (*enable_attn)(struct pdbg_target *);
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in thread
+ * @return struct thread*
+ */
 #define target_to_thread(x) container_of(x, struct thread, target)
 
-/* Place holder for chiplets which we just want translation for */
+/**
+ * @struct chiplet
+ * @brief Defines a CHIPLET target
+ * @note Place holder for chiplets which we just want translation for
+ */
 struct chiplet {
         struct pdbg_target target;
 	int (*getring)(struct chiplet *, uint64_t, int64_t, uint32_t[]);
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in chiplet
+ * @return struct chiplet*
+ */
 #define target_to_chiplet(x) container_of(x, struct chiplet, target)
 
+/**
+ * @struct xbus
+ * @brief Defines a XBUS target
+ */
 struct xbus {
 	struct pdbg_target target;
 	uint32_t ring_id;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in xbus
+ * @return struct xbus*
+ */
 #define target_to_xbus(x) container_of(x, struct xbus, target)
 
+/**
+ * @struct mcs
+ * @brief Defines a MCS target
+ */
 struct mcs {
 	struct pdbg_target target;
 	uint32_t chip_unit;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in mcs
+ * @return struct mcs*
+ */
 #define target_to_mcs(x) container_of(x, struct mcs, target)
 
+/**
+ * @struct pec
+ * @brief Defines a PEC target
+ */
 struct pec {
 	struct pdbg_target target;
 	uint32_t chip_unit;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in pec
+ * @return struct pec*
+ */
 #define target_to_pec(x) container_of(x, struct pec, target)
 
+/**
+ * @struct eq
+ * @brief Defines a EQ target
+ */
 struct eq {
 	struct pdbg_target target;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in eq
+ * @return struct eq*
+ */
 #define target_to_eq(x) container_of(x, struct eq, target);
 
+/**
+ * @struct ex
+ * @brief Defines a EX target
+ */
 struct ex {
 	struct pdbg_target target;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in ex
+ * @return struct ex*
+ */
 #define target_to_ex(x) container_of(x, struct ex, target)
 
+/**
+ * @struct ec
+ * @brief Defines a EC target
+ */
 struct ec {
 	struct pdbg_target target;
 };
+
+/**
+ * @brief A macro that retrieves the struct given a pointer 'target' member
+ * @param[in] x A pointer to the 'target' field in ec
+ * @return struct ec*
+ */
 #define target_to_ec(x) container_of(x, struct ec, target)
 
 #endif
