doc: Replace DocBook with sphinx-based docs

The Linux kernel moved to sphinx-based documentation and got rid of the
DocBook based documentation quite a while ago. Hence, the DocBook
documentation for U-Boot should be converted as well.

To achieve this, import the necessary files from Linux v4.17, and
convert the current DocBook documentation (three files altogether) to
sphinx/reStructuredText.

For now, all old DocBook documentation was merged into a single
handbook, tentatively named "U-Boot Hacker Manual".

For some source files, the documentation style was changed to comply
with kernel-doc; no functional changes were applied.

Signed-off-by: Mario Six <mario.six@gdsys.cc>

1 files changed, 53 insertions, 111 deletions

diff --git a/include/linker_lists.h b/include/linker_lists.h
index e0759d446f..d775d041e0 100644
--- a/include/linker_lists.h
+++ b/include/linker_lists.h
@@ -20,87 +20,6 @@
 #if !defined(__ASSEMBLY__)
 
 /**
- * A linker list is constructed by grouping together linker input
- * sections, each containing one entry of the list. Each input section
- * contains a constant initialized variable which holds the entry's
- * content. Linker list input sections are constructed from the list
- * and entry names, plus a prefix which allows grouping all lists
- * together. Assuming _list and _entry are the list and entry names,
- * then the corresponding input section name is
- *
- *   .u_boot_list_ + 2_ + @_list + _2_ + @_entry
- *
- * and the C variable name is
- *
- *   _u_boot_list + _2_ + @_list + _2_ + @_entry
- *
- * This ensures uniqueness for both input section and C variable name.
- *
- * Note that the names differ only in the first character, "." for the
- * section and "_" for the variable, so that the linker cannot confuse
- * section and symbol names. From now on, both names will be referred
- * to as
- *
- *   %u_boot_list_ + 2_ + @_list + _2_ + @_entry
- *
- * Entry variables need never be referred to directly.
- *
- * The naming scheme for input sections allows grouping all linker lists
- * into a single linker output section and grouping all entries for a
- * single list.
- *
- * Note the two '_2_' constant components in the names: their presence
- * allows putting a start and end symbols around a list, by mapping
- * these symbols to sections names with components "1" (before) and
- * "3" (after) instead of "2" (within).
- * Start and end symbols for a list can generally be defined as
- *
- *   %u_boot_list_2_ + @_list + _1_...
- *   %u_boot_list_2_ + @_list + _3_...
- *
- * Start and end symbols for the whole of the linker lists area can be
- * defined as
- *
- *   %u_boot_list_1_...
- *   %u_boot_list_3_...
- *
- * Here is an example of the sorted sections which result from a list
- * "array" made up of three entries : "first", "second" and "third",
- * iterated at least once.
- *
- *   .u_boot_list_2_array_1
- *   .u_boot_list_2_array_2_first
- *   .u_boot_list_2_array_2_second
- *   .u_boot_list_2_array_2_third
- *   .u_boot_list_2_array_3
- *
- * If lists must be divided into sublists (e.g. for iterating only on
- * part of a list), one can simply give the list a name of the form
- * 'outer_2_inner', where 'outer' is the global list name and 'inner'
- * is the sub-list name. Iterators for the whole list should use the
- * global list name ("outer"); iterators for only a sub-list should use
- * the full sub-list name ("outer_2_inner").
- *
- * Here is an example of the sections generated from a global list
- * named "drivers", two sub-lists named "i2c" and "pci", and iterators
- * defined for the whole list and each sub-list:
- *
- *   %u_boot_list_2_drivers_1
- *   %u_boot_list_2_drivers_2_i2c_1
- *   %u_boot_list_2_drivers_2_i2c_2_first
- *   %u_boot_list_2_drivers_2_i2c_2_first
- *   %u_boot_list_2_drivers_2_i2c_2_second
- *   %u_boot_list_2_drivers_2_i2c_2_third
- *   %u_boot_list_2_drivers_2_i2c_3
- *   %u_boot_list_2_drivers_2_pci_1
- *   %u_boot_list_2_drivers_2_pci_2_first
- *   %u_boot_list_2_drivers_2_pci_2_second
- *   %u_boot_list_2_drivers_2_pci_2_third
- *   %u_boot_list_2_drivers_2_pci_3
- *   %u_boot_list_2_drivers_3
- */
-
-/**
  * llsym() - Access a linker-generated array entry
  * @_type:	Data type of the entry
  * @_name:	Name of the entry
@@ -134,16 +53,19 @@
  *    a subsection of this section is declared and contains some elements,
  *    it is imperative that the elements are of the same type.
  *
- * 4) In case an outer section is declared that contains some array elements
+ * 3) In case an outer section is declared that contains some array elements
  *    AND an inner subsection of this section is declared and contains some
  *    elements, then when traversing the outer section, even the elements of
  *    the inner sections are present in the array.
  *
  * Example:
- * ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
- *         .x = 3,
- *         .y = 4,
- * };
+ *
+ * ::
+ *
+ *   ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
+ *           .x = 3,
+ *           .y = 4,
+ *   };
  */
 #define ll_entry_declare(_type, _name, _list)				\
 	_type _u_boot_list_2_##_list##_2_##_name __aligned(4)		\
@@ -160,18 +82,20 @@
  * This is like ll_entry_declare() but creates multiple entries. It should
  * be assigned to an array.
  *
- * ll_entry_declare_list(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
- *	{ .x = 3, .y = 4 },
- *	{ .x = 8, .y = 2 },
- *	{ .x = 1, .y = 7 }
- * };
+ * ::
+ *
+ *   ll_entry_declare_list(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
+ *        { .x = 3, .y = 4 },
+ *        { .x = 8, .y = 2 },
+ *        { .x = 1, .y = 7 }
+ *   };
  */
 #define ll_entry_declare_list(_type, _name, _list)			\
 	_type _u_boot_list_2_##_list##_2_##_name[] __aligned(4)		\
 			__attribute__((unused,				\
 			section(".u_boot_list_2_"#_list"_2_"#_name)))
 
-/**
+/*
  * We need a 0-byte-size type for iterator symbols, and the compiler
  * does not allow defining objects of C type 'void'. Using an empty
  * struct is allowed by the compiler, but causes gcc versions 4.4 and
@@ -185,7 +109,7 @@
  * @_type:	Data type of the entry
  * @_list:	Name of the list in which this entry is placed
  *
- * This function returns (_type *) pointer to the very first entry of a
+ * This function returns ``(_type *)`` pointer to the very first entry of a
  * linker-generated array placed into subsection of .u_boot_list section
  * specified by _list argument.
  *
@@ -193,7 +117,10 @@
  * must be 2 and its rightmost index must be 1.
  *
  * Example:
- * struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
+ *
+ * ::
+ *
+ *   struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
  */
 #define ll_entry_start(_type, _list)					\
 ({									\
@@ -208,7 +135,7 @@
  * @_list:	Name of the list in which this entry is placed
  *		(with underscores instead of dots)
  *
- * This function returns (_type *) pointer after the very last entry of
+ * This function returns ``(_type *)`` pointer after the very last entry of
  * a linker-generated array placed into subsection of .u_boot_list
  * section specified by _list argument.
  *
@@ -216,7 +143,10 @@
  * must be 2 and its rightmost index must be 3.
  *
  * Example:
- * struct my_sub_cmd *msc = ll_entry_end(struct my_sub_cmd, cmd_sub);
+ *
+ * ::
+ *
+ *   struct my_sub_cmd *msc = ll_entry_end(struct my_sub_cmd, cmd_sub);
  */
 #define ll_entry_end(_type, _list)					\
 ({									\
@@ -234,11 +164,14 @@
  * argument. The result is of an unsigned int type.
  *
  * Example:
- * int i;
- * const unsigned int count = ll_entry_count(struct my_sub_cmd, cmd_sub);
- * struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
- * for (i = 0; i < count; i++, msc++)
- *         printf("Entry %i, x=%i y=%i\n", i, msc->x, msc->y);
+ *
+ * ::
+ *
+ *   int i;
+ *   const unsigned int count = ll_entry_count(struct my_sub_cmd, cmd_sub);
+ *   struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
+ *   for (i = 0; i < count; i++, msc++)
+ *           printf("Entry %i, x=%i y=%i\n", i, msc->x, msc->y);
  */
 #define ll_entry_count(_type, _list)					\
 	({								\
@@ -259,12 +192,15 @@
  * and it's name.
  *
  * Example:
- * ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
- *         .x = 3,
- *         .y = 4,
- * };
- * ...
- * struct my_sub_cmd *c = ll_entry_get(struct my_sub_cmd, my_sub_cmd, cmd_sub);
+ *
+ * ::
+ *
+ *   ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub) = {
+ *           .x = 3,
+ *           .y = 4,
+ *   };
+ *   ...
+ *   struct my_sub_cmd *c = ll_entry_get(struct my_sub_cmd, my_sub_cmd, cmd_sub);
  */
 #define ll_entry_get(_type, _name, _list)				\
 	({								\
@@ -278,14 +214,17 @@
  * ll_start() - Point to first entry of first linker-generated array
  * @_type:	Data type of the entry
  *
- * This function returns (_type *) pointer to the very first entry of
+ * This function returns ``(_type *)`` pointer to the very first entry of
  * the very first linker-generated array.
  *
  * Since this macro defines the start of the linker-generated arrays,
  * its leftmost index must be 1.
  *
  * Example:
- * struct my_sub_cmd *msc = ll_start(struct my_sub_cmd);
+ *
+ * ::
+ *
+ *   struct my_sub_cmd *msc = ll_start(struct my_sub_cmd);
  */
 #define ll_start(_type)							\
 ({									\
@@ -298,14 +237,17 @@
  * ll_end() - Point after last entry of last linker-generated array
  * @_type:	Data type of the entry
  *
- * This function returns (_type *) pointer after the very last entry of
+ * This function returns ``(_type *)`` pointer after the very last entry of
  * the very last linker-generated array.
  *
  * Since this macro defines the end of the linker-generated arrays,
  * its leftmost index must be 3.
  *
  * Example:
- * struct my_sub_cmd *msc = ll_end(struct my_sub_cmd);
+ *
+ * ::
+ *
+ *   struct my_sub_cmd *msc = ll_end(struct my_sub_cmd);
  */
 #define ll_end(_type)							\
 ({									\