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-rw-r--r--include/linker_lists.h148
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+/*
+ * include/linker_lists.h
+ *
+ * Implementation of linker-generated arrays
+ *
+ * Copyright (C) 2012 Marek Vasut <marex@denx.de>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ */
+#ifndef __LINKER_LISTS_H__
+#define __LINKER_LISTS_H__
+
+/**
+ * ll_entry_declare() - Declare linker-generated array entry
+ * @_type: Data type of the entry
+ * @_name: Name of the entry
+ * @_section_u: Subsection of u_boot_list in which this entry is placed
+ * (with underscores instead of dots, for name concatenation)
+ * @_section_d: Subsection of u_boot_list in which this entry is placed
+ * (with dots, for section concatenation)
+ *
+ * This macro declares a variable that is placed into a linker-generated
+ * array. This is a basic building block for more advanced use of linker-
+ * generated arrays. The user is expected to build their own macro wrapper
+ * around this one.
+ *
+ * A variable declared using this macro must be compile-time initialized
+ * and is as such placed into subsection of special section, .u_boot_list.
+ * The subsection is specified by the _section_[u,d] parameter, see below.
+ * The base name of the variable is _name, yet the actual variable is
+ * declared as concatenation of
+ *
+ * %_u_boot_list_ + @_section_u + _ + @_name
+ *
+ * which ensures name uniqueness. This variable shall never be refered
+ * directly though.
+ *
+ * Special precaution must be made when using this macro:
+ * 1) The _type must not contain the "static" keyword, otherwise the entry
+ * is not generated.
+ *
+ * 2) The @_section_u and @_section_d variables must match, the only difference
+ * is that in @_section_u is every dot "." character present in @_section_d
+ * replaced by a single underscore "_" character in @_section_u. The actual
+ * purpose of these parameters is to select proper subsection in the global
+ * .u_boot_list section.
+ *
+ * 3) In case a section is declared that contains some array elements AND 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
+ * AND am 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, cmd.sub) = {
+ * .x = 3,
+ * .y = 4,
+ * };
+ */
+#define ll_entry_declare(_type, _name, _section_u, _section_d) \
+ _type _u_boot_list_##_section_u##_##_name __attribute__(( \
+ unused, aligned(4), \
+ section(".u_boot_list."#_section_d"."#_name)))
+
+/**
+ * ll_entry_start() - Point to first entry of linker-generated array
+ * @_type: Data type of the entry
+ * @_section_u: Subsection of u_boot_list in which this entry is placed
+ * (with underscores instead of dots)
+ *
+ * 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 _section_u argument.
+ *
+ * Example:
+ * struct my_sub_cmd *msc = ll_entry_start(struct my_sub_cmd, cmd_sub);
+ */
+#define ll_entry_start(_type, _section_u) \
+ ({ \
+ extern _type _u_boot_list_##_section_u##__start; \
+ _type *_ll_result = &_u_boot_list_##_section_u##__start;\
+ _ll_result; \
+ })
+
+/**
+ * ll_entry_count() - Return the number of elements in linker-generated array
+ * @_type: Data type of the entry
+ * @_section_u: Subsection of u_boot_list in which this entry is placed
+ * (with underscores instead of dots)
+ *
+ * This function returns the number of elements of a linker-generated array
+ * placed into subsection of .u_boot_list section specified by _section_u
+ * 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);
+ */
+#define ll_entry_count(_type, _section_u) \
+ ({ \
+ extern _type _u_boot_list_##_section_u##__start; \
+ extern _type _u_boot_list_##_section_u##__end; \
+ unsigned int _ll_result = \
+ &_u_boot_list_##_section_u##__end - \
+ &_u_boot_list_##_section_u##__start; \
+ _ll_result; \
+ })
+
+
+/**
+ * ll_entry_get() - Retrieve entry from linker-generated array by name
+ * @_type: Data type of the entry
+ * @_name: Name of the entry
+ * @_section_u: Subsection of u_boot_list in which this entry is placed
+ * (with underscores instead of dots)
+ *
+ * This function returns a pointer to a particular entry in LG-array
+ * identified by the subsection of u_boot_list where the entry resides
+ * and it's name.
+ *
+ * Example:
+ * ll_entry_declare(struct my_sub_cmd, my_sub_cmd, cmd_sub, 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, _section_u) \
+ ({ \
+ extern _type _u_boot_list_##_section_u##_##_name; \
+ _type *_ll_result = &_u_boot_list_##_section_u##_##_name;\
+ _ll_result; \
+ })
+
+#endif /* __LINKER_LISTS_H__ */