湖南建立网站营销设计,网页链接制作生成,网站建设技术支持有什么,潍坊网页网站制作linker list是利用lds 描述符实现同类型数据连续排布的一种机制。 下面是uboot里面的应用说明
lds文件里面需要增加section描述#xff1a; . ALIGN(4);.u_boot_list : {KEEP(*(SORT(.u_boot_list*)));}linker_list.h:
/* SPDX-License-Identifier: GPL-2.0 */
/** include…linker list是利用lds 描述符实现同类型数据连续排布的一种机制。 下面是uboot里面的应用说明
lds文件里面需要增加section描述
. ALIGN(4);.u_boot_list : {KEEP(*(SORT(.u_boot_list*)));}linker_list.h:
/* SPDX-License-Identifier: GPL-2.0 */
/** include/linker_lists.h** Implementation of linker-generated arrays** Copyright (C) 2012 Marek Vasut marexdenx.de*/#ifndef __LINKER_LISTS_H__
#define __LINKER_LISTS_H__#include linux/compiler.h/** There is no use in including this from ASM files.* So just dont define anything when included from ASM.*/#if !defined(__ASSEMBLY__)/*** llsym() - Access a linker-generated array entry* _type: Data type of the entry* _name: Name of the entry* _list: name of the list. Should contain only characters allowed* in a C variable name!*/
#define llsym(_type, _name, _list) \((_type *)_u_boot_list_2_##_list##_2_##_name)/*** ll_entry_declare() - Declare linker-generated array entry* _type: Data type of the entry* _name: Name of the entry* _list: name of the list. Should contain only characters allowed* in a C variable name!** 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.** Special precaution must be made when using this macro:** 1) The _type must not contain the static keyword, otherwise the* entry is generated and can be iterated but is listed in the map* file and cannot be retrieved by name.** 2) 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.** 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,* };*/
#define ll_entry_declare(_type, _name, _list) \_type _u_boot_list_2_##_list##_2_##_name __aligned(4) \__attribute__((unused, \section(.u_boot_list_2_#_list_2_#_name)))/*** ll_entry_declare_list() - Declare a list of link-generated array entries* _type: Data type of each entry* _name: Name of the entry* _list: name of the list. Should contain only characters allowed* in a C variable name!** 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 }* };*/
#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* below to complain about aliasing. Therefore we use the next best* thing: zero-sized arrays, which are both 0-byte-size and exempt from* aliasing warnings.*//*** ll_entry_start() - Point to first entry of linker-generated array* _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* linker-generated array placed into subsection of .u_boot_list section* specified by _list argument.** Since this macro defines an array start symbol, its leftmost index* 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);*/
#define ll_entry_start(_type, _list) \
({ \static char start[0] __aligned(4) __attribute__((unused, \section(.u_boot_list_2_#_list_1))); \(_type *)start; \
})/*** ll_entry_end() - Point after last entry of linker-generated array* _type: Data type of the entry* _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* a linker-generated array placed into subsection of .u_boot_list* section specified by _list argument.** Since this macro defines an array end symbol, its leftmost index* 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);*/
#define ll_entry_end(_type, _list) \
({ \static char end[0] __aligned(4) __attribute__((unused, \section(.u_boot_list_2_#_list_3))); \(_type *)end; \
})
/*** ll_entry_count() - Return the number of elements in linker-generated array* _type: Data type of the entry* _list: Name of the list of which the number of elements is computed** This function returns the number of elements of a linker-generated array* placed into subsection of .u_boot_list section specified by _list* 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, _list) \({ \_type *start ll_entry_start(_type, _list); \_type *end ll_entry_end(_type, _list); \unsigned int _ll_result end - 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* _list: Name of the list in which this entry is placed** This function returns a pointer to a particular entry in linker-generated* array identified by the subsection of u_boot_list where the entry resides* and its 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);*/
#define ll_entry_get(_type, _name, _list) \({ \extern _type _u_boot_list_2_##_list##_2_##_name; \_type *_ll_result \_u_boot_list_2_##_list##_2_##_name; \_ll_result; \})/*** 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* 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);*/
#define ll_start(_type) \
({ \static char start[0] __aligned(4) __attribute__((unused, \section(.u_boot_list_1))); \(_type *)start; \
})/*** 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* 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);*/
#define ll_end(_type) \
({ \static char end[0] __aligned(4) __attribute__((unused, \section(.u_boot_list_3))); \(_type *)end; \
})#endif /* __ASSEMBLY__ */#endif /* __LINKER_LISTS_H__ */ll_entry_declare_list 和ll_entry_declare差别是前者是数组声明一次可以声明多个条目后者只声明定义一个条目。
ll_entry_start(_type, _list) 获取该类型列表首个条目地址
ll_entry_get(_type, _name, _list) 根据名字 返回条目地址
ll_entry_count(_type, _list) 返回该类型条目数
使用实例
参考driver的定义
struct driver {char *name;enum uclass_id id;const struct udevice_id *of_match;int (*bind)(struct udevice *dev);int (*probe)(struct udevice *dev);int (*remove)(struct udevice *dev);int (*unbind)(struct udevice *dev);int (*ofdata_to_platdata)(struct udevice *dev);int (*child_post_bind)(struct udevice *dev);int (*child_pre_probe)(struct udevice *dev);int (*child_post_remove)(struct udevice *dev);int priv_auto_alloc_size;int platdata_auto_alloc_size;int per_child_auto_alloc_size;int per_child_platdata_auto_alloc_size;const void *ops; /* driver-specific operations */uint32_t flags;
};/* Declare a new U-Boot driver */
#define U_BOOT_DRIVER(__name) \ll_entry_declare(struct driver, __name, driver)usb hub driver
U_BOOT_DRIVER(usb_generic_hub) { .name “usb_hub”, .id UCLASS_USB_HUB, .of_match usb_hub_ids, .flags DM_FLAG_ALLOC_PRIV_DMA, };
