1*0d498393Swdenk 2*0d498393SwdenkCommands are added to U-Boot by creating a new command structure. 3*0d498393SwdenkThis is done by first including command.h 4*0d498393Swdenk 5*0d498393SwdenkThen using the U_BOOT_CMD() macro to fill in a cmd_tbl_t struct. 6*0d498393Swdenk 7*0d498393SwdenkU_BOOT_CMD(name,maxargs,repeatable,command,"usage","help") 8*0d498393Swdenk 9*0d498393Swdenkname: is the name of the commad. THIS IS NOT a string. 10*0d498393Swdenkmaxargs: the maximumn numbers of arguments this function takes 11*0d498393Swdenkcommand: Function pointer (*cmd)(struct cmd_tbl_s *, int, int, char *[]); 12*0d498393Swdenkusage: Short description. This is a string 13*0d498393Swdenkhelp: long description. This is a string 14*0d498393Swdenk 15*0d498393Swdenk 16*0d498393Swdenk**** Behinde the scene ****** 17*0d498393Swdenk 18*0d498393SwdenkThe structure created is named with a special prefix (__u_boot_cmd_) 19*0d498393Swdenkand placed by the linker in a special section. 20*0d498393Swdenk 21*0d498393SwdenkThis makes it possible for the final link to extract all commands 22*0d498393Swdenkcompiled into any object code and construct a static array so the 23*0d498393Swdenkcommand can be found in an array starting at __u_boot_cmd_start. 24*0d498393Swdenk 25*0d498393SwdenkIf a new board is defined do not forget to define the command section 26*0d498393Swdenkby writing in u-boot.lds ($(TOPDIR)/board/boardname/u-boot.lds) these 27*0d498393Swdenk3 lines: 28*0d498393Swdenk 29*0d498393Swdenk __u_boot_cmd_start = .; 30*0d498393Swdenk .u_boot_cmd : { *(.u_boot_cmd) } 31*0d498393Swdenk __u_boot_cmd_end = .; 32