1 /* 2 * structures and definitions for the int 15, ax=e820 memory map 3 * scheme. 4 * 5 * In a nutshell, arch/i386/boot/setup.S populates a scratch table 6 * in the empty_zero_block that contains a list of usable address/size 7 * duples. In arch/i386/kernel/setup.c, this information is 8 * transferred into the e820map, and in arch/i386/mm/init.c, that 9 * new information is used to mark pages reserved or not. 10 * 11 */ 12 #ifndef __E820_HEADER 13 #define __E820_HEADER 14 15 #define E820MAP 0x2d0 /* our map */ 16 #define E820MAX 32 /* number of entries in E820MAP */ 17 #define E820NR 0x1e8 /* # entries in E820MAP */ 18 19 #define E820_RAM 1 20 #define E820_RESERVED 2 21 #define E820_ACPI 3 /* usable as RAM once ACPI tables have been read */ 22 #define E820_NVS 4 23 24 #define HIGH_MEMORY (1024*1024) 25 26 #ifndef __ASSEMBLY__ 27 28 struct e820map { 29 int nr_map; 30 struct e820entry { 31 unsigned long long addr; /* start of memory segment */ 32 unsigned long long size; /* size of memory segment */ 33 unsigned long type; /* type of memory segment */ 34 } map[E820MAX]; 35 }; 36 37 extern struct e820map e820; 38 #endif/*!__ASSEMBLY__*/ 39 40 #endif/*__E820_HEADER*/ 41