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| -rw-r--r-- | include/hw/boards.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/include/hw/boards.h b/include/hw/boards.h index 76ce0219ff..3143727cad 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -9,6 +9,34 @@ #include "qom/object.h" #include "qom/cpu.h" +/** + * memory_region_allocate_system_memory - Allocate a board's main memory + * @mr: the #MemoryRegion to be initialized + * @owner: the object that tracks the region's reference count + * @name: name of the memory region + * @ram_size: size of the region in bytes + * + * This function allocates the main memory for a board model, and + * initializes @mr appropriately. It also arranges for the memory + * to be migrated (by calling vmstate_register_ram_global()). + * + * Memory allocated via this function will be backed with the memory + * backend the user provided using "-mem-path" or "-numa node,memdev=..." + * if appropriate; this is typically used to cause host huge pages to be + * used. This function should therefore be called by a board exactly once, + * for the primary or largest RAM area it implements. + * + * For boards where the major RAM is split into two parts in the memory + * map, you can deal with this by calling memory_region_allocate_system_memory() + * once to get a MemoryRegion with enough RAM for both parts, and then + * creating alias MemoryRegions via memory_region_init_alias() which + * alias into different parts of the RAM MemoryRegion and can be mapped + * into the memory map in the appropriate places. + * + * Smaller pieces of memory (display RAM, static RAMs, etc) don't need + * to be backed via the -mem-path memory backend and can simply + * be created via memory_region_init_ram(). + */ void memory_region_allocate_system_memory(MemoryRegion *mr, Object *owner, const char *name, uint64_t ram_size); |