diff --git a/docs/memory.txt b/docs/memory.txt index 431d9ca88f..811b1bd3c5 100644 --- a/docs/memory.txt +++ b/docs/memory.txt @@ -41,8 +41,13 @@ MemoryRegion): MemoryRegionOps structure describing the callbacks. - ROM: a ROM memory region works like RAM for reads (directly accessing - a region of host memory), but like MMIO for writes (invoking a callback). - You initialize these with memory_region_init_rom_device(). + a region of host memory), and forbids writes. You initialize these with + memory_region_init_rom(). + +- ROM device: a ROM device memory region works like RAM for reads + (directly accessing a region of host memory), but like MMIO for + writes (invoking a callback). You initialize these with + memory_region_init_rom_device(). - IOMMU region: an IOMMU region translates addresses of accesses made to it and forwards them to some other target memory region. As the name suggests, diff --git a/include/exec/memory.h b/include/exec/memory.h index 23c7399131..2d9ea3c088 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -444,6 +444,25 @@ void memory_region_init_alias(MemoryRegion *mr, hwaddr offset, uint64_t size); +/** + * memory_region_init_rom: Initialize a ROM memory region. + * + * This has the same effect as calling memory_region_init_ram() + * and then marking the resulting region read-only with + * memory_region_set_readonly(). + * + * @mr: the #MemoryRegion to be initialized. + * @owner: the object that tracks the region's reference count + * @name: the name of the region. + * @size: size of the region. + * @errp: pointer to Error*, to store an error if it happens. + */ +void memory_region_init_rom(MemoryRegion *mr, + struct Object *owner, + const char *name, + uint64_t size, + Error **errp); + /** * memory_region_init_rom_device: Initialize a ROM memory region. Writes are * handled via callbacks. diff --git a/memory.c b/memory.c index 33799e810b..ecb565ea81 100644 --- a/memory.c +++ b/memory.c @@ -1376,6 +1376,21 @@ void memory_region_init_alias(MemoryRegion *mr, mr->alias_offset = offset; } +void memory_region_init_rom(MemoryRegion *mr, + struct Object *owner, + const char *name, + uint64_t size, + Error **errp) +{ + memory_region_init(mr, owner, name, size); + mr->ram = true; + mr->readonly = true; + mr->terminates = true; + mr->destructor = memory_region_destructor_ram; + mr->ram_block = qemu_ram_alloc(size, mr, errp); + mr->dirty_log_mask = tcg_enabled() ? (1 << DIRTY_MEMORY_CODE) : 0; +} + void memory_region_init_rom_device(MemoryRegion *mr, Object *owner, const MemoryRegionOps *ops,