iomemtype = cpu_register_io_memory(io_index, foo_readfn,foo_writefn, s);
cpu_register_physical_memory(開始アドレス, サイズ, iomemtype);
io_index が 0 の時は新しい io 領域が作られる。
s は、CPU の io の状態を表現する任意の構造体。
サイズはターゲットのページサイズの倍数。
iomemtype (phys_offset) は、phys_offset & ~TARGET_PAGE_MASK) != 0 となる ( io memory page)。
/* mem_read and mem_write are arrays of functions containing the
function to access byte (index 0), word (index 1) and dword (index
2). Functions can be omitted with a NULL function pointer. The
registered functions may be modified dynamically later.
If io_index is non zero, the corresponding io zone is
modified. If it is zero, a new io zone is allocated. The return
value can be used with cpu_register_physical_memory(). (-1) is
returned if error. */
int cpu_register_io_memory(int io_index,
CPUReadMemoryFunc **mem_read,
CPUWriteMemoryFunc **mem_write,
void *opaque)
{
int i, subwidth = 0;
if (io_index <= 0) {
if (io_mem_nb >= IO_MEM_NB_ENTRIES)
return -1;
io_index = io_mem_nb++;
} else {
if (io_index >= IO_MEM_NB_ENTRIES)
return -1;
}
for(i = 0;i < 3; i++) {
if (!mem_read[i] || !mem_write[i])
subwidth = IO_MEM_SUBWIDTH;
io_mem_read[io_index][i] = mem_read[i];
io_mem_write[io_index][i] = mem_write[i];
}
io_mem_opaque[io_index] = opaque;
return (io_index << IO_MEM_SHIFT) | subwidth;
}
qemu-0.9.1/cpu-all.h
typedef void CPUWriteMemoryFunc(void *opaque,
target_phys_addr_t addr,
uint32_t value);
typedef uint32_t CPUReadMemoryFunc(void *opaque,
target_phys_addr_t addr);
int cpu_register_io_memory(int io_index,
CPUReadMemoryFunc **mem_read,
CPUWriteMemoryFunc **mem_write,
void *opaque);
