Direct I/O :
指的是給定Index(0x00xFFFF),然後直接對Register 作存取
EFI code :
Status = IoDev->Io.Read ( IoDev, EfiCpuIoWidthUint8, Index, 1, &Data);
Status = IoDev->Io.Write( IoDev, EfiCpuIoWidthUint8, Index, 1, &Data);
Indirect I/O : (ISA mode)
指的是對一組 Index & Data port ,由index port 寫入register address
,此動作為定址要做讀寫的register。然後對Data port做讀寫即可。
Read :
Status = IoDev->Io.Write ( IoDev, EfiCpuIoWidthUint8, IPort, 1, &Index);
Status = IoDev->Io.Read ( IoDev, EfiCpuIoWidthUint8, DPort, 1, &Data);
Write:
Status = IoDev->Io.Write ( IoDev, EfiCpuIoWidthUint8, IPort, 1, &Index);
Status = IoDev->Io.Write ( IoDev, EfiCpuIoWidthUint8, DPort, 1, &Data);
Super I/O :
Super I/O 晶片
KBC 位於SuperIO 晶片裡,對外直接連接KB & Mouse 。對內(LPC bus)連接至PCH的PCI to LPC Bridge。
Super IO access :
對2E or 4E (configuration port) 寫入四組Value,進入 PnP Mode。
Exit the MB PnP Mode
Set bit 1 of the configure control register (Index=02h) to “1” to exit the MB PnP Mode.
Access Device's Register
Before accessing a selected register, the content of Index 07h must be changed to the LDN.
00h FDC
01h Serial Port 1
02h Serial Port 2
03h Parallel Port
04h Environment Controller
05h KBC(Keyboard)
06h KBC(Mouse)
07h GPIO
0Ah Consumer IR
60h, 61h, 62h, 63h 為KB BAR
70h 為中斷IRQ號碼,KB為IRQ1, Default 為1,
改70h為非01h會造成KB 無法使用,因為會無法access 正確的中斷向量表
p.s. Sub 說 mouse 也是使用KB BAR。
