class IndirectIo

IndirectIo is a replacement for RegisterMmio that sequences access to a

common PCI device construct where two registers, "index" and "data", are

used to read and write a much larger store, logically private_store[index] =

data.

Example usage from VGA:

typedef IndirectIo

<

0x03D4, 0x03D5> CrtcIo;

class CrtcReg : public hwreg::RegisterBase

<CrtcReg

, uint8_t> {

public:

static auto Get(size_t offset) : { return hwreg::RegisterAddr

<CrtcReg

>(offset); }

};

...

void SetMode3(volatile void* mmio) {

auto io = CrtcIo(mmio);

CrtcReg::Get(0x00).ReadFrom(

&io

).set_reg_value(0x5F).WriteTo(

&io

);

CrtcReg::Get(0x01).ReadFrom(

&io

).set_reg_value(0x4F).WriteTo(

&io

);

CrtcReg::Get(0x02).ReadFrom(

&io

).set_reg_value(0x50).WriteTo(

&io

);

CrtcReg::Get(0x03).ReadFrom(

&io

).set_reg_value(0x82).WriteTo(

&io

);

CrtcReg::Get(0x04).ReadFrom(

&io

).set_reg_value(0x55).WriteTo(

&io

);

CrtcReg::Get(0x05).ReadFrom(

&io

).set_reg_value(0x81).WriteTo(

&io

);

}