1 // uart_virt.cc
2 // QEMU `virt` generic virtual platform
3 
4 
5 #include <hw.h>
6 #include <uart.h>
7 #include <pl011.h>
8 
9 
10 namespace Board {
11 namespace Uart {
12 
13 
14 namespace {
15 
16 constexpr uintptr_t UART_BASE = 0x9000000;
17 
18 } // anonymous namespace
19 
20 
21 void initialize()
22 {
23     Pl011::ControlRegister ControlRegister;
24     ControlRegister.m_u.m_Bits.m_UartEnable = 1;
25     ControlRegister.m_u.m_Bits.m_TransmitEnable = 1;
26     Hw::write32(UART_BASE + Pl011::CONTROL_REGISTER, ControlRegister.m_u.m_nValue);
27 }
28 
29 
30 void send(uint8_t nValue)
31 {
32     // spin while fifo is full
33     for (; ; )
34     {
35         Pl011::FlagRegister FlagRegister{Hw::read32(UART_BASE + Pl011::FLAG_REGISTER)};
36         if (!FlagRegister.m_u.m_Bits.m_TransmitFifoFull)
37             break;
38     }
39     Hw::write32(UART_BASE + Pl011::DATA_REGISTER, nValue);
40 }
41 
42 
43 uint8_t recv()
44 {
45     return 0;
46 }
47 
48 
49 } // namespace Uart
50 } // namespace Board