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#pragma once
template <typename T>
concept port_data_t = (is_same<T, uint8_t>::value || is_same<T, uint16_t>::value || is_same<T, uint32_t>::value);
template <uint16_t port_num, port_data_t T>
class Port {
public:
[[nodiscard]] T read() {
T result;
switch (sizeof(T)) {
case 1:
asm volatile("inb %1, %0" : "=a"(result) : "Nd"(port_num));
break;
case 2:
asm volatile("inw %1, %0" : "=a"(result) : "Nd"(port_num));
break;
case 4:
asm volatile("inl %1, %0" : "=a"(result) : "Nd"(port_num));
break;
}
return result;
}
void write(T data) {
switch (sizeof(T)) {
case 1:
asm volatile("outb %0, %1" : : "a"(data), "Nd"(port_num));
break;
case 2:
asm volatile("outw %0, %1" : : "a"(data), "Nd"(port_num));
break;
case 4:
asm volatile("outl %0, %1" : : "a"(data), "Nd"(port_num));
break;
}
}
};
/* Ports 0x3d0 to 0x3df are reserved for CGA; each port is 1 byte wide */
typedef Port<0x3d4, uint8_t> cga_idx_port;
typedef Port<0x3d5, uint8_t> cga_dat_port;
// 0x3d8 : mode select register
// 0x3d8 : color control register
// 0x3da : status register
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