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#include "memlayout.h"
//
// qemu -machine virt has a 16550a UART
// qemu/hw/riscv/virt.c
// http://byterunner.com/16550.html
//
// caller should lock.
//
// address of one of the registers
#define R(reg) ((unsigned int*)(UART0 + 4*(reg)))
void
uartinit(void)
{
// disable interrupts
*R(1) = 0x00;
// special mode to set baud rate
*R(3) = 0x80;
// LSB for baud rate of 38.4K
*R(0) = 0x03;
// MSB for baud rate of 38.4K
*R(1) = 0x00;
// leave set-baud mode,
// and set word length to 8 bits, no parity.
*R(3) = 0x03;
// reset and enable FIFOs.
*R(2) = 0x07;
}
void
uartputc(int c)
{
*R(0) = c;
}
static int
uartgetc(void)
{
}
void
uartintr(void)
{
}
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