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#include "uart.h"
#include "fdt.h"
volatile uint32_t* uart;
void uart_putchar(uint8_t ch)
{
#ifdef __riscv_atomic
int32_t r;
do {
__asm__ __volatile__ (
"amoor.w %0, %2, %1\n"
: "=r" (r), "+A" (uart[UART_REG_TXFIFO])
: "r" (ch));
} while (r < 0);
#else
volatile uint32_t *tx = uart + UART_REG_TXFIFO;
while ((int32_t)(*tx) < 0);
*tx = ch;
#endif
}
int uart_getchar()
{
int32_t ch = uart[UART_REG_RXFIFO];
if (ch < 0) return -1;
return ch;
}
void query_uart(uintptr_t dtb)
{
uart = 0; // (void*)fdt_get_reg(dtb, "sifive,uart0");
if (!uart) return;
// Enable Rx/Tx channels
uart[UART_REG_TXCTRL] = UART_TXEN;
uart[UART_REG_RXCTRL] = UART_RXEN;
}
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