kdserial.c

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/*
 * PROJECT:         ReactOS Kernel
 * LICENSE:         BSD - See COPYING.ARM in the top level directory
 * FILE:            ntoskrnl/kd/arm/kdbg.c
 * PURPOSE:         Serial Port Kernel Debugging Transport Library
 * PROGRAMMERS:     ReactOS Portable Systems Group
 */
 
/* INCLUDES *******************************************************************/
 
#include <ntoskrnl.h>
#include <arm/peripherals/pl011.h>
#define NDEBUG
#include <debug.h>
 
/* GLOBALS ********************************************************************/
 
CPPORT DefaultPort = {0, 0, 0};
 
//
// We need to build this in the configuration root and use KeFindConfigurationEntry
// to recover it later.
//
#define HACK 24000000
 
/* REACTOS FUNCTIONS **********************************************************/
 
BOOLEAN
NTAPI
KdPortInitializeEx(IN PCPPORT PortInformation,
                   IN ULONG ComPortNumber)
{
    ULONG Divider, Remainder, Fraction;
    ULONG Baudrate = PortInformation->BaudRate;
 
    //
    // Calculate baudrate clock divider and remainder
    //
    Divider   = HACK / (16 * Baudrate);
    Remainder = HACK % (16 * Baudrate);
 
    //
    // Calculate the fractional part
    //
    Fraction  = (8 * Remainder / Baudrate) >> 1;
    Fraction += (8 * Remainder / Baudrate) & 1;
 
    //
    // Disable interrupts
    //
    WRITE_REGISTER_ULONG((PULONG)UART_PL011_CR, 0);
 
    //
    // Set the baud rate
    //
    WRITE_REGISTER_ULONG((PULONG)UART_PL011_IBRD, Divider);
    WRITE_REGISTER_ULONG((PULONG)UART_PL011_FBRD, Fraction);
 
    //
    // Set 8 bits for data, 1 stop bit, no parity, FIFO enabled
    //
    WRITE_REGISTER_ULONG((PULONG)UART_PL011_LCRH,
                         UART_PL011_LCRH_WLEN_8 | UART_PL011_LCRH_FEN);
 
    //
    // Clear and enable FIFO
    //
    WRITE_REGISTER_ULONG((PULONG)UART_PL011_CR,
                         UART_PL011_CR_UARTEN |
                         UART_PL011_CR_TXE |
                         UART_PL011_CR_RXE);
 
    //
    // Done
    //
    return TRUE;
}
 
BOOLEAN
NTAPI
KdPortGetByteEx(IN PCPPORT PortInformation,
                OUT PUCHAR ByteReceived)
{
    UNIMPLEMENTED;
    while (TRUE);
    return FALSE;
}
 
VOID
NTAPI
KdPortPutByteEx(IN PCPPORT PortInformation,
                IN UCHAR ByteToSend)
{
    //
    // Wait for ready
    //
    while ((READ_REGISTER_ULONG((PULONG)UART_PL01x_FR) & UART_PL01x_FR_TXFF) != 0);
 
    //
    // Send the character
    //
    WRITE_REGISTER_ULONG((PULONG)UART_PL01x_DR, ByteToSend);
}
 
/* EOF */