reactos/ntoskrnl/ke/arm/arm_kprintf.c

   1 /*
   2  * PROJECT:         ReactOS Kernel
   3  * LICENSE:         BSD - See COPYING.ARM in the top level directory
   4  * FILE:            ntoskrnl/ke/arm/arm_kprintf.c
   5  * PURPOSE:         Early serial printf-style kernel debugging (ARM bringup)
   6  * PROGRAMMERS:     ReactOS Portable Systems Group
   7  */
   8
   9 /* INCLUDES *******************************************************************/
  10
  11 #include <ntoskrnl.h>
  12 #define NDEBUG
  13 #include <debug.h>
  14
  15 /* GLOBALS ********************************************************************/
  16
  17 //
  18 // UART Registers
  19 //
  20 #define UART_BASE (void*)0xe00f1000 /* HACK: freeldr mapped it here */
  21
  22 #define UART_PL01x_DR            (UART_BASE + 0x00)
  23 #define UART_PL01x_RSR           (UART_BASE + 0x04)
  24 #define UART_PL01x_ECR           (UART_BASE + 0x04)
  25 #define UART_PL01x_FR            (UART_BASE + 0x18)
  26 #define UART_PL011_IBRD          (UART_BASE + 0x24)
  27 #define UART_PL011_FBRD          (UART_BASE + 0x28)
  28 #define UART_PL011_LCRH          (UART_BASE + 0x2C)
  29 #define UART_PL011_CR            (UART_BASE + 0x30)
  30 #define UART_PL011_IMSC          (UART_BASE + 0x38)
  31
  32 //
  33 // LCR Values
  34 //
  35 #define UART_PL011_LCRH_WLEN_8   0x60
  36 #define UART_PL011_LCRH_FEN      0x10
  37
  38 //
  39 // FCR Values
  40 //
  41 #define UART_PL011_CR_UARTEN     0x01
  42 #define UART_PL011_CR_TXE        0x100
  43 #define UART_PL011_CR_RXE        0x200
  44
  45 //
  46 // LSR Values
  47 //
  48 #define UART_PL01x_FR_RXFE       0x10
  49 #define UART_PL01x_FR_TXFF       0x20
  50
  51 #define READ_REGISTER_ULONG(r) (*(volatile ULONG * const)(r))
  52 #define WRITE_REGISTER_ULONG(r, v) (*(volatile ULONG *)(r) = (v))
  53
  54 /* FUNCTIONS ******************************************************************/
  55
  56 VOID
  57 ArmVersaPutChar(IN INT Char)
  58 {
  59     //
  60     // Properly support new-lines
  61     //
  62     if (Char == '\n') ArmVersaPutChar('\r');
  63
  64     //
  65     // Wait for ready
  66     //
  67     while ((READ_REGISTER_ULONG(UART_PL01x_FR) & UART_PL01x_FR_TXFF) != 0);
  68
  69     //
  70     // Send the character
  71     //
  72     WRITE_REGISTER_ULONG(UART_PL01x_DR, Char);
  73 }
  74
  75 void arm_kprintf(const char *fmt, ...) {
  76         char buf[1024], *s;
  77         va_list args;
  78
  79         va_start(args, fmt);
  80         _vsnprintf(buf,sizeof(buf),fmt,args);
  81         va_end(args);
  82         for (s = buf; *s; s++)
  83                 ArmVersaPutChar(*s);
  84 }