text: /*
   * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
   *
   * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   * 
   * This file contains Original Code and/or Modifications of Original Code
   * as defined in and that are subject to the Apple Public Source License
   * Version 2.0 (the 'License'). You may not use this file except in
   * compliance with the License. The rights granted to you under the License
   * may not be used to create, or enable the creation or redistribution of,
   * unlawful or unlicensed copies of an Apple operating system, or to
   * circumvent, violate, or enable the circumvention or violation of, any
   * terms of an Apple operating system software license agreement.
   * 
   * Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this file.
   * 
   * The Original Code and all software distributed under the License are
   * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
   * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   * 
   * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
   */
  /*
   * file: pe_kprintf.c
   *    i386 platform expert debugging output initialization.
   */
  #include <stdarg.h>
  #include <machine/machine_routines.h>
  #include <pexpert/pexpert.h>
  #include <kern/debug.h>
  #include <kern/simple_lock.h>
  #include <i386/machine_cpu.h>
  #include <i386/mp.h>
  #include <machine/pal_routines.h>
  #include <i386/proc_reg.h>
  #include <os/log_private.h>
  #include <libkern/section_keywords.h>
  
  /* Globals */
  void (*PE_kputc)(char c);
  
  #if DEVELOPMENT || DEBUG 
  /* DEBUG kernel starts with true serial, but
   * may later disable or switch to video
   * console */
  SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = FALSE;
  #else
  SECURITY_READ_ONLY_LATE(unsigned int) disable_serial_output = TRUE;
  #endif
  
  decl_simple_lock_data(static, kprintf_lock)
  
  void PE_init_kprintf(boolean_t vm_initialized)
  {
  	unsigned int	boot_arg;
  
  	if (PE_state.initialized == FALSE)
  		panic("Platform Expert not initialized");
  
  	if (!vm_initialized) {
  		unsigned int new_disable_serial_output = TRUE;
  
  		simple_lock_init(&kprintf_lock, 0);
  
  		if (PE_parse_boot_argn("debug", &boot_arg, sizeof (boot_arg)))
  			if (boot_arg & DB_KPRT)
  				new_disable_serial_output = FALSE;
  
  		/* If we are newly enabling serial, make sure we only
  		 * call pal_serial_init() if our previous state was
  		 * not enabled */
  		if (!new_disable_serial_output && (!disable_serial_output || pal_serial_init()))
  			PE_kputc = pal_serial_putc;
  		else
  			PE_kputc = cnputc;
  
  		disable_serial_output = new_disable_serial_output;
  	}
  }
  
  #if CONFIG_NO_KPRINTF_STRINGS
  /* Prevent CPP from breaking the definition below */
  #undef kprintf
  #endif
  
  #ifdef MP_DEBUG
  static void _kprintf(const char *format, ...)
  {
  	va_list   listp;
  
          va_start(listp, format);
          _doprnt(format, &listp, PE_kputc, 16);
          va_end(listp);
  }
  #define MP_DEBUG_KPRINTF(x...)	_kprintf(x)
  #else  /* MP_DEBUG */
  #define MP_DEBUG_KPRINTF(x...)
  #endif /* MP_DEBUG */
  
  static int cpu_last_locked = 0;
  
  __attribute__((noinline,not_tail_called))
  void kprintf(const char *fmt, ...)
  {
  	va_list    listp;
  	va_list    listp2;
  	boolean_t  state;
  	void      *caller = __builtin_return_address(0);
  
  	if (!disable_serial_output) {
  		boolean_t early = FALSE;
  		if (rdmsr64(MSR_IA32_GS_BASE) == 0) {
  			early = TRUE;
  		}
  		/* If PE_kputc has not yet been initialized, don't
  		 * take any locks, just dump to serial */
  		if (!PE_kputc || early) {
  			va_start(listp, fmt);
  			va_copy(listp2, listp);
  
  			_doprnt_log(fmt, &listp, pal_serial_putc, 16);
  			va_end(listp);
  
  			// If interrupts are enabled
  			if (ml_get_interrupts_enabled()) {
  				os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp2, caller);
  			}
  			va_end(listp2);
  			return;
  		}
  
  		/*
  		 * Spin to get kprintf lock but poll for incoming signals
  		 * while interrupts are masked.
  		 */
  		state = ml_set_interrupts_enabled(FALSE);
  
  		pal_preemption_assert();
  
  		while (!simple_lock_try(&kprintf_lock)) {
  			(void) cpu_signal_handler(NULL);
  		}
  
  		if (cpu_number() != cpu_last_locked) {
  			MP_DEBUG_KPRINTF("[cpu%d...]\n", cpu_number());
  			cpu_last_locked = cpu_number();
  		}
  
  		va_start(listp, fmt);
  		va_copy(listp2, listp);
  		_doprnt(fmt, &listp, PE_kputc, 16);
  		va_end(listp);
  
  		simple_unlock(&kprintf_lock);
  		ml_set_interrupts_enabled(state);
  
  		// If interrupts are enabled
  		if (ml_get_interrupts_enabled()) {
  			os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp2, caller);
  		}
  		va_end(listp2);
  
  	}
  	else {
  		if (ml_get_interrupts_enabled()) {
  			va_start(listp, fmt);
  			os_log_with_args(OS_LOG_DEFAULT, OS_LOG_TYPE_DEFAULT, fmt, listp, caller);
  			va_end(listp);
  		}
  	}
  }
  
  
  
  extern void kprintf_break_lock(void);
  void
  kprintf_break_lock(void)
  {
  	simple_lock_init(&kprintf_lock, 0);
  }
  