/* @r{kernel.c - the C part of the kernel} *//* @r{Copyright (C) 1999  Free Software Foundation, Inc.      This program is free software; you can redistribute it and/or modify   it under the terms of the GNU General Public License as published by   the Free Software Foundation; either version 2 of the License, or   (at your option) any later version.      This program is distributed in the hope that it will be useful,   but WITHOUT ANY WARRANTY; without even the implied warranty of   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the   GNU General Public License for more details.      You should have received a copy of the GNU General Public License   along with this program; if not, write to the Free Software   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.} */#include <multiboot.h>/* @r{Macros.} *//* @r{Check if the bit BIT in FLAGS is set.} */#define CHECK_FLAG(flags,bit)   ((flags) & (1 << (bit)))/* @r{Some screen stuff.} *//* @r{The number of columns.} */#define COLUMNS                 80/* @r{The number of lines.} */#define LINES                   24/* @r{The attribute of an character.} */#define ATTRIBUTE               7/* @r{The video memory address.} */#define VIDEO                   0xB8000/* @r{Variables.} *//* @r{Save the X position.} */static int xpos;/* @r{Save the Y position.} */static int ypos;/* @r{Point to the video memory.} */static volatile unsigned char *video;/* @r{Forward declarations.} */void cmain (unsigned long magic, unsigned long addr);static void cls (void);static void itoa (char *buf, int base, int d);static void putchar (int c);void printf (const char *format, ...);/* @r{Check if MAGIC is valid and print the Multiboot information structure   pointed by ADDR.} */voidcmain (unsigned long magic, unsigned long addr)@{  multiboot_info_t *mbi;    /* @r{Clear the screen.} */  cls ();  /* @r{Am I booted by a Multiboot-compliant boot loader?} */  if (magic != MULTIBOOT_BOOTLOADER_MAGIC)    @{      printf ("Invalid magic number: 0x%x\n", (unsigned) magic);      return;    @}  /* @r{Set MBI to the address of the Multiboot information structure.} */  mbi = (multiboot_info_t *) addr;  /* @r{Print out the flags.} */  printf ("flags = 0x%x\n", (unsigned) mbi->flags);  /* @r{Are mem_* valid?} */  if (CHECK_FLAG (mbi->flags, 0))    printf ("mem_lower = %uKB, mem_upper = %uKB\n",            (unsigned) mbi->mem_lower, (unsigned) mbi->mem_upper);  /* @r{Is boot_device valid?} */  if (CHECK_FLAG (mbi->flags, 1))    printf ("boot_device = 0x%x\n", (unsigned) mbi->boot_device);    /* @r{Is the command line passed?} */  if (CHECK_FLAG (mbi->flags, 2))    printf ("cmdline = %s\n", (char *) mbi->cmdline);  /* @r{Are mods_* valid?} */  if (CHECK_FLAG (mbi->flags, 3))    @{      module_t *mod;      int i;            printf ("mods_count = %d, mods_addr = 0x%x\n",              (int) mbi->mods_count, (int) mbi->mods_addr);      for (i = 0, mod = (module_t *) mbi->mods_addr;           i < mbi->mods_count;           i++, mod += sizeof (module_t))        printf (" mod_start = 0x%x, mod_end = 0x%x, string = %s\n",                (unsigned) mod->mod_start,                (unsigned) mod->mod_end,                (char *) mod->string);    @}  /* @r{Bits 4 and 5 are mutually exclusive!} */  if (CHECK_FLAG (mbi->flags, 4) && CHECK_FLAG (mbi->flags, 5))    @{      printf ("Both bits 4 and 5 are set.\n");      return;    @}  /* @r{Is the symbol table of a.out valid?} */  if (CHECK_FLAG (mbi->flags, 4))    @{      aout_symbol_table_t *aout_sym = &(mbi->u.aout_sym);            printf ("aout_symbol_table: tabsize = 0x%0x, "              "strsize = 0x%x, addr = 0x%x\n",              (unsigned) aout_sym->tabsize,              (unsigned) aout_sym->strsize,              (unsigned) aout_sym->addr);    @}  /* @r{Is the section header table of ELF valid?} */  if (CHECK_FLAG (mbi->flags, 5))    @{      elf_section_header_table_t *elf_sec = &(mbi->u.elf_sec);      printf ("elf_sec: num = %u, size = 0x%x,"              " addr = 0x%x, shndx = 0x%x\n",              (unsigned) elf_sec->num, (unsigned) elf_sec->size,              (unsigned) elf_sec->addr, (unsigned) elf_sec->shndx);    @}  /* @r{Are mmap_* valid?} */  if (CHECK_FLAG (mbi->flags, 6))    @{      memory_map_t *mmap;            printf ("mmap_addr = 0x%x, mmap_length = 0x%x\n",              (unsigned) mbi->mmap_addr, (unsigned) mbi->mmap_length);      for (mmap = (memory_map_t *) mbi->mmap_addr;           (unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length;           mmap = (memory_map_t *) ((unsigned long) mmap                                    + mmap->size + sizeof (mmap->size)))        printf (" size = 0x%x, base_addr = 0x%x%x,"                " length = 0x%x%x, type = 0x%x\n",                (unsigned) mmap->size,                (unsigned) mmap->base_addr_high,                (unsigned) mmap->base_addr_low,                (unsigned) mmap->length_high,                (unsigned) mmap->length_low,                (unsigned) mmap->type);    @}@}    /* @r{Clear the screen and initialize VIDEO, XPOS and YPOS.} */static voidcls (void)@{  int i;  video = (unsigned char *) VIDEO;    for (i = 0; i < COLUMNS * LINES * 2; i++)    *(video + i) = 0;  xpos = 0;  ypos = 0;@}/* @r{Convert the integer D to a string and save the string in BUF. If   BASE is equal to 'd', interpret that D is decimal, and if BASE is   equal to 'x', interpret that D is hexadecimal.} */static voiditoa (char *buf, int base, int d)@{  char *p = buf;  char *p1, *p2;  unsigned long ud = d;  int divisor = 10;    /* @r{If %d is specified and D is minus, put `-' in the head.} */  if (base == 'd' && d < 0)    @{      *p++ = '-';      buf++;      ud = -d;    @}  else if (base == 'x')    divisor = 16;  /* @r{Divide UD by DIVISOR until UD == 0.} */  do    @{      int remainder = ud % divisor;            *p++ = (remainder < 10) ? remainder + '0' : remainder + 'a' - 10;    @}  while (ud /= divisor);  /* @r{Terminate BUF.} */  *p = 0;    /* @r{Reverse BUF.} */  p1 = buf;  p2 = p - 1;  while (p1 < p2)    @{      char tmp = *p1;      *p1 = *p2;      *p2 = tmp;      p1++;      p2--;    @}@}/* @r{Put the character C on the screen.} */static voidputchar (int c)@{  if (c == '\n' || c == '\r')    @{    newline:      xpos = 0;      ypos++;      if (ypos >= LINES)        ypos = 0;      return;    @}  *(video + (xpos + ypos * COLUMNS) * 2) = c & 0xFF;  *(video + (xpos + ypos * COLUMNS) * 2 + 1) = ATTRIBUTE;  xpos++;  if (xpos >= COLUMNS)    goto newline;@}/* @r{Format a string and print it on the screen, just like the libc   function printf.} */voidprintf (const char *format, ...)@{  char **arg = (char **) &format;  int c;  char buf[20];  arg++;    while ((c = *format++) != 0)    @{      if (c != '%')        putchar (c);      else        @{          char *p;                    c = *format++;          switch (c)            @{            case 'd':            case 'u':            case 'x':              itoa (buf, c, *((int *) arg++));              p = buf;              goto string;              break;            case 's':              p = *arg++;              if (! p)                p = "(null)";            string:              while (*p)                putchar (*p++);              break;            default:              putchar (*((int *) arg++));              break;            @}        @}    @}@}