kernel.c.texi revision 1b8adde7ba7d5e04395c141c5400dc2cffd7d809
/* @r{kernel.c - the C part of the kernel} */
/* @r{Copyright (C) 1999 Free Software Foundation, Inc.
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.} */
/* @r{Macros.} */
/* @r{Check if the bit BIT in FLAGS is set.} */
/* @r{Some screen stuff.} */
/* @r{The number of columns.} */
/* @r{The number of lines.} */
/* @r{The attribute of an character.} */
/* @r{The video memory address.} */
/* @r{Variables.} */
/* @r{Save the X position.} */
static int xpos;
/* @r{Save the Y position.} */
static int ypos;
/* @r{Point to the video memory.} */
/* @r{Forward declarations.} */
static void cls (void);
static void putchar (int c);
/* @r{Check if MAGIC is valid and print the Multiboot information structure
pointed by ADDR.} */
void
@{
/* @r{Clear the screen.} */
cls ();
/* @r{Am I booted by a Multiboot-compliant boot loader?} */
if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
@{
return;
@}
/* @r{Set MBI to the address of the Multiboot information structure.} */
/* @r{Print out the flags.} */
/* @r{Are mem_* valid?} */
printf ("mem_lower = %uKB, mem_upper = %uKB\n",
/* @r{Is boot_device valid?} */
/* @r{Is the command line passed?} */
/* @r{Are mods_* valid?} */
@{
int i;
printf ("mods_count = %d, mods_addr = 0x%x\n",
i < mbi->mods_count;
i++, mod++)
printf (" mod_start = 0x%x, mod_end = 0x%x, string = %s\n",
@}
/* @r{Bits 4 and 5 are mutually exclusive!} */
@{
printf ("Both bits 4 and 5 are set.\n");
return;
@}
/* @r{Is the symbol table of a.out valid?} */
@{
printf ("aout_symbol_table: tabsize = 0x%0x, "
"strsize = 0x%x, addr = 0x%x\n",
@}
/* @r{Is the section header table of ELF valid?} */
@{
printf ("elf_sec: num = %u, size = 0x%x,"
" addr = 0x%x, shndx = 0x%x\n",
@}
/* @r{Are mmap_* valid?} */
@{
printf ("mmap_addr = 0x%x, mmap_length = 0x%x\n",
printf (" size = 0x%x, base_addr = 0x%x%x,"
" length = 0x%x%x, type = 0x%x\n",
@}
@}
/* @r{Clear the screen and initialize VIDEO, XPOS and YPOS.} */
static void
cls (void)
@{
int 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 void
@{
char *p = buf;
int divisor = 10;
/* @r{If %d is specified and D is minus, put `-' in the head.} */
@{
*p++ = '-';
buf++;
ud = -d;
@}
else if (base == 'x')
divisor = 16;
/* @r{Divide UD by DIVISOR until UD == 0.} */
do
@{
@}
/* @r{Terminate BUF.} */
*p = 0;
/* @r{Reverse BUF.} */
p2 = p - 1;
@{
p1++;
p2--;
@}
@}
/* @r{Put the character C on the screen.} */
static void
putchar (int c)
@{
if (c == '\n' || c == '\r')
@{
xpos = 0;
ypos++;
ypos = 0;
return;
@}
xpos++;
goto newline;
@}
/* @r{Format a string and print it on the screen, just like the libc
function printf.} */
void
@{
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':
p = buf;
goto string;
break;
case 's':
p = *arg++;
if (! p)
p = "(null)";
while (*p)
putchar (*p++);
break;
default:
break;
@}
@}
@}
@}