xref: /onnv-gate/usr/src/grub/grub-0.97/docs/kernel.c (revision 8044:b3af80bbf173)
1*8044SWilliam.Kucharski@Sun.COM /* kernel.c - the C part of the kernel */
2*8044SWilliam.Kucharski@Sun.COM /* Copyright (C) 1999  Free Software Foundation, Inc.
3*8044SWilliam.Kucharski@Sun.COM 
4*8044SWilliam.Kucharski@Sun.COM    This program is free software; you can redistribute it and/or modify
5*8044SWilliam.Kucharski@Sun.COM    it under the terms of the GNU General Public License as published by
6*8044SWilliam.Kucharski@Sun.COM    the Free Software Foundation; either version 2 of the License, or
7*8044SWilliam.Kucharski@Sun.COM    (at your option) any later version.
8*8044SWilliam.Kucharski@Sun.COM 
9*8044SWilliam.Kucharski@Sun.COM    This program is distributed in the hope that it will be useful,
10*8044SWilliam.Kucharski@Sun.COM    but WITHOUT ANY WARRANTY; without even the implied warranty of
11*8044SWilliam.Kucharski@Sun.COM    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12*8044SWilliam.Kucharski@Sun.COM    GNU General Public License for more details.
13*8044SWilliam.Kucharski@Sun.COM 
14*8044SWilliam.Kucharski@Sun.COM    You should have received a copy of the GNU General Public License
15*8044SWilliam.Kucharski@Sun.COM    along with this program; if not, write to the Free Software
16*8044SWilliam.Kucharski@Sun.COM    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
17*8044SWilliam.Kucharski@Sun.COM 
18*8044SWilliam.Kucharski@Sun.COM #include <multiboot.h>
19*8044SWilliam.Kucharski@Sun.COM 
20*8044SWilliam.Kucharski@Sun.COM /* Macros.  */
21*8044SWilliam.Kucharski@Sun.COM 
22*8044SWilliam.Kucharski@Sun.COM /* Check if the bit BIT in FLAGS is set.  */
23*8044SWilliam.Kucharski@Sun.COM #define CHECK_FLAG(flags,bit)	((flags) & (1 << (bit)))
24*8044SWilliam.Kucharski@Sun.COM 
25*8044SWilliam.Kucharski@Sun.COM /* Some screen stuff.  */
26*8044SWilliam.Kucharski@Sun.COM /* The number of columns.  */
27*8044SWilliam.Kucharski@Sun.COM #define COLUMNS			80
28*8044SWilliam.Kucharski@Sun.COM /* The number of lines.  */
29*8044SWilliam.Kucharski@Sun.COM #define LINES			24
30*8044SWilliam.Kucharski@Sun.COM /* The attribute of an character.  */
31*8044SWilliam.Kucharski@Sun.COM #define ATTRIBUTE		7
32*8044SWilliam.Kucharski@Sun.COM /* The video memory address.  */
33*8044SWilliam.Kucharski@Sun.COM #define VIDEO			0xB8000
34*8044SWilliam.Kucharski@Sun.COM 
35*8044SWilliam.Kucharski@Sun.COM /* Variables.  */
36*8044SWilliam.Kucharski@Sun.COM /* Save the X position.  */
37*8044SWilliam.Kucharski@Sun.COM static int xpos;
38*8044SWilliam.Kucharski@Sun.COM /* Save the Y position.  */
39*8044SWilliam.Kucharski@Sun.COM static int ypos;
40*8044SWilliam.Kucharski@Sun.COM /* Point to the video memory.  */
41*8044SWilliam.Kucharski@Sun.COM static volatile unsigned char *video;
42*8044SWilliam.Kucharski@Sun.COM 
43*8044SWilliam.Kucharski@Sun.COM /* Forward declarations.  */
44*8044SWilliam.Kucharski@Sun.COM void cmain (unsigned long magic, unsigned long addr);
45*8044SWilliam.Kucharski@Sun.COM static void cls (void);
46*8044SWilliam.Kucharski@Sun.COM static void itoa (char *buf, int base, int d);
47*8044SWilliam.Kucharski@Sun.COM static void putchar (int c);
48*8044SWilliam.Kucharski@Sun.COM void printf (const char *format, ...);
49*8044SWilliam.Kucharski@Sun.COM 
50*8044SWilliam.Kucharski@Sun.COM /* Check if MAGIC is valid and print the Multiboot information structure
51*8044SWilliam.Kucharski@Sun.COM    pointed by ADDR.  */
52*8044SWilliam.Kucharski@Sun.COM void
cmain(unsigned long magic,unsigned long addr)53*8044SWilliam.Kucharski@Sun.COM cmain (unsigned long magic, unsigned long addr)
54*8044SWilliam.Kucharski@Sun.COM {
55*8044SWilliam.Kucharski@Sun.COM   multiboot_info_t *mbi;
56*8044SWilliam.Kucharski@Sun.COM 
57*8044SWilliam.Kucharski@Sun.COM   /* Clear the screen.  */
58*8044SWilliam.Kucharski@Sun.COM   cls ();
59*8044SWilliam.Kucharski@Sun.COM 
60*8044SWilliam.Kucharski@Sun.COM   /* Am I booted by a Multiboot-compliant boot loader?  */
61*8044SWilliam.Kucharski@Sun.COM   if (magic != MULTIBOOT_BOOTLOADER_MAGIC)
62*8044SWilliam.Kucharski@Sun.COM     {
63*8044SWilliam.Kucharski@Sun.COM       printf ("Invalid magic number: 0x%x\n", (unsigned) magic);
64*8044SWilliam.Kucharski@Sun.COM       return;
65*8044SWilliam.Kucharski@Sun.COM     }
66*8044SWilliam.Kucharski@Sun.COM 
67*8044SWilliam.Kucharski@Sun.COM   /* Set MBI to the address of the Multiboot information structure.  */
68*8044SWilliam.Kucharski@Sun.COM   mbi = (multiboot_info_t *) addr;
69*8044SWilliam.Kucharski@Sun.COM 
70*8044SWilliam.Kucharski@Sun.COM   /* Print out the flags.  */
71*8044SWilliam.Kucharski@Sun.COM   printf ("flags = 0x%x\n", (unsigned) mbi->flags);
72*8044SWilliam.Kucharski@Sun.COM 
73*8044SWilliam.Kucharski@Sun.COM   /* Are mem_* valid?  */
74*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 0))
75*8044SWilliam.Kucharski@Sun.COM     printf ("mem_lower = %uKB, mem_upper = %uKB\n",
76*8044SWilliam.Kucharski@Sun.COM 	    (unsigned) mbi->mem_lower, (unsigned) mbi->mem_upper);
77*8044SWilliam.Kucharski@Sun.COM 
78*8044SWilliam.Kucharski@Sun.COM   /* Is boot_device valid?  */
79*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 1))
80*8044SWilliam.Kucharski@Sun.COM     printf ("boot_device = 0x%x\n", (unsigned) mbi->boot_device);
81*8044SWilliam.Kucharski@Sun.COM 
82*8044SWilliam.Kucharski@Sun.COM   /* Is the command line passed?  */
83*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 2))
84*8044SWilliam.Kucharski@Sun.COM     printf ("cmdline = %s\n", (char *) mbi->cmdline);
85*8044SWilliam.Kucharski@Sun.COM 
86*8044SWilliam.Kucharski@Sun.COM   /* Are mods_* valid?  */
87*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 3))
88*8044SWilliam.Kucharski@Sun.COM     {
89*8044SWilliam.Kucharski@Sun.COM       module_t *mod;
90*8044SWilliam.Kucharski@Sun.COM       int i;
91*8044SWilliam.Kucharski@Sun.COM 
92*8044SWilliam.Kucharski@Sun.COM       printf ("mods_count = %d, mods_addr = 0x%x\n",
93*8044SWilliam.Kucharski@Sun.COM 	      (int) mbi->mods_count, (int) mbi->mods_addr);
94*8044SWilliam.Kucharski@Sun.COM       for (i = 0, mod = (module_t *) mbi->mods_addr;
95*8044SWilliam.Kucharski@Sun.COM 	   i < mbi->mods_count;
96*8044SWilliam.Kucharski@Sun.COM 	   i++, mod++)
97*8044SWilliam.Kucharski@Sun.COM 	printf (" mod_start = 0x%x, mod_end = 0x%x, string = %s\n",
98*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mod->mod_start,
99*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mod->mod_end,
100*8044SWilliam.Kucharski@Sun.COM 		(char *) mod->string);
101*8044SWilliam.Kucharski@Sun.COM     }
102*8044SWilliam.Kucharski@Sun.COM 
103*8044SWilliam.Kucharski@Sun.COM   /* Bits 4 and 5 are mutually exclusive!  */
104*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 4) && CHECK_FLAG (mbi->flags, 5))
105*8044SWilliam.Kucharski@Sun.COM     {
106*8044SWilliam.Kucharski@Sun.COM       printf ("Both bits 4 and 5 are set.\n");
107*8044SWilliam.Kucharski@Sun.COM       return;
108*8044SWilliam.Kucharski@Sun.COM     }
109*8044SWilliam.Kucharski@Sun.COM 
110*8044SWilliam.Kucharski@Sun.COM   /* Is the symbol table of a.out valid?  */
111*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 4))
112*8044SWilliam.Kucharski@Sun.COM     {
113*8044SWilliam.Kucharski@Sun.COM       aout_symbol_table_t *aout_sym = &(mbi->u.aout_sym);
114*8044SWilliam.Kucharski@Sun.COM 
115*8044SWilliam.Kucharski@Sun.COM       printf ("aout_symbol_table: tabsize = 0x%0x, "
116*8044SWilliam.Kucharski@Sun.COM 	      "strsize = 0x%x, addr = 0x%x\n",
117*8044SWilliam.Kucharski@Sun.COM 	      (unsigned) aout_sym->tabsize,
118*8044SWilliam.Kucharski@Sun.COM 	      (unsigned) aout_sym->strsize,
119*8044SWilliam.Kucharski@Sun.COM 	      (unsigned) aout_sym->addr);
120*8044SWilliam.Kucharski@Sun.COM     }
121*8044SWilliam.Kucharski@Sun.COM 
122*8044SWilliam.Kucharski@Sun.COM   /* Is the section header table of ELF valid?  */
123*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 5))
124*8044SWilliam.Kucharski@Sun.COM     {
125*8044SWilliam.Kucharski@Sun.COM       elf_section_header_table_t *elf_sec = &(mbi->u.elf_sec);
126*8044SWilliam.Kucharski@Sun.COM 
127*8044SWilliam.Kucharski@Sun.COM       printf ("elf_sec: num = %u, size = 0x%x,"
128*8044SWilliam.Kucharski@Sun.COM 	      " addr = 0x%x, shndx = 0x%x\n",
129*8044SWilliam.Kucharski@Sun.COM 	      (unsigned) elf_sec->num, (unsigned) elf_sec->size,
130*8044SWilliam.Kucharski@Sun.COM 	      (unsigned) elf_sec->addr, (unsigned) elf_sec->shndx);
131*8044SWilliam.Kucharski@Sun.COM     }
132*8044SWilliam.Kucharski@Sun.COM 
133*8044SWilliam.Kucharski@Sun.COM   /* Are mmap_* valid?  */
134*8044SWilliam.Kucharski@Sun.COM   if (CHECK_FLAG (mbi->flags, 6))
135*8044SWilliam.Kucharski@Sun.COM     {
136*8044SWilliam.Kucharski@Sun.COM       memory_map_t *mmap;
137*8044SWilliam.Kucharski@Sun.COM 
138*8044SWilliam.Kucharski@Sun.COM       printf ("mmap_addr = 0x%x, mmap_length = 0x%x\n",
139*8044SWilliam.Kucharski@Sun.COM 	      (unsigned) mbi->mmap_addr, (unsigned) mbi->mmap_length);
140*8044SWilliam.Kucharski@Sun.COM       for (mmap = (memory_map_t *) mbi->mmap_addr;
141*8044SWilliam.Kucharski@Sun.COM 	   (unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length;
142*8044SWilliam.Kucharski@Sun.COM 	   mmap = (memory_map_t *) ((unsigned long) mmap
143*8044SWilliam.Kucharski@Sun.COM 				    + mmap->size + sizeof (mmap->size)))
144*8044SWilliam.Kucharski@Sun.COM 	printf (" size = 0x%x, base_addr = 0x%x%x,"
145*8044SWilliam.Kucharski@Sun.COM 		" length = 0x%x%x, type = 0x%x\n",
146*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mmap->size,
147*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mmap->base_addr_high,
148*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mmap->base_addr_low,
149*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mmap->length_high,
150*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mmap->length_low,
151*8044SWilliam.Kucharski@Sun.COM 		(unsigned) mmap->type);
152*8044SWilliam.Kucharski@Sun.COM     }
153*8044SWilliam.Kucharski@Sun.COM }
154*8044SWilliam.Kucharski@Sun.COM 
155*8044SWilliam.Kucharski@Sun.COM /* Clear the screen and initialize VIDEO, XPOS and YPOS.  */
156*8044SWilliam.Kucharski@Sun.COM static void
cls(void)157*8044SWilliam.Kucharski@Sun.COM cls (void)
158*8044SWilliam.Kucharski@Sun.COM {
159*8044SWilliam.Kucharski@Sun.COM   int i;
160*8044SWilliam.Kucharski@Sun.COM 
161*8044SWilliam.Kucharski@Sun.COM   video = (unsigned char *) VIDEO;
162*8044SWilliam.Kucharski@Sun.COM 
163*8044SWilliam.Kucharski@Sun.COM   for (i = 0; i < COLUMNS * LINES * 2; i++)
164*8044SWilliam.Kucharski@Sun.COM     *(video + i) = 0;
165*8044SWilliam.Kucharski@Sun.COM 
166*8044SWilliam.Kucharski@Sun.COM   xpos = 0;
167*8044SWilliam.Kucharski@Sun.COM   ypos = 0;
168*8044SWilliam.Kucharski@Sun.COM }
169*8044SWilliam.Kucharski@Sun.COM 
170*8044SWilliam.Kucharski@Sun.COM /* Convert the integer D to a string and save the string in BUF. If
171*8044SWilliam.Kucharski@Sun.COM    BASE is equal to 'd', interpret that D is decimal, and if BASE is
172*8044SWilliam.Kucharski@Sun.COM    equal to 'x', interpret that D is hexadecimal.  */
173*8044SWilliam.Kucharski@Sun.COM static void
itoa(char * buf,int base,int d)174*8044SWilliam.Kucharski@Sun.COM itoa (char *buf, int base, int d)
175*8044SWilliam.Kucharski@Sun.COM {
176*8044SWilliam.Kucharski@Sun.COM   char *p = buf;
177*8044SWilliam.Kucharski@Sun.COM   char *p1, *p2;
178*8044SWilliam.Kucharski@Sun.COM   unsigned long ud = d;
179*8044SWilliam.Kucharski@Sun.COM   int divisor = 10;
180*8044SWilliam.Kucharski@Sun.COM 
181*8044SWilliam.Kucharski@Sun.COM   /* If %d is specified and D is minus, put `-' in the head.  */
182*8044SWilliam.Kucharski@Sun.COM   if (base == 'd' && d < 0)
183*8044SWilliam.Kucharski@Sun.COM     {
184*8044SWilliam.Kucharski@Sun.COM       *p++ = '-';
185*8044SWilliam.Kucharski@Sun.COM       buf++;
186*8044SWilliam.Kucharski@Sun.COM       ud = -d;
187*8044SWilliam.Kucharski@Sun.COM     }
188*8044SWilliam.Kucharski@Sun.COM   else if (base == 'x')
189*8044SWilliam.Kucharski@Sun.COM     divisor = 16;
190*8044SWilliam.Kucharski@Sun.COM 
191*8044SWilliam.Kucharski@Sun.COM   /* Divide UD by DIVISOR until UD == 0.  */
192*8044SWilliam.Kucharski@Sun.COM   do
193*8044SWilliam.Kucharski@Sun.COM     {
194*8044SWilliam.Kucharski@Sun.COM       int remainder = ud % divisor;
195*8044SWilliam.Kucharski@Sun.COM 
196*8044SWilliam.Kucharski@Sun.COM       *p++ = (remainder < 10) ? remainder + '0' : remainder + 'a' - 10;
197*8044SWilliam.Kucharski@Sun.COM     }
198*8044SWilliam.Kucharski@Sun.COM   while (ud /= divisor);
199*8044SWilliam.Kucharski@Sun.COM 
200*8044SWilliam.Kucharski@Sun.COM   /* Terminate BUF.  */
201*8044SWilliam.Kucharski@Sun.COM   *p = 0;
202*8044SWilliam.Kucharski@Sun.COM 
203*8044SWilliam.Kucharski@Sun.COM   /* Reverse BUF.  */
204*8044SWilliam.Kucharski@Sun.COM   p1 = buf;
205*8044SWilliam.Kucharski@Sun.COM   p2 = p - 1;
206*8044SWilliam.Kucharski@Sun.COM   while (p1 < p2)
207*8044SWilliam.Kucharski@Sun.COM     {
208*8044SWilliam.Kucharski@Sun.COM       char tmp = *p1;
209*8044SWilliam.Kucharski@Sun.COM       *p1 = *p2;
210*8044SWilliam.Kucharski@Sun.COM       *p2 = tmp;
211*8044SWilliam.Kucharski@Sun.COM       p1++;
212*8044SWilliam.Kucharski@Sun.COM       p2--;
213*8044SWilliam.Kucharski@Sun.COM     }
214*8044SWilliam.Kucharski@Sun.COM }
215*8044SWilliam.Kucharski@Sun.COM 
216*8044SWilliam.Kucharski@Sun.COM /* Put the character C on the screen.  */
217*8044SWilliam.Kucharski@Sun.COM static void
putchar(int c)218*8044SWilliam.Kucharski@Sun.COM putchar (int c)
219*8044SWilliam.Kucharski@Sun.COM {
220*8044SWilliam.Kucharski@Sun.COM   if (c == '\n' || c == '\r')
221*8044SWilliam.Kucharski@Sun.COM     {
222*8044SWilliam.Kucharski@Sun.COM     newline:
223*8044SWilliam.Kucharski@Sun.COM       xpos = 0;
224*8044SWilliam.Kucharski@Sun.COM       ypos++;
225*8044SWilliam.Kucharski@Sun.COM       if (ypos >= LINES)
226*8044SWilliam.Kucharski@Sun.COM 	ypos = 0;
227*8044SWilliam.Kucharski@Sun.COM       return;
228*8044SWilliam.Kucharski@Sun.COM     }
229*8044SWilliam.Kucharski@Sun.COM 
230*8044SWilliam.Kucharski@Sun.COM   *(video + (xpos + ypos * COLUMNS) * 2) = c & 0xFF;
231*8044SWilliam.Kucharski@Sun.COM   *(video + (xpos + ypos * COLUMNS) * 2 + 1) = ATTRIBUTE;
232*8044SWilliam.Kucharski@Sun.COM 
233*8044SWilliam.Kucharski@Sun.COM   xpos++;
234*8044SWilliam.Kucharski@Sun.COM   if (xpos >= COLUMNS)
235*8044SWilliam.Kucharski@Sun.COM     goto newline;
236*8044SWilliam.Kucharski@Sun.COM }
237*8044SWilliam.Kucharski@Sun.COM 
238*8044SWilliam.Kucharski@Sun.COM /* Format a string and print it on the screen, just like the libc
239*8044SWilliam.Kucharski@Sun.COM    function printf.  */
240*8044SWilliam.Kucharski@Sun.COM void
printf(const char * format,...)241*8044SWilliam.Kucharski@Sun.COM printf (const char *format, ...)
242*8044SWilliam.Kucharski@Sun.COM {
243*8044SWilliam.Kucharski@Sun.COM   char **arg = (char **) &format;
244*8044SWilliam.Kucharski@Sun.COM   int c;
245*8044SWilliam.Kucharski@Sun.COM   char buf[20];
246*8044SWilliam.Kucharski@Sun.COM 
247*8044SWilliam.Kucharski@Sun.COM   arg++;
248*8044SWilliam.Kucharski@Sun.COM 
249*8044SWilliam.Kucharski@Sun.COM   while ((c = *format++) != 0)
250*8044SWilliam.Kucharski@Sun.COM     {
251*8044SWilliam.Kucharski@Sun.COM       if (c != '%')
252*8044SWilliam.Kucharski@Sun.COM 	putchar (c);
253*8044SWilliam.Kucharski@Sun.COM       else
254*8044SWilliam.Kucharski@Sun.COM 	{
255*8044SWilliam.Kucharski@Sun.COM 	  char *p;
256*8044SWilliam.Kucharski@Sun.COM 
257*8044SWilliam.Kucharski@Sun.COM 	  c = *format++;
258*8044SWilliam.Kucharski@Sun.COM 	  switch (c)
259*8044SWilliam.Kucharski@Sun.COM 	    {
260*8044SWilliam.Kucharski@Sun.COM 	    case 'd':
261*8044SWilliam.Kucharski@Sun.COM 	    case 'u':
262*8044SWilliam.Kucharski@Sun.COM 	    case 'x':
263*8044SWilliam.Kucharski@Sun.COM 	      itoa (buf, c, *((int *) arg++));
264*8044SWilliam.Kucharski@Sun.COM 	      p = buf;
265*8044SWilliam.Kucharski@Sun.COM 	      goto string;
266*8044SWilliam.Kucharski@Sun.COM 	      break;
267*8044SWilliam.Kucharski@Sun.COM 
268*8044SWilliam.Kucharski@Sun.COM 	    case 's':
269*8044SWilliam.Kucharski@Sun.COM 	      p = *arg++;
270*8044SWilliam.Kucharski@Sun.COM 	      if (! p)
271*8044SWilliam.Kucharski@Sun.COM 		p = "(null)";
272*8044SWilliam.Kucharski@Sun.COM 
273*8044SWilliam.Kucharski@Sun.COM 	    string:
274*8044SWilliam.Kucharski@Sun.COM 	      while (*p)
275*8044SWilliam.Kucharski@Sun.COM 		putchar (*p++);
276*8044SWilliam.Kucharski@Sun.COM 	      break;
277*8044SWilliam.Kucharski@Sun.COM 
278*8044SWilliam.Kucharski@Sun.COM 	    default:
279*8044SWilliam.Kucharski@Sun.COM 	      putchar (*((int *) arg++));
280*8044SWilliam.Kucharski@Sun.COM 	      break;
281*8044SWilliam.Kucharski@Sun.COM 	    }
282*8044SWilliam.Kucharski@Sun.COM 	}
283*8044SWilliam.Kucharski@Sun.COM     }
284*8044SWilliam.Kucharski@Sun.COM }
285