minix/kernel/arch/i386/pre_init.c

   1
   2 #define UNPAGED 1       /* for proper kmain() prototype */
   3
   4 #include <assert.h>
   5 #include <stdlib.h>
   6 #include <minix/minlib.h>
   7 #include <minix/board.h>
   8 #include <sys/reboot.h>
   9 #include <machine/partition.h>
  10 #include "string.h"
  11 #include "direct_utils.h"
  12 #include "serial.h"
  13 #include "glo.h"
  14
  15 #if USE_SYSDEBUG
  16 #define MULTIBOOT_VERBOSE 1
  17 #endif
  18
  19 /* to-be-built kinfo struct, diagnostics buffer */
  20 kinfo_t kinfo;
  21 struct kmessages kmessages;
  22
  23 /* pg_utils.c uses this; in this phase, there is a 1:1 mapping. */
  24 phys_bytes vir2phys(void *addr) { return (phys_bytes) addr; }
  25
  26 /* mb_utils.c uses this; we can reach it directly */
  27 char *video_mem = (char *) MULTIBOOT_VIDEO_BUFFER;
  28
  29 /* String length used for mb_itoa */
  30 #define ITOA_BUFFER_SIZE 20
  31
  32 /* Kernel may use memory */
  33 int kernel_may_alloc = 1;
  34
  35 static int mb_set_param(char *bigbuf, char *name, char *value, kinfo_t *cbi)
  36 {
  37         char *p = bigbuf;
  38         char *bufend = bigbuf + MULTIBOOT_PARAM_BUF_SIZE;
  39         char *q;
  40         int namelen = strlen(name);
  41         int valuelen = strlen(value);
  42
  43         /* Some variables we recognize */
  44         if(!strcmp(name, SERVARNAME)) { cbi->do_serial_debug = 1; }
  45         if(!strcmp(name, SERBAUDVARNAME)) { cbi->serial_debug_baud = atoi(value); }
  46
  47         /* Delete the item if already exists */
  48         while (*p) {
  49                 if (strncmp(p, name, namelen) == 0 && p[namelen] == '=') {
  50                         q = p;
  51                         while (*q) q++;
  52                         for (q++; q < bufend; q++, p++)
  53                                 *p = *q;
  54                         break;
  55                 }
  56                 while (*p++)
  57                         ;
  58                 p++;
  59         }
  60
  61         for (p = bigbuf; p < bufend && (*p || *(p + 1)); p++)
  62                 ;
  63         if (p > bigbuf) p++;
  64
  65         /* Make sure there's enough space for the new parameter */
  66         if (p + namelen + valuelen + 3 > bufend)
  67                 return -1;
  68
  69         strcpy(p, name);
  70         p[namelen] = '=';
  71         strcpy(p + namelen + 1, value);
  72         p[namelen + valuelen + 1] = 0;
  73         p[namelen + valuelen + 2] = 0;
  74         return 0;
  75 }
  76
  77 int overlaps(multiboot_module_t *mod, int n, int cmp_mod)
  78 {
  79         multiboot_module_t *cmp = &mod[cmp_mod];
  80         int m;
  81
  82 #define INRANGE(mod, v) ((v) >= mod->mod_start && (v) < mod->mod_end)
  83 #define OVERLAP(mod1, mod2) (INRANGE(mod1, mod2->mod_start) || \
  84                         INRANGE(mod1, mod2->mod_end-1))
  85         for(m = 0; m < n; m++) {
  86                 multiboot_module_t *thismod = &mod[m];
  87                 if(m == cmp_mod) continue;
  88                 if(OVERLAP(thismod, cmp))
  89                         return 1;
  90         }
  91         return 0;
  92 }
  93
  94 void get_parameters(u32_t ebx, kinfo_t *cbi)
  95 {
  96         multiboot_memory_map_t *mmap;
  97         multiboot_info_t *mbi = &cbi->mbi;
  98         int var_i,value_i, m, k;
  99         char *p;
 100         extern char _kern_phys_base, _kern_vir_base, _kern_size,
 101                 _kern_unpaged_start, _kern_unpaged_end;
 102         phys_bytes kernbase = (phys_bytes) &_kern_phys_base,
 103                 kernsize = (phys_bytes) &_kern_size;
 104 #define BUF 1024
 105         static char cmdline[BUF];
 106
 107         /* get our own copy of the multiboot info struct and module list */
 108         memcpy((void *) mbi, (void *) ebx, sizeof(*mbi));
 109
 110         /* Set various bits of info for the higher-level kernel. */
 111         cbi->mem_high_phys = 0;
 112         cbi->user_sp = (vir_bytes) &_kern_vir_base;
 113         cbi->vir_kern_start = (vir_bytes) &_kern_vir_base;
 114         cbi->bootstrap_start = (vir_bytes) &_kern_unpaged_start;
 115         cbi->bootstrap_len = (vir_bytes) &_kern_unpaged_end -
 116                 cbi->bootstrap_start;
 117         cbi->kmess = &kmess;
 118
 119         /* set some configurable defaults */
 120         cbi->do_serial_debug = 0;
 121         cbi->serial_debug_baud = 115200;
 122
 123         /* parse boot command line */
 124         if (mbi->mi_flags & MULTIBOOT_INFO_HAS_CMDLINE) {
 125                 static char var[BUF];
 126                 static char value[BUF];
 127
 128                 /* Override values with cmdline argument */
 129                 memcpy(cmdline, (void *) mbi->mi_cmdline, BUF);
 130                 p = cmdline;
 131                 while (*p) {
 132                         var_i = 0;
 133                         value_i = 0;
 134                         while (*p == ' ') p++;
 135                         if (!*p) break;
 136                         while (*p && *p != '=' && *p != ' ' && var_i < BUF - 1)
 137                                 var[var_i++] = *p++ ;
 138                         var[var_i] = 0;
 139                         if (*p++ != '=') continue; /* skip if not name=value */
 140                         while (*p && *p != ' ' && value_i < BUF - 1)
 141                                 value[value_i++] = *p++ ;
 142                         value[value_i] = 0;
 143
 144                         mb_set_param(cbi->param_buf, var, value, cbi);
 145                 }
 146         }
 147
 148         /* let higher levels know what we are booting on */
 149         mb_set_param(cbi->param_buf, ARCHVARNAME, (char *)get_board_arch_name(BOARD_ID_INTEL), cbi);
 150         mb_set_param(cbi->param_buf, BOARDVARNAME,(char *)get_board_name(BOARD_ID_INTEL) , cbi);
 151
 152         /* move user stack/data down to leave a gap to catch kernel
 153          * stack overflow; and to distinguish kernel and user addresses
 154          * at a glance (0xf.. vs 0xe..)
 155          */
 156         cbi->user_sp = USR_STACKTOP;
 157         cbi->user_end = USR_DATATOP;
 158
 159         /* kernel bytes without bootstrap code/data that is currently
 160          * still needed but will be freed after bootstrapping.
 161          */
 162         kinfo.kernel_allocated_bytes = (phys_bytes) &_kern_size;
 163         kinfo.kernel_allocated_bytes -= cbi->bootstrap_len;
 164
 165         assert(!(cbi->bootstrap_start % I386_PAGE_SIZE));
 166         cbi->bootstrap_len = rounddown(cbi->bootstrap_len, I386_PAGE_SIZE);
 167         assert(mbi->mi_flags & MULTIBOOT_INFO_HAS_MODS);
 168         assert(mbi->mi_mods_count < MULTIBOOT_MAX_MODS);
 169         assert(mbi->mi_mods_count > 0);
 170         memcpy(&cbi->module_list, (void *) mbi->mi_mods_addr,
 171                 mbi->mi_mods_count * sizeof(multiboot_module_t));
 172
 173         memset(cbi->memmap, 0, sizeof(cbi->memmap));
 174         /* mem_map has a variable layout */
 175         if(mbi->mi_flags & MULTIBOOT_INFO_HAS_MMAP) {
 176                 cbi->mmap_size = 0;
 177                 for (mmap = (multiboot_memory_map_t *) mbi->mmap_addr;
 178              (unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length;
 179                mmap = (multiboot_memory_map_t *)
 180                         ((unsigned long) mmap + mmap->mm_size + sizeof(mmap->mm_size))) {
 181                         if(mmap->mm_type != MULTIBOOT_MEMORY_AVAILABLE) continue;
 182                         add_memmap(cbi, mmap->mm_base_addr, mmap->mm_length);
 183                 }
 184         } else {
 185                 assert(mbi->mi_flags & MULTIBOOT_INFO_HAS_MEMORY);
 186                 add_memmap(cbi, 0, mbi->mi_mem_lower*1024);
 187                 add_memmap(cbi, 0x100000, mbi->mi_mem_upper*1024);
 188         }
 189
 190         /* Sanity check: the kernel nor any of the modules may overlap
 191          * with each other. Pretend the kernel is an extra module for a
 192          * second.
 193          */
 194         k = mbi->mi_mods_count;
 195         assert(k < MULTIBOOT_MAX_MODS);
 196         cbi->module_list[k].mod_start = kernbase;
 197         cbi->module_list[k].mod_end = kernbase + kernsize;
 198         cbi->mods_with_kernel = mbi->mi_mods_count+1;
 199         cbi->kern_mod = k;
 200
 201         for(m = 0; m < cbi->mods_with_kernel; m++) {
 202 #if 0
 203                 printf("checking overlap of module %08lx-%08lx\n",
 204                   cbi->module_list[m].mod_start, cbi->module_list[m].mod_end);
 205 #endif
 206                 if(overlaps(cbi->module_list, cbi->mods_with_kernel, m))
 207                         panic("overlapping boot modules/kernel");
 208                 /* We cut out the bits of memory that we know are
 209                  * occupied by the kernel and boot modules.
 210                  */
 211                 cut_memmap(cbi,
 212                         cbi->module_list[m].mod_start,
 213                         cbi->module_list[m].mod_end);
 214         }
 215 }
 216
 217 kinfo_t *pre_init(u32_t magic, u32_t ebx)
 218 {
 219         assert(magic == MULTIBOOT_INFO_MAGIC);
 220
 221         /* Get our own copy boot params pointed to by ebx.
 222          * Here we find out whether we should do serial output.
 223          */
 224         get_parameters(ebx, &kinfo);
 225
 226         /* Make and load a pagetable that will map the kernel
 227          * to where it should be; but first a 1:1 mapping so
 228          * this code stays where it should be.
 229          */
 230         pg_clear();
 231         pg_identity(&kinfo);
 232         kinfo.freepde_start = pg_mapkernel();
 233         pg_load();
 234         vm_enable_paging();
 235
 236         /* Done, return boot info so it can be passed to kmain(). */
 237         return &kinfo;
 238 }
 239
 240 void send_diag_sig(void) { }
 241 void minix_shutdown(int how) { arch_shutdown(how); }
 242 void busy_delay_ms(int x) { }
 243 int raise(int sig) { panic("raise(%d)\n", sig); }