kernel/arch/i386/pre_init.c

   1
   2 #define UNPAGED 1       /* for proper kmain() prototype */
   3
   4 #include "kernel.h"
   5 #include <assert.h>
   6 #include <stdlib.h>
   7 #include <minix/minlib.h>
   8 #include <minix/const.h>
   9 #include <minix/types.h>
  10 #include <minix/type.h>
  11 #include <minix/com.h>
  12 #include <sys/param.h>
  13 #include <sys/reboot.h>
  14 #include <machine/partition.h>
  15 #include "string.h"
  16 #include "arch_proto.h"
  17 #include "libexec.h"
  18 #include "direct_utils.h"
  19 #include "serial.h"
  20 #include "glo.h"
  21 #include <machine/multiboot.h>
  22
  23 #if USE_SYSDEBUG
  24 #define MULTIBOOT_VERBOSE 1
  25 #endif
  26
  27 /* to-be-built kinfo struct, diagnostics buffer */
  28 kinfo_t kinfo;
  29 struct kmessages kmessages;
  30
  31 /* pg_utils.c uses this; in this phase, there is a 1:1 mapping. */
  32 phys_bytes vir2phys(void *addr) { return (phys_bytes) addr; }
  33
  34 /* mb_utils.c uses this; we can reach it directly */
  35 char *video_mem = (char *) MULTIBOOT_VIDEO_BUFFER;
  36
  37 /* String length used for mb_itoa */
  38 #define ITOA_BUFFER_SIZE 20
  39
  40 /* Kernel may use memory */
  41 int kernel_may_alloc = 1;
  42
  43 static int mb_set_param(char *bigbuf, char *name, char *value, kinfo_t *cbi)
  44 {
  45         char *p = bigbuf;
  46         char *bufend = bigbuf + MULTIBOOT_PARAM_BUF_SIZE;
  47         char *q;
  48         int namelen = strlen(name);
  49         int valuelen = strlen(value);
  50
  51         /* Some variables we recognize */
  52         if(!strcmp(name, SERVARNAME)) { cbi->do_serial_debug = 1; }
  53         if(!strcmp(name, SERBAUDVARNAME)) { cbi->serial_debug_baud = atoi(value); }
  54
  55         /* Delete the item if already exists */
  56         while (*p) {
  57                 if (strncmp(p, name, namelen) == 0 && p[namelen] == '=') {
  58                         q = p;
  59                         while (*q) q++;
  60                         for (q++; q < bufend; q++, p++)
  61                                 *p = *q;
  62                         break;
  63                 }
  64                 while (*p++)
  65                         ;
  66                 p++;
  67         }
  68
  69         for (p = bigbuf; p < bufend && (*p || *(p + 1)); p++)
  70                 ;
  71         if (p > bigbuf) p++;
  72
  73         /* Make sure there's enough space for the new parameter */
  74         if (p + namelen + valuelen + 3 > bufend)
  75                 return -1;
  76
  77         strcpy(p, name);
  78         p[namelen] = '=';
  79         strcpy(p + namelen + 1, value);
  80         p[namelen + valuelen + 1] = 0;
  81         p[namelen + valuelen + 2] = 0;
  82         return 0;
  83 }
  84
  85 int overlaps(multiboot_module_t *mod, int n, int cmp_mod)
  86 {
  87         multiboot_module_t *cmp = &mod[cmp_mod];
  88         int m;
  89
  90 #define INRANGE(mod, v) ((v) >= mod->mod_start && (v) <= thismod->mod_end)
  91 #define OVERLAP(mod1, mod2) (INRANGE(mod1, mod2->mod_start) || \
  92                         INRANGE(mod1, mod2->mod_end))
  93         for(m = 0; m < n; m++) {
  94                 multiboot_module_t *thismod = &mod[m];
  95                 if(m == cmp_mod) continue;
  96                 if(OVERLAP(thismod, cmp))
  97                         return 1;
  98         }
  99         return 0;
 100 }
 101
 102 void get_parameters(u32_t ebx, kinfo_t *cbi)
 103 {
 104         multiboot_memory_map_t *mmap;
 105         multiboot_info_t *mbi = &cbi->mbi;
 106         int var_i,value_i, m, k;
 107         char *p;
 108         extern char _kern_phys_base, _kern_vir_base, _kern_size,
 109                 _kern_unpaged_start, _kern_unpaged_end;
 110         phys_bytes kernbase = (phys_bytes) &_kern_phys_base,
 111                 kernsize = (phys_bytes) &_kern_size;
 112 #define BUF 1024
 113         static char cmdline[BUF];
 114
 115         /* get our own copy of the multiboot info struct and module list */
 116         memcpy((void *) mbi, (void *) ebx, sizeof(*mbi));
 117
 118         /* Set various bits of info for the higher-level kernel. */
 119         cbi->mem_high_phys = 0;
 120         cbi->user_sp = (vir_bytes) &_kern_vir_base;
 121         cbi->vir_kern_start = (vir_bytes) &_kern_vir_base;
 122         cbi->bootstrap_start = (vir_bytes) &_kern_unpaged_start;
 123         cbi->bootstrap_len = (vir_bytes) &_kern_unpaged_end -
 124                 cbi->bootstrap_start;
 125         cbi->kmess = &kmess;
 126
 127         /* set some configurable defaults */
 128         cbi->do_serial_debug = 0;
 129         cbi->serial_debug_baud = 115200;
 130
 131         /* parse boot command line */
 132         if (mbi->flags&MULTIBOOT_INFO_CMDLINE) {
 133                 static char var[BUF];
 134                 static char value[BUF];
 135
 136                 /* Override values with cmdline argument */
 137                 memcpy(cmdline, (void *) mbi->cmdline, BUF);
 138                 p = cmdline;
 139                 while (*p) {
 140                         var_i = 0;
 141                         value_i = 0;
 142                         while (*p == ' ') p++;
 143                         if (!*p) break;
 144                         while (*p && *p != '=' && *p != ' ' && var_i < BUF - 1)
 145                                 var[var_i++] = *p++ ;
 146                         var[var_i] = 0;
 147                         if (*p++ != '=') continue; /* skip if not name=value */
 148                         while (*p && *p != ' ' && value_i < BUF - 1)
 149                                 value[value_i++] = *p++ ;
 150                         value[value_i] = 0;
 151
 152                         mb_set_param(cbi->param_buf, var, value, cbi);
 153                 }
 154         }
 155
 156         /* round user stack down to leave a gap to catch kernel
 157          * stack overflow; and to distinguish kernel and user addresses
 158          * at a glance (0xf.. vs 0xe..)
 159          */
 160         cbi->user_sp &= 0xF0000000;
 161         cbi->user_end = cbi->user_sp;
 162
 163         /* kernel bytes without bootstrap code/data that is currently
 164          * still needed but will be freed after bootstrapping.
 165          */
 166         kinfo.kernel_allocated_bytes = (phys_bytes) &_kern_size;
 167
 168         assert(!(cbi->bootstrap_start % I386_PAGE_SIZE));
 169         cbi->bootstrap_len = rounddown(cbi->bootstrap_len, I386_PAGE_SIZE);
 170         assert(mbi->flags & MULTIBOOT_INFO_MODS);
 171         assert(mbi->mods_count < MULTIBOOT_MAX_MODS);
 172         assert(mbi->mods_count > 0);
 173         memcpy(&cbi->module_list, (void *) mbi->mods_addr,
 174                 mbi->mods_count * sizeof(multiboot_module_t));
 175
 176         memset(cbi->memmap, 0, sizeof(cbi->memmap));
 177         /* mem_map has a variable layout */
 178         if(mbi->flags & MULTIBOOT_INFO_MEM_MAP) {
 179                 cbi->mmap_size = 0;
 180                 for (mmap = (multiboot_memory_map_t *) mbi->mmap_addr;
 181              (unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length;
 182                mmap = (multiboot_memory_map_t *)
 183                         ((unsigned long) mmap + mmap->size + sizeof(mmap->size))) {
 184                         if(mmap->type != MULTIBOOT_MEMORY_AVAILABLE) continue;
 185                         add_memmap(cbi, mmap->addr, mmap->len);
 186                 }
 187         } else {
 188                 assert(mbi->flags & MULTIBOOT_INFO_MEMORY);
 189                 add_memmap(cbi, 0, mbi->mem_lower_unused*1024);
 190                 add_memmap(cbi, 0x100000, mbi->mem_upper_unused*1024);
 191         }
 192
 193         /* Sanity check: the kernel nor any of the modules may overlap
 194          * with each other. Pretend the kernel is an extra module for a
 195          * second.
 196          */
 197         k = mbi->mods_count;
 198         assert(k < MULTIBOOT_MAX_MODS);
 199         cbi->module_list[k].mod_start = kernbase;
 200         cbi->module_list[k].mod_end = kernbase + kernsize;
 201         cbi->mods_with_kernel = mbi->mods_count+1;
 202         cbi->kern_mod = k;
 203
 204         for(m = 0; m < cbi->mods_with_kernel; m++) {
 205 #if 0
 206                 printf("checking overlap of module %08lx-%08lx\n",
 207                   cbi->module_list[m].mod_start, cbi->module_list[m].mod_end);
 208 #endif
 209                 if(overlaps(cbi->module_list, cbi->mods_with_kernel, m))
 210                         panic("overlapping boot modules/kernel");
 211                 /* We cut out the bits of memory that we know are
 212                  * occupied by the kernel and boot modules.
 213                  */
 214                 cut_memmap(cbi,
 215                         cbi->module_list[m].mod_start,
 216                         cbi->module_list[m].mod_end);
 217         }
 218 }
 219
 220 kinfo_t *pre_init(u32_t magic, u32_t ebx)
 221 {
 222         /* Get our own copy boot params pointed to by ebx.
 223          * Here we find out whether we should do serial output.
 224          */
 225         get_parameters(ebx, &kinfo);
 226
 227         assert(magic == MULTIBOOT_BOOTLOADER_MAGIC);
 228
 229         /* Make and load a pagetable that will map the kernel
 230          * to where it should be; but first a 1:1 mapping so
 231          * this code stays where it should be.
 232          */
 233         pg_clear();
 234         pg_identity(&kinfo);
 235         kinfo.freepde_start = pg_mapkernel();
 236         pg_load();
 237         vm_enable_paging();
 238
 239         /* Done, return boot info so it can be passed to kmain(). */
 240         return &kinfo;
 241 }
 242
 243 int send_sig(endpoint_t proc_nr, int sig_nr) { return 0; }
 244 void minix_shutdown(timer_t *t) { arch_shutdown(RBT_PANIC); }
 245 void busy_delay_ms(int x) { }