kernel/arch/earm/pre_init.c

   1 #define UNPAGED 1       /* for proper kmain() prototype */
   2
   3 #include "kernel/kernel.h"
   4 #include <assert.h>
   5 #include <stdlib.h>
   6 #include <minix/minlib.h>
   7 #include <minix/const.h>
   8 #include <minix/type.h>
   9 #include <minix/board.h>
  10 #include <minix/com.h>
  11 #include <sys/types.h>
  12 #include <sys/param.h>
  13 #include <sys/reboot.h>
  14 #include "string.h"
  15 #include "arch_proto.h"
  16 #include "direct_utils.h"
  17 #include "bsp_serial.h"
  18 #include "glo.h"
  19 #include <machine/multiboot.h>
  20
  21 #if USE_SYSDEBUG
  22 #define MULTIBOOT_VERBOSE 1
  23 #endif
  24
  25 /* to-be-built kinfo struct, diagnostics buffer */
  26 kinfo_t kinfo;
  27 struct kmessages kmessages;
  28
  29 /* pg_utils.c uses this; in this phase, there is a 1:1 mapping. */
  30 phys_bytes vir2phys(void *addr) { return (phys_bytes) addr; }
  31
  32 static void setup_mbi(multiboot_info_t *mbi, char *bootargs);
  33
  34 /* String length used for mb_itoa */
  35 #define ITOA_BUFFER_SIZE 20
  36
  37 /* Kernel may use memory */
  38 int kernel_may_alloc = 1;
  39
  40 extern u32_t _edata;
  41 extern u32_t _end;
  42
  43 /**
  44  *
  45  * The following function combines a few things together
  46  * that can well be done using standard libc like strlen/strstr
  47  * and such but these are not available in pre_init stage.
  48  *
  49  * The function expects content to be in the form of space separated
  50  * key value pairs.
  51  * param content the contents to search in
  52  * param key the key to find (this *should* include the key/value delimiter)
  53  * param value a pointer to an initialized char * of at least value_max_len length
  54  * param value_max_len the maximum length of the value to store in value including
  55  *       the end char
  56  *
  57 **/
  58 int find_value(char * content,char * key,char *value,int value_max_len){
  59
  60         char *iter,*keyp;
  61         int key_len,content_len,match_len,value_len;
  62
  63         /* return if the input is invalid */
  64         if  (key == NULL || content == NULL || value == NULL) {
  65                 return 1;
  66         }
  67
  68         /* find the key and content length */
  69         key_len = content_len =0;
  70         for(iter = key ; *iter != '\0'; iter++, key_len++);
  71         for(iter = content ; *iter != '\0'; iter++, content_len++);
  72
  73         /* return if key or content length invalid */
  74         if (key_len == 0 || content_len == 0) {
  75                 return 1;
  76         }
  77
  78         /* now find the key in the contents */
  79         match_len =0;
  80         for (iter = content ,keyp=key; match_len < key_len && *iter != '\0' ; iter++) {
  81                 if (*iter == *keyp) {
  82                         match_len++;
  83                         keyp++;
  84                         continue;
  85                 }
  86                 /* The current key does not match the value , reset */
  87                 match_len =0;
  88                 keyp=key;
  89         }
  90
  91         if (match_len == key_len) {
  92                 printf("key found at %d %s\n", match_len, &content[match_len]);
  93                 value_len = 0;
  94                 /* copy the content to the value char iter already points to the first
  95                    char value */
  96                 while(*iter != '\0' && *iter != ' ' && value_len  + 1< value_max_len) {
  97                         *value++ = *iter++;
  98                         value_len++;
  99                 }
 100                 *value='\0';
 101                 return 0;
 102         }
 103         return 1; /* not found */
 104 }
 105
 106 static int mb_set_param(char *bigbuf,char *name,char *value, kinfo_t *cbi)
 107 {
 108         /* bigbuf contains a list of key=value pairs separated by \0 char.
 109          * The list itself is ended by a second \0 terminator*/
 110         char *p = bigbuf;
 111         char *bufend = bigbuf + MULTIBOOT_PARAM_BUF_SIZE;
 112         char *q;
 113         int namelen = strlen(name);
 114         int valuelen = strlen(value);
 115
 116         /* Some variables we recognize */
 117         if(!strcmp(name, SERVARNAME)) { cbi->do_serial_debug = 1; }
 118         if(!strcmp(name, SERBAUDVARNAME)) { cbi->serial_debug_baud = atoi(value); }
 119
 120         /* Delete the item if already exists */
 121         while (*p) {
 122                 if (strncmp(p, name, namelen) == 0 && p[namelen] == '=') {
 123                         q = p;
 124                         /* let q point to the end of the entry */
 125                         while (*q) q++;
 126                         /* now copy the remained of the buffer */
 127                         for (q++; q < bufend; q++, p++)
 128                                 *p = *q;
 129                         break;
 130                 }
 131
 132                 /* find the end of the buffer */
 133                 while (*p++);
 134                 p++;
 135         }
 136
 137
 138         /* find the first empty spot */
 139         for (p = bigbuf; p < bufend && (*p || *(p + 1)); p++);
 140
 141         /* unless we are the first entry step over the delimiter */
 142         if (p > bigbuf) p++;
 143
 144         /* Make sure there's enough space for the new parameter */
 145         if (p + namelen + valuelen + 3 > bufend) {
 146                 return -1;
 147         }
 148
 149         strcpy(p, name);
 150         p[namelen] = '=';
 151         strcpy(p + namelen + 1, value);
 152         p[namelen + valuelen + 1] = 0;
 153         p[namelen + valuelen + 2] = 0; /* end with a second delimiter */
 154         return 0;
 155 }
 156
 157 int overlaps(multiboot_module_t *mod, int n, int cmp_mod)
 158 {
 159         multiboot_module_t *cmp = &mod[cmp_mod];
 160         int m;
 161
 162 #define INRANGE(mod, v) ((v) >= mod->mod_start && (v) <= thismod->mod_end)
 163 #define OVERLAP(mod1, mod2) (INRANGE(mod1, mod2->mod_start) || \
 164             INRANGE(mod1, mod2->mod_end))
 165         for(m = 0; m < n; m++) {
 166                 multiboot_module_t *thismod = &mod[m];
 167                 if(m == cmp_mod) continue;
 168                 if(OVERLAP(thismod, cmp)) {
 169                         return 1;
 170                 }
 171         }
 172         return 0;
 173 }
 174
 175 /* XXX: hard-coded stuff for modules */
 176 #define MB_MODS_NR NR_BOOT_MODULES
 177 #define MB_MODS_BASE  0x82000000
 178 #define MB_MODS_ALIGN 0x00800000 /* 8 MB */
 179 #define MB_MMAP_START 0x80000000
 180 #define MB_MMAP_SIZE  0x10000000 /* 256 MB */
 181
 182 multiboot_module_t mb_modlist[MB_MODS_NR];
 183 multiboot_memory_map_t mb_memmap;
 184
 185 void setup_mbi(multiboot_info_t *mbi, char *bootargs)
 186 {
 187         memset(mbi, 0, sizeof(*mbi));
 188         mbi->flags = MULTIBOOT_INFO_MODS | MULTIBOOT_INFO_MEM_MAP |
 189                         MULTIBOOT_INFO_CMDLINE;
 190         mbi->mi_mods_count = MB_MODS_NR;
 191         mbi->mods_addr = (u32_t)&mb_modlist;
 192
 193         int i;
 194         for (i = 0; i < MB_MODS_NR; ++i) {
 195                 mb_modlist[i].mod_start = MB_MODS_BASE + i * MB_MODS_ALIGN;
 196                 mb_modlist[i].mod_end = mb_modlist[i].mod_start + MB_MODS_ALIGN
 197                     - ARM_PAGE_SIZE;
 198                 mb_modlist[i].cmdline = 0;
 199         }
 200
 201         /* morph the bootargs into multiboot */
 202         mbi->cmdline = (u32_t) bootargs;
 203
 204         mbi->mmap_addr =(u32_t)&mb_memmap;
 205         mbi->mmap_length = sizeof(mb_memmap);
 206
 207         mb_memmap.size = sizeof(multiboot_memory_map_t);
 208         mb_memmap.mm_base_addr = MB_MMAP_START;
 209         mb_memmap.mm_length  = MB_MMAP_SIZE;
 210         mb_memmap.type = MULTIBOOT_MEMORY_AVAILABLE;
 211 }
 212
 213 void get_parameters(kinfo_t *cbi, char *bootargs)
 214 {
 215         multiboot_memory_map_t *mmap;
 216         multiboot_info_t *mbi = &cbi->mbi;
 217         int var_i,value_i, m, k;
 218         char *p;
 219         extern char _kern_phys_base, _kern_vir_base, _kern_size,
 220             _kern_unpaged_start, _kern_unpaged_end;
 221         phys_bytes kernbase = (phys_bytes) &_kern_phys_base,
 222             kernsize = (phys_bytes) &_kern_size;
 223 #define BUF 1024
 224         static char cmdline[BUF];
 225
 226         /* get our own copy of the multiboot info struct and module list */
 227         setup_mbi(mbi, bootargs);
 228
 229         /* Set various bits of info for the higher-level kernel. */
 230         cbi->mem_high_phys = 0;
 231         cbi->user_sp = (vir_bytes) &_kern_vir_base;
 232         cbi->vir_kern_start = (vir_bytes) &_kern_vir_base;
 233         cbi->bootstrap_start = (vir_bytes) &_kern_unpaged_start;
 234         cbi->bootstrap_len = (vir_bytes) &_kern_unpaged_end -
 235                 cbi->bootstrap_start;
 236         cbi->kmess = &kmess;
 237
 238         /* set some configurable defaults */
 239         cbi->do_serial_debug = 1;
 240         cbi->serial_debug_baud = 115200;
 241
 242         /* parse boot command line */
 243         if (mbi->flags&MULTIBOOT_INFO_CMDLINE) {
 244                 static char var[BUF];
 245                 static char value[BUF];
 246
 247                 /* Override values with cmdline argument */
 248                 memcpy(cmdline, (void *) mbi->cmdline, BUF);
 249                 p = cmdline;
 250                 while (*p) {
 251                         var_i = 0;
 252                         value_i = 0;
 253                         while (*p == ' ') p++; /* skip spaces */
 254                         if (!*p) break; /* is this the end? */
 255                         while (*p && *p != '=' && *p != ' ' && var_i < BUF - 1)
 256                                 var[var_i++] = *p++ ;
 257                         var[var_i] = 0;
 258                         if (*p++ != '=') continue; /* skip if not name=value */
 259                         while (*p && *p != ' ' && value_i < BUF - 1) {
 260                                 value[value_i++] = *p++ ;
 261                         }
 262                         value[value_i] = 0;
 263
 264                         mb_set_param(cbi->param_buf, var, value, cbi);
 265                 }
 266         }
 267
 268         /* let higher levels know what we are booting on */
 269         mb_set_param(cbi->param_buf, ARCHVARNAME, (char *)get_board_arch_name(machine.board_id), cbi);
 270         mb_set_param(cbi->param_buf, BOARDVARNAME,(char *)get_board_name(machine.board_id) , cbi);
 271
 272
 273         /* round user stack down to leave a gap to catch kernel
 274          * stack overflow; and to distinguish kernel and user addresses
 275          * at a glance (0xf.. vs 0xe..)
 276          */
 277         cbi->user_sp &= 0xF0000000;
 278         cbi->user_end = cbi->user_sp;
 279
 280         /* kernel bytes without bootstrap code/data that is currently
 281          * still needed but will be freed after bootstrapping.
 282          */
 283         kinfo.kernel_allocated_bytes = (phys_bytes) &_kern_size;
 284         kinfo.kernel_allocated_bytes -= cbi->bootstrap_len;
 285
 286         assert(!(cbi->bootstrap_start % ARM_PAGE_SIZE));
 287         cbi->bootstrap_len = rounddown(cbi->bootstrap_len, ARM_PAGE_SIZE);
 288         assert(mbi->flags & MULTIBOOT_INFO_MODS);
 289         assert(mbi->mi_mods_count < MULTIBOOT_MAX_MODS);
 290         assert(mbi->mi_mods_count > 0);
 291         memcpy(&cbi->module_list, (void *) mbi->mods_addr,
 292                 mbi->mi_mods_count * sizeof(multiboot_module_t));
 293
 294         memset(cbi->memmap, 0, sizeof(cbi->memmap));
 295         /* mem_map has a variable layout */
 296         if(mbi->flags & MULTIBOOT_INFO_MEM_MAP) {
 297                 cbi->mmap_size = 0;
 298                 for (mmap = (multiboot_memory_map_t *) mbi->mmap_addr;
 299              (unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length;
 300                mmap = (multiboot_memory_map_t *)
 301                         ((unsigned long) mmap + mmap->size + sizeof(mmap->size))) {
 302                         if(mmap->type != MULTIBOOT_MEMORY_AVAILABLE) continue;
 303                         add_memmap(cbi, mmap->mm_base_addr, mmap->mm_length);
 304                 }
 305         } else {
 306                 assert(mbi->flags & MULTIBOOT_INFO_MEMORY);
 307                 add_memmap(cbi, 0, mbi->mem_lower_unused*1024);
 308                 add_memmap(cbi, 0x100000, mbi->mem_upper_unused*1024);
 309         }
 310
 311         /* Sanity check: the kernel nor any of the modules may overlap
 312          * with each other. Pretend the kernel is an extra module for a
 313          * second.
 314          */
 315         k = mbi->mi_mods_count;
 316         assert(k < MULTIBOOT_MAX_MODS);
 317         cbi->module_list[k].mod_start = kernbase;
 318         cbi->module_list[k].mod_end = kernbase + kernsize;
 319         cbi->mods_with_kernel = mbi->mi_mods_count+1;
 320         cbi->kern_mod = k;
 321
 322         for(m = 0; m < cbi->mods_with_kernel; m++) {
 323 #if 0
 324                 printf("checking overlap of module %08lx-%08lx\n",
 325                   cbi->module_list[m].mod_start, cbi->module_list[m].mod_end);
 326 #endif
 327                 if(overlaps(cbi->module_list, cbi->mods_with_kernel, m))
 328                         panic("overlapping boot modules/kernel");
 329                 /* We cut out the bits of memory that we know are
 330                  * occupied by the kernel and boot modules.
 331                  */
 332                 cut_memmap(cbi,
 333                         cbi->module_list[m].mod_start,
 334                         cbi->module_list[m].mod_end);
 335         }
 336 }
 337
 338 /*
 339  * During low level init many things are not supposed to work
 340  * serial being one of them. We therefore can't rely on the
 341  * serial to debug. POORMANS_FAILURE_NOTIFICATION can be used
 342  * before we setup our own vector table and will result in calling
 343  * the bootloader's debugging methods that will hopefully show some
 344  * information like the currnet PC at on the serial.
 345  */
 346 #define POORMANS_FAILURE_NOTIFICATION  asm volatile("svc #00\n")
 347
 348 /* use the passed cmdline argument to determine the machine id */
 349 void set_machine_id(char *cmdline)
 350 {
 351
 352         char boardname[20];
 353         memset(boardname,'\0',20);
 354         if (find_value(cmdline,"board_name=",boardname,20)){
 355                 /* we expect the bootloader to pass a board_name as argument
 356                  * this however did not happen and given we still are in early
 357                  * boot we can't use the serial. We therefore generate an interrupt
 358                  * and hope the bootloader will do something nice with it */
 359                 POORMANS_FAILURE_NOTIFICATION;
 360         }
 361         machine.board_id = get_board_id_by_short_name(boardname);
 362
 363         if (machine.board_id ==0){
 364                 /* same thing as above there is no safe escape */
 365                 POORMANS_FAILURE_NOTIFICATION;
 366         }
 367 }
 368
 369 kinfo_t *pre_init(int argc, char **argv)
 370 {
 371         char *bootargs;
 372         /* This is the main "c" entry point into the kernel. It gets called
 373            from head.S */
 374
 375         /* Clear BSS */
 376         memset(&_edata, 0, (u32_t)&_end - (u32_t)&_edata);
 377
 378         /* we get called in a c like fashion where the first arg
 379          * is the program name (load address) and the rest are
 380          * arguments. by convention the second argument is the
 381          *  command line */
 382         if (argc != 2) {
 383                 POORMANS_FAILURE_NOTIFICATION;
 384         }
 385
 386         bootargs = argv[1];
 387         set_machine_id(bootargs);
 388         bsp_ser_init();
 389         /* Get our own copy boot params pointed to by ebx.
 390          * Here we find out whether we should do serial output.
 391          */
 392         get_parameters(&kinfo, bootargs);
 393
 394         /* Make and load a pagetable that will map the kernel
 395          * to where it should be; but first a 1:1 mapping so
 396          * this code stays where it should be.
 397          */
 398         dcache_clean(); /* clean the caches */
 399         pg_clear();
 400         pg_identity(&kinfo);
 401         kinfo.freepde_start = pg_mapkernel();
 402         pg_load();
 403         vm_enable_paging();
 404
 405         /* Done, return boot info so it can be passed to kmain(). */
 406         return &kinfo;
 407 }
 408
 409 /* pre_init gets executed at the memory location where the kernel was loaded by the boot loader.
 410  * at that stage we only have a minimum set of functionality present (all symbols gets renamed to
 411  * ensure this). The following methods are used in that context. Once we jump to kmain they are no
 412  * longer used and the "real" implementations are visible
 413  */
 414 void send_diag_sig(void) { }
 415 void minix_shutdown(minix_timer_t *t) { arch_shutdown(0); }
 416 void busy_delay_ms(int x) { }
 417 int raise(int n) { panic("raise(%d)\n", n); }
 418 int kern_phys_map_ptr( phys_bytes base_address, vir_bytes io_size, int vm_flags,
 419 struct kern_phys_map * priv, vir_bytes ptr) {};
 420 struct machine machine; /* pre init stage machine */