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