minix3/kernel/arch/i386/pre_init.c

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2020-02-21 00:59:27 +05:30
#define UNPAGED 1 /* for proper kmain() prototype */
#include "kernel/kernel.h"
#include <assert.h>
#include <stdlib.h>
#include <minix/minlib.h>
#include <minix/const.h>
#include <minix/type.h>
#include <minix/board.h>
#include <minix/com.h>
#include <sys/types.h>
#include <sys/param.h>
#include <sys/reboot.h>
#include <machine/partition.h>
#include "string.h"
#include "arch_proto.h"
#include "direct_utils.h"
#include "serial.h"
#include "glo.h"
#include <machine/multiboot.h>
#if USE_SYSDEBUG
#define MULTIBOOT_VERBOSE 1
#endif
/* to-be-built kinfo struct, diagnostics buffer */
kinfo_t kinfo;
struct kmessages kmessages;
/* pg_utils.c uses this; in this phase, there is a 1:1 mapping. */
phys_bytes vir2phys(void *addr) { return (phys_bytes) addr; }
/* mb_utils.c uses this; we can reach it directly */
char *video_mem = (char *) MULTIBOOT_VIDEO_BUFFER;
/* String length used for mb_itoa */
#define ITOA_BUFFER_SIZE 20
/* Kernel may use memory */
int kernel_may_alloc = 1;
static int mb_set_param(char *bigbuf, char *name, char *value, kinfo_t *cbi)
{
char *p = bigbuf;
char *bufend = bigbuf + MULTIBOOT_PARAM_BUF_SIZE;
char *q;
int namelen = strlen(name);
int valuelen = strlen(value);
/* Some variables we recognize */
if(!strcmp(name, SERVARNAME)) { cbi->do_serial_debug = 1; }
if(!strcmp(name, SERBAUDVARNAME)) { cbi->serial_debug_baud = atoi(value); }
/* Delete the item if already exists */
while (*p) {
if (strncmp(p, name, namelen) == 0 && p[namelen] == '=') {
q = p;
while (*q) q++;
for (q++; q < bufend; q++, p++)
*p = *q;
break;
}
while (*p++)
;
p++;
}
for (p = bigbuf; p < bufend && (*p || *(p + 1)); p++)
;
if (p > bigbuf) p++;
/* Make sure there's enough space for the new parameter */
if (p + namelen + valuelen + 3 > bufend)
return -1;
strcpy(p, name);
p[namelen] = '=';
strcpy(p + namelen + 1, value);
p[namelen + valuelen + 1] = 0;
p[namelen + valuelen + 2] = 0;
return 0;
}
int overlaps(multiboot_module_t *mod, int n, int cmp_mod)
{
multiboot_module_t *cmp = &mod[cmp_mod];
int m;
#define INRANGE(mod, v) ((v) >= mod->mod_start && (v) < mod->mod_end)
#define OVERLAP(mod1, mod2) (INRANGE(mod1, mod2->mod_start) || \
INRANGE(mod1, mod2->mod_end-1))
for(m = 0; m < n; m++) {
multiboot_module_t *thismod = &mod[m];
if(m == cmp_mod) continue;
if(OVERLAP(thismod, cmp))
return 1;
}
return 0;
}
void get_parameters(u32_t ebx, kinfo_t *cbi)
{
multiboot_memory_map_t *mmap;
multiboot_info_t *mbi = &cbi->mbi;
int var_i,value_i, m, k;
char *p;
extern char _kern_phys_base, _kern_vir_base, _kern_size,
_kern_unpaged_start, _kern_unpaged_end;
phys_bytes kernbase = (phys_bytes) &_kern_phys_base,
kernsize = (phys_bytes) &_kern_size;
#define BUF 1024
static char cmdline[BUF];
/* get our own copy of the multiboot info struct and module list */
memcpy((void *) mbi, (void *) ebx, sizeof(*mbi));
/* Set various bits of info for the higher-level kernel. */
cbi->mem_high_phys = 0;
cbi->user_sp = (vir_bytes) &_kern_vir_base;
cbi->vir_kern_start = (vir_bytes) &_kern_vir_base;
cbi->bootstrap_start = (vir_bytes) &_kern_unpaged_start;
cbi->bootstrap_len = (vir_bytes) &_kern_unpaged_end -
cbi->bootstrap_start;
cbi->kmess = &kmess;
/* set some configurable defaults */
cbi->do_serial_debug = 0;
cbi->serial_debug_baud = 115200;
/* parse boot command line */
if (mbi->mi_flags & MULTIBOOT_INFO_HAS_CMDLINE) {
static char var[BUF];
static char value[BUF];
/* Override values with cmdline argument */
memcpy(cmdline, (void *) mbi->mi_cmdline, BUF);
p = cmdline;
while (*p) {
var_i = 0;
value_i = 0;
while (*p == ' ') p++;
if (!*p) break;
while (*p && *p != '=' && *p != ' ' && var_i < BUF - 1)
var[var_i++] = *p++ ;
var[var_i] = 0;
if (*p++ != '=') continue; /* skip if not name=value */
while (*p && *p != ' ' && value_i < BUF - 1)
value[value_i++] = *p++ ;
value[value_i] = 0;
mb_set_param(cbi->param_buf, var, value, cbi);
}
}
/* let higher levels know what we are booting on */
mb_set_param(cbi->param_buf, ARCHVARNAME, (char *)get_board_arch_name(BOARD_ID_INTEL), cbi);
mb_set_param(cbi->param_buf, BOARDVARNAME,(char *)get_board_name(BOARD_ID_INTEL) , cbi);
/* round user stack down to leave a gap to catch kernel
* stack overflow; and to distinguish kernel and user addresses
* at a glance (0xf.. vs 0xe..)
*/
cbi->user_sp &= 0xF0000000;
cbi->user_end = cbi->user_sp;
/* kernel bytes without bootstrap code/data that is currently
* still needed but will be freed after bootstrapping.
*/
kinfo.kernel_allocated_bytes = (phys_bytes) &_kern_size;
kinfo.kernel_allocated_bytes -= cbi->bootstrap_len;
assert(!(cbi->bootstrap_start % I386_PAGE_SIZE));
cbi->bootstrap_len = rounddown(cbi->bootstrap_len, I386_PAGE_SIZE);
assert(mbi->mi_flags & MULTIBOOT_INFO_HAS_MODS);
assert(mbi->mi_mods_count < MULTIBOOT_MAX_MODS);
assert(mbi->mi_mods_count > 0);
memcpy(&cbi->module_list, (void *) mbi->mi_mods_addr,
mbi->mi_mods_count * sizeof(multiboot_module_t));
memset(cbi->memmap, 0, sizeof(cbi->memmap));
/* mem_map has a variable layout */
if(mbi->mi_flags & MULTIBOOT_INFO_HAS_MMAP) {
cbi->mmap_size = 0;
for (mmap = (multiboot_memory_map_t *) mbi->mmap_addr;
(unsigned long) mmap < mbi->mmap_addr + mbi->mmap_length;
mmap = (multiboot_memory_map_t *)
((unsigned long) mmap + mmap->mm_size + sizeof(mmap->mm_size))) {
if(mmap->mm_type != MULTIBOOT_MEMORY_AVAILABLE) continue;
add_memmap(cbi, mmap->mm_base_addr, mmap->mm_length);
}
} else {
assert(mbi->mi_flags & MULTIBOOT_INFO_HAS_MEMORY);
add_memmap(cbi, 0, mbi->mi_mem_lower*1024);
add_memmap(cbi, 0x100000, mbi->mi_mem_upper*1024);
}
/* Sanity check: the kernel nor any of the modules may overlap
* with each other. Pretend the kernel is an extra module for a
* second.
*/
k = mbi->mi_mods_count;
assert(k < MULTIBOOT_MAX_MODS);
cbi->module_list[k].mod_start = kernbase;
cbi->module_list[k].mod_end = kernbase + kernsize;
cbi->mods_with_kernel = mbi->mi_mods_count+1;
cbi->kern_mod = k;
for(m = 0; m < cbi->mods_with_kernel; m++) {
#if 0
printf("checking overlap of module %08lx-%08lx\n",
cbi->module_list[m].mod_start, cbi->module_list[m].mod_end);
#endif
if(overlaps(cbi->module_list, cbi->mods_with_kernel, m))
panic("overlapping boot modules/kernel");
/* We cut out the bits of memory that we know are
* occupied by the kernel and boot modules.
*/
cut_memmap(cbi,
cbi->module_list[m].mod_start,
cbi->module_list[m].mod_end);
}
}
kinfo_t *pre_init(u32_t magic, u32_t ebx)
{
assert(magic == MULTIBOOT_INFO_MAGIC);
/* Get our own copy boot params pointed to by ebx.
* Here we find out whether we should do serial output.
*/
get_parameters(ebx, &kinfo);
/* Make and load a pagetable that will map the kernel
* to where it should be; but first a 1:1 mapping so
* this code stays where it should be.
*/
pg_clear();
pg_identity(&kinfo);
kinfo.freepde_start = pg_mapkernel();
pg_load();
vm_enable_paging();
/* Done, return boot info so it can be passed to kmain(). */
return &kinfo;
}
void send_diag_sig(void) { }
void minix_shutdown(minix_timer_t *t) { arch_shutdown(0); }
void busy_delay_ms(int x) { }
int raise(int sig) { panic("raise(%d)\n", sig); }