minix3/kernel/arch/earm/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 "string.h"
#include "arch_proto.h"
#include "direct_utils.h"
#include "bsp_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; }
static void setup_mbi(multiboot_info_t *mbi, char *bootargs);
/* String length used for mb_itoa */
#define ITOA_BUFFER_SIZE 20
/* Kernel may use memory */
int kernel_may_alloc = 1;
/* kernel bss */
extern u32_t _edata;
extern u32_t _end;
/* kernel unpaged bss */
extern char _kern_unpaged_edata;
extern char _kern_unpaged_end;
/**
*
* The following function combines a few things together
* that can well be done using standard libc like strlen/strstr
* and such but these are not available in pre_init stage.
*
* The function expects content to be in the form of space separated
* key value pairs.
* param content the contents to search in
* param key the key to find (this *should* include the key/value delimiter)
* param value a pointer to an initialized char * of at least value_max_len length
* param value_max_len the maximum length of the value to store in value including
* the end char
*
**/
int find_value(char * content,char * key,char *value,int value_max_len){
char *iter,*keyp;
int key_len,content_len,match_len,value_len;
/* return if the input is invalid */
if (key == NULL || content == NULL || value == NULL) {
return 1;
}
/* find the key and content length */
key_len = content_len =0;
for(iter = key ; *iter != '\0'; iter++, key_len++);
for(iter = content ; *iter != '\0'; iter++, content_len++);
/* return if key or content length invalid */
if (key_len == 0 || content_len == 0) {
return 1;
}
/* now find the key in the contents */
match_len =0;
for (iter = content ,keyp=key; match_len < key_len && *iter != '\0' ; iter++) {
if (*iter == *keyp) {
match_len++;
keyp++;
continue;
}
/* The current key does not match the value , reset */
match_len =0;
keyp=key;
}
if (match_len == key_len) {
printf("key found at %d %s\n", match_len, &content[match_len]);
value_len = 0;
/* copy the content to the value char iter already points to the first
char value */
while(*iter != '\0' && *iter != ' ' && value_len + 1< value_max_len) {
*value++ = *iter++;
value_len++;
}
*value='\0';
return 0;
}
return 1; /* not found */
}
static int mb_set_param(char *bigbuf,char *name,char *value, kinfo_t *cbi)
{
/* bigbuf contains a list of key=value pairs separated by \0 char.
* The list itself is ended by a second \0 terminator*/
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;
/* let q point to the end of the entry */
while (*q) q++;
/* now copy the remained of the buffer */
for (q++; q < bufend; q++, p++)
*p = *q;
break;
}
/* find the end of the buffer */
while (*p++);
p++;
}
/* find the first empty spot */
for (p = bigbuf; p < bufend && (*p || *(p + 1)); p++);
/* unless we are the first entry step over the delimiter */
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; /* end with a second delimiter */
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) <= thismod->mod_end)
#define OVERLAP(mod1, mod2) (INRANGE(mod1, mod2->mod_start) || \
INRANGE(mod1, mod2->mod_end))
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;
}
/* XXX: hard-coded stuff for modules */
#define MB_MODS_NR NR_BOOT_MODULES
#define MB_MODS_BASE 0x82000000
#define MB_MODS_ALIGN 0x00800000 /* 8 MB */
#define MB_MMAP_START 0x80000000
#define MB_MMAP_SIZE 0x10000000 /* 256 MB */
multiboot_module_t mb_modlist[MB_MODS_NR];
multiboot_memory_map_t mb_memmap;
void setup_mbi(multiboot_info_t *mbi, char *bootargs)
{
memset(mbi, 0, sizeof(*mbi));
mbi->flags = MULTIBOOT_INFO_MODS | MULTIBOOT_INFO_MEM_MAP |
MULTIBOOT_INFO_CMDLINE;
mbi->mi_mods_count = MB_MODS_NR;
mbi->mods_addr = (u32_t)&mb_modlist;
int i;
for (i = 0; i < MB_MODS_NR; ++i) {
mb_modlist[i].mod_start = MB_MODS_BASE + i * MB_MODS_ALIGN;
mb_modlist[i].mod_end = mb_modlist[i].mod_start + MB_MODS_ALIGN
- ARM_PAGE_SIZE;
mb_modlist[i].cmdline = 0;
}
/* morph the bootargs into multiboot */
mbi->cmdline = (u32_t) bootargs;
mbi->mmap_addr =(u32_t)&mb_memmap;
mbi->mmap_length = sizeof(mb_memmap);
mb_memmap.size = sizeof(multiboot_memory_map_t);
mb_memmap.mm_base_addr = MB_MMAP_START;
mb_memmap.mm_length = MB_MMAP_SIZE;
mb_memmap.type = MULTIBOOT_MEMORY_AVAILABLE;
}
void get_parameters(kinfo_t *cbi, char *bootargs)
{
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 */
setup_mbi(mbi, bootargs);
/* 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 = 1;
cbi->serial_debug_baud = 115200;
/* parse boot command line */
if (mbi->flags&MULTIBOOT_INFO_CMDLINE) {
static char var[BUF];
static char value[BUF];
/* Override values with cmdline argument */
memcpy(cmdline, (void *) mbi->cmdline, BUF);
p = cmdline;
while (*p) {
var_i = 0;
value_i = 0;
while (*p == ' ') p++; /* skip spaces */
if (!*p) break; /* is this the end? */
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(machine.board_id), cbi);
mb_set_param(cbi->param_buf, BOARDVARNAME,(char *)get_board_name(machine.board_id) , 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 % ARM_PAGE_SIZE));
cbi->bootstrap_len = rounddown(cbi->bootstrap_len, ARM_PAGE_SIZE);
assert(mbi->flags & MULTIBOOT_INFO_MODS);
assert(mbi->mi_mods_count < MULTIBOOT_MAX_MODS);
assert(mbi->mi_mods_count > 0);
memcpy(&cbi->module_list, (void *) mbi->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->flags & MULTIBOOT_INFO_MEM_MAP) {
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->size + sizeof(mmap->size))) {
if(mmap->type != MULTIBOOT_MEMORY_AVAILABLE) continue;
add_memmap(cbi, mmap->mm_base_addr, mmap->mm_length);
}
} else {
assert(mbi->flags & MULTIBOOT_INFO_MEMORY);
add_memmap(cbi, 0, mbi->mem_lower_unused*1024);
add_memmap(cbi, 0x100000, mbi->mem_upper_unused*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);
}
}
/*
* During low level init many things are not supposed to work
* serial being one of them. We therefore can't rely on the
* serial to debug. POORMANS_FAILURE_NOTIFICATION can be used
* before we setup our own vector table and will result in calling
* the bootloader's debugging methods that will hopefully show some
* information like the currnet PC at on the serial.
*/
#define POORMANS_FAILURE_NOTIFICATION asm volatile("svc #00\n")
/* use the passed cmdline argument to determine the machine id */
void set_machine_id(char *cmdline)
{
char boardname[20];
memset(boardname,'\0',20);
if (find_value(cmdline,"board_name=",boardname,20)){
/* we expect the bootloader to pass a board_name as argument
* this however did not happen and given we still are in early
* boot we can't use the serial. We therefore generate an interrupt
* and hope the bootloader will do something nice with it */
POORMANS_FAILURE_NOTIFICATION;
}
machine.board_id = get_board_id_by_short_name(boardname);
if (machine.board_id ==0){
/* same thing as above there is no safe escape */
POORMANS_FAILURE_NOTIFICATION;
}
}
kinfo_t *pre_init(int argc, char **argv)
{
char *bootargs;
/* This is the main "c" entry point into the kernel. It gets called
from head.S */
/* Clear BSS */
memset(&_edata, 0, (u32_t)&_end - (u32_t)&_edata);
memset(&_kern_unpaged_edata, 0, (u32_t)&_kern_unpaged_end - (u32_t)&_kern_unpaged_edata);
/* we get called in a c like fashion where the first arg
* is the program name (load address) and the rest are
* arguments. by convention the second argument is the
* command line */
if (argc != 2) {
POORMANS_FAILURE_NOTIFICATION;
}
bootargs = argv[1];
set_machine_id(bootargs);
bsp_ser_init();
/* Get our own copy boot params pointed to by ebx.
* Here we find out whether we should do serial output.
*/
get_parameters(&kinfo, bootargs);
/* 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.
*/
dcache_clean(); /* clean the caches */
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;
}
/* pre_init gets executed at the memory location where the kernel was loaded by the boot loader.
* at that stage we only have a minimum set of functionality present (all symbols gets renamed to
* ensure this). The following methods are used in that context. Once we jump to kmain they are no
* longer used and the "real" implementations are visible
*/
void send_diag_sig(void) { }
void minix_shutdown(minix_timer_t *t) { arch_shutdown(0); }
void busy_delay_ms(int x) { }
int raise(int n) { panic("raise(%d)\n", n); }
int kern_phys_map_ptr( phys_bytes base_address, vir_bytes io_size, int vm_flags,
struct kern_phys_map * priv, vir_bytes ptr) {};
struct machine machine; /* pre init stage machine */