minix/kernel/arch/earm/protect.c

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2012-10-08 03:38:03 +02:00
/* This file contains code for initialization of protected mode, to initialize
* code and data segment descriptors, and to initialize global descriptors
* for local descriptors in the process table.
*/
#include <string.h>
#include <assert.h>
#include <machine/multiboot.h>
#include "kernel/kernel.h"
#include "kernel/proc.h"
#include "archconst.h"
#include "arch_proto.h"
#include <libexec.h>
struct tss_s tss[CONFIG_MAX_CPUS];
extern int exc_vector_table;
int prot_init_done = 0;
phys_bytes vir2phys(void *vir)
{
extern char _kern_vir_base, _kern_phys_base; /* in kernel.lds */
u32_t offset = (vir_bytes) &_kern_vir_base -
(vir_bytes) &_kern_phys_base;
return (phys_bytes)vir - offset;
}
int tss_init(unsigned cpu, void * kernel_stack)
{
struct tss_s * t = &tss[cpu];
/*
* make space for process pointer and cpu id and point to the first
* usable word
*/
t->sp0 = ((unsigned) kernel_stack) - ARM_STACK_TOP_RESERVED;
/*
* set the cpu id at the top of the stack so we know on which cpu is
* this stak in use when we trap to kernel
*/
*((reg_t *)(t->sp0 + 1 * sizeof(reg_t))) = cpu;
return 0;
}
multiboot_module_t *bootmod(int pnr)
{
int i;
assert(pnr >= 0);
/* Search for desired process in boot process
* list. The first NR_TASKS ones do not correspond
* to a module, however, so we don't search those.
*/
for(i = NR_TASKS; i < NR_BOOT_PROCS; i++) {
int p;
p = i - NR_TASKS;
if(image[i].proc_nr == pnr) {
assert(p < MULTIBOOT_MAX_MODS);
assert(p < kinfo.mbi.mods_count);
return &kinfo.module_list[p];
}
}
panic("boot module %d not found", pnr);
}
int booting_cpu = 0;
void prot_init()
{
write_vbar((reg_t)&exc_vector_table);
/* Set up a new post-relocate bootstrap pagetable so that
* we can map in VM, and we no longer rely on pre-relocated
* data.
*/
pg_clear();
pg_identity(&kinfo); /* Still need 1:1 for device memory . */
pg_mapkernel();
pg_load();
prot_init_done = 1;
}
static int alloc_for_vm = 0;
void arch_post_init(void)
{
/* Let memory mapping code know what's going on at bootstrap time */
struct proc *vm;
vm = proc_addr(VM_PROC_NR);
get_cpulocal_var(ptproc) = vm;
pg_info(&vm->p_seg.p_ttbr, &vm->p_seg.p_ttbr_v);
}
int libexec_pg_alloc(struct exec_info *execi, off_t vaddr, size_t len)
{
pg_map(PG_ALLOCATEME, vaddr, vaddr+len, &kinfo);
pg_load();
memset((char *) vaddr, 0, len);
alloc_for_vm += len;
return OK;
}
void arch_boot_proc(struct boot_image *ip, struct proc *rp)
{
multiboot_module_t *mod;
if(rp->p_nr < 0) return;
mod = bootmod(rp->p_nr);
/* Important special case: we put VM in the bootstrap pagetable
* so it can run.
*/
if(rp->p_nr == VM_PROC_NR) {
struct exec_info execi;
memset(&execi, 0, sizeof(execi));
/* exec parameters */
execi.stack_high = kinfo.user_sp;
execi.stack_size = 32 * 1024; /* not too crazy as it must be preallocated */
execi.proc_e = ip->endpoint;
execi.hdr = (char *) mod->mod_start; /* phys mem direct */
execi.hdr_len = mod->mod_end - mod->mod_start;
strcpy(execi.progname, ip->proc_name);
execi.frame_len = 0;
/* callbacks for use in the kernel */
execi.copymem = libexec_copy_memcpy;
execi.clearmem = libexec_clear_memset;
execi.allocmem_prealloc = libexec_pg_alloc;
execi.allocmem_ondemand = libexec_pg_alloc;
execi.clearproc = NULL;
/* parse VM ELF binary and alloc/map it into bootstrap pagetable */
libexec_load_elf(&execi);
/* Initialize the server stack pointer. Take it down three words
* to give startup code something to use as "argc", "argv" and "envp".
*/
arch_proc_init(rp, execi.pc, kinfo.user_sp - 3*4, ip->proc_name);
/* Free VM blob that was just copied into existence. */
cut_memmap(&kinfo, mod->mod_start, mod->mod_end);
/* Remember them */
kinfo.vm_allocated_bytes = alloc_for_vm;
}
}