minix/kernel/arch/earm/protect.c
Ben Gras 0cfff08e56 libexec: mmap support, prealloc variants
In libexec, split the memory allocation method into cleared and
non-cleared. Cleared gives zeroed memory, non-cleared gives 'junk'
memory (that will be overwritten anyway, and so needn't be cleared)
that is faster to get.

Also introduce the 'memmap' method that can be used, if available,
to map code and data from executables into a process using the
third-party mmap() mode.

Change-Id: I26694fd3c21deb8b97e01ed675dfc14719b0672b
2013-04-24 10:18:16 +00:00

161 lines
3.9 KiB
C

/* 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 = 64 * 1024; /* not too crazy as it must be preallocated */
execi.proc_e = ip->endpoint;
execi.hdr = (char *) mod->mod_start; /* phys mem direct */
execi.filesize = 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_cleared = libexec_pg_alloc;
execi.allocmem_prealloc_junk = 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. */
add_memmap(&kinfo, mod->mod_start, mod->mod_end-mod->mod_start);
mod->mod_end = mod->mod_start = 0;
/* Remember them */
kinfo.vm_allocated_bytes = alloc_for_vm;
}
}