cosmopolitan/ape/lib/mapimage.c

37 lines
2.4 KiB
C

/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
╞══════════════════════════════════════════════════════════════════════════════╡
│ Copyright 2020 Justine Alexandra Roberts Tunney │
│ │
│ Permission to use, copy, modify, and/or distribute this software for │
│ any purpose with or without fee is hereby granted, provided that the │
│ above copyright notice and this permission notice appear in all copies. │
│ │
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
│ PERFORMANCE OF THIS SOFTWARE. │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "ape/lib/pc.h"
#include "ape/relocations.h"
#include "libc/runtime/runtime.h"
textreal static void __map_segment(uint64_t k, uint64_t a, uint64_t b) {
uint64_t *e;
for (; a < b; a += 0x1000) {
e = __getpagetableentry(IMAGE_BASE_VIRTUAL + a, 3, &g_pml4t, &g_ptsp_xlm);
*e = (IMAGE_BASE_REAL + a) | k;
}
}
textreal void __map_image(void) {
__map_segment(PAGE_V | PAGE_U, 0, (uintptr_t)_etext - IMAGE_BASE_VIRTUAL);
__map_segment(PAGE_V | PAGE_U | PAGE_RW | PAGE_XD,
(uintptr_t)_etext - IMAGE_BASE_VIRTUAL,
(uintptr_t)_end - IMAGE_BASE_VIRTUAL);
}