cosmopolitan/ape/lib/mapimage.c
Justine Tunney f0600a898c Fix metal bugs so deathstar.com runs in qemu (#20)
- Remove XD bit in page tables
- Fix cylinder+head+sector arithmetic
- Implement fstat() for serial file descriptors on metal

Here's how to boot an Actually Portable Executable in QEMU:

    make -j12 o//tool/viz/deathstar.com
    qemu-system-x86_64 -serial stdio -fda o//tool/viz/deathstar.com

Here's a screenshot of DEATHSTAR.COM booted in QEMU:
https://justine.lol/cosmopolitan/cosmo-metal-qemu.png

Thus metal support is in much better shape now, but still incomplete.
Only a few system calls have been polyfilled. To figure out which ones
your program needs, simply boot it in the blinkenlights emulator with a
breakpoint, and press CTRL-C to continue to the system call breakpoint.
If it doesn't break then you should be good. (Note: to emulate normally
you can press 'c' and use CTRL-T and ALT-T to tune the speed.)

    m=tiny
    make -j12 SILENT=0 MODE=$m          \
      o/$m/tool/build/blinkenlights.com \
      o/$m/tool/viz/deathstar.com
    o/$m/tool/build/blinkenlights.com   \
      -r -t -b systemfive.linux         \
      o/$m/tool/viz/deathstar.com

Thank @Theldus for the bug report that made this change possible.
Fixes #20 which explains this change further.
2021-01-16 17:52:15 -08:00

36 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,
(uintptr_t)_etext - IMAGE_BASE_VIRTUAL,
(uintptr_t)_end - IMAGE_BASE_VIRTUAL);
}