/*-*- 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 │
│ │
│ This program is free software; you can redistribute it and/or modify │
│ it under the terms of the GNU General Public License as published by │
│ the Free Software Foundation; version 2 of the License. │
│ │
│ This program is distributed in the hope that it will be useful, but │
│ WITHOUT ANY WARRANTY; without even the implied warranty of │
│ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU │
│ General Public License for more details. │
│ │
│ You should have received a copy of the GNU General Public License │
│ along with this program; if not, write to the Free Software │
│ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA │
│ 02110-1301 USA │
╚─────────────────────────────────────────────────────────────────────────────*/
#include "libc/bits/popcnt.h"
#include "libc/calls/calls.h"
#include "libc/calls/struct/stat.h"
#include "libc/elf/elf.h"
#include "libc/elf/struct/phdr.h"
#include "libc/log/check.h"
#include "libc/log/log.h"
#include "libc/macros.h"
#include "libc/nexgen32e/vendor.internal.h"
#include "libc/runtime/runtime.h"
#include "libc/stdio/stdio.h"
#include "libc/sysv/consts/fileno.h"
#include "libc/sysv/consts/map.h"
#include "libc/sysv/consts/o.h"
#include "libc/sysv/consts/prot.h"
#include "tool/build/lib/argv.h"
#include "tool/build/lib/endian.h"
#include "tool/build/lib/loader.h"
#include "tool/build/lib/machine.h"
#include "tool/build/lib/memory.h"
static void LoadElfLoadSegment(struct Machine *m, void *code, size_t codesize,
Elf64_Phdr *phdr) {
void *rbss;
int64_t align, bsssize;
int64_t felf, fstart, fend, vstart, vbss, vend;
align = MAX(phdr->p_align, PAGESIZE);
CHECK_EQ(1, popcnt(align));
CHECK_EQ(0, (phdr->p_vaddr - phdr->p_offset) % align);
felf = (int64_t)(intptr_t)code;
vstart = ROUNDDOWN(phdr->p_vaddr, align);
vbss = ROUNDUP(phdr->p_vaddr + phdr->p_filesz, align);
vend = ROUNDUP(phdr->p_vaddr + phdr->p_memsz, align);
fstart = felf + ROUNDDOWN(phdr->p_offset, align);
fend = felf + phdr->p_offset + phdr->p_filesz;
bsssize = vend - vbss;
VERBOSEF("LOADELFLOADSEGMENT"
" VSTART %#lx VBSS %#lx VEND %#lx"
" FSTART %#lx FEND %#lx BSSSIZE %#lx",
vstart, vbss, vend, fstart, fend, bsssize);
m->brk = MAX(m->brk, vend);
CHECK_GE(vend, vstart);
CHECK_GE(fend, fstart);
CHECK_LE(felf, fstart);
CHECK_GE(vstart, -0x800000000000);
CHECK_LE(vend, 0x800000000000);
CHECK_GE(vend - vstart, fstart - fend);
CHECK_LE(phdr->p_filesz, phdr->p_memsz);
CHECK_EQ(felf + phdr->p_offset - fstart, phdr->p_vaddr - vstart);
CHECK_NE(-1, ReserveVirtual(m, vstart, fend - fstart, 0x0207));
VirtualRecv(m, vstart, (void *)fstart, fend - fstart);
if (bsssize) CHECK_NE(-1, ReserveVirtual(m, vbss, bsssize, 0x0207));
if (phdr->p_memsz - phdr->p_filesz > bsssize) {
VirtualSet(m, phdr->p_vaddr + phdr->p_filesz, 0,
phdr->p_memsz - phdr->p_filesz - bsssize);
}
}
static void LoadElf(struct Machine *m, struct Elf *elf) {
unsigned i;
Elf64_Phdr *phdr;
m->ip = elf->base = elf->ehdr->e_entry;
VERBOSEF("LOADELF ENTRY %p", m->ip);
for (i = 0; i < elf->ehdr->e_phnum; ++i) {
phdr = GetElfSegmentHeaderAddress(elf->ehdr, elf->size, i);
switch (phdr->p_type) {
case PT_LOAD:
elf->base = MIN(elf->base, phdr->p_vaddr);
LoadElfLoadSegment(m, elf->ehdr, elf->size, phdr);
break;
default:
break;
}
}
}
static void LoadBin(struct Machine *m, intptr_t base, const char *prog,
void *code, size_t codesize) {
Elf64_Phdr phdr = {
.p_type = PT_LOAD,
.p_flags = PF_X | PF_R | PF_W,
.p_offset = 0,
.p_vaddr = base,
.p_paddr = base,
.p_filesz = codesize,
.p_memsz = ROUNDUP(codesize + FRAMESIZE, BIGPAGESIZE),
.p_align = PAGESIZE,
};
LoadElfLoadSegment(m, code, codesize, &phdr);
m->ip = base;
}
static void BootProgram(struct Machine *m, struct Elf *elf, size_t codesize) {
m->ip = 0x7c00;
elf->base = 0x7c00;
CHECK_NE(-1, ReserveReal(m, 0x00f00000));
memset(m->real.p, 0, 0x00f00000);
Write16(m->real.p + 0x400, 0x3F8);
Write16(m->real.p + 0x40E, 0xb0000 >> 4);
Write16(m->real.p + 0x413, 0xb0000 / 1024);
Write16(m->real.p + 0x44A, 80);
Write64(m->cs, 0);
Write64(m->dx, 0);
memcpy(m->real.p + 0x7c00, elf->map, 512);
if (memcmp(elf->map, "\177ELF", 4) == 0) {
elf->ehdr = (void *)elf->map;
elf->size = codesize;
elf->base = elf->ehdr->e_entry;
} else {
elf->base = 0x7c00;
elf->ehdr = NULL;
elf->size = 0;
}
}
void LoadProgram(struct Machine *m, const char *prog, char **args, char **vars,
struct Elf *elf) {
int fd;
ssize_t rc;
int64_t sp;
struct stat st;
size_t i, mappedsize;
DCHECK_NOTNULL(prog);
elf->prog = prog;
if ((fd = open(prog, O_RDONLY)) == -1 ||
(fstat(fd, &st) == -1 || !st.st_size)) {
fputs(prog, stderr);
fputs(": not found\n", stderr);
exit(1);
}
elf->mapsize = st.st_size;
CHECK_NE(MAP_FAILED,
(elf->map = mmap(NULL, elf->mapsize, PROT_READ | PROT_WRITE,
MAP_PRIVATE, fd, 0)));
CHECK_NE(-1, close(fd));
ResetCpu(m);
if ((m->mode & 3) == XED_MODE_REAL) {
BootProgram(m, elf, elf->mapsize);
} else {
sp = 0x800000000000;
Write64(m->sp, sp);
m->cr3 = AllocateLinearPage(m);
CHECK_NE(-1, ReserveVirtual(m, sp - STACKSIZE, STACKSIZE, 0x0207));
LoadArgv(m, prog, args, vars);
if (memcmp(elf->map, "\177ELF", 4) == 0) {
elf->ehdr = (void *)elf->map;
elf->size = elf->mapsize;
LoadElf(m, elf);
} else {
elf->base = IMAGE_BASE_VIRTUAL;
elf->ehdr = NULL;
elf->size = 0;
LoadBin(m, elf->base, prog, elf->map, elf->mapsize);
}
}
}