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Get binaries closer to running without an o/s

Browse source 
blinkenlights now does a pretty good job emulating what happens when
binaries boot from BIOS into long mode. So it's been much easier to
debug the bare metal process and wrinkle out many issues.
This commit is contained in:
Justine Tunney 2020-10-29 04:53:20 -07:00
parent feed0d2b0e
commit 2d80bbc802
50 changed files with 974 additions and 1062 deletions
Download patch file Download diff file Expand all files Collapse all files

12
ape/lib/getpagetableentry.c
View file

@ -24,14 +24,16 @@ textreal static uint64_t pushpagetable(uint64_t *ptsp) {
return (*ptsp -= PAGESIZE) | PAGE_V | PAGE_RW;
}
textreal uint64_t *getpagetableentry(uint64_t vaddr, unsigned depth,
textreal uint64_t *getpagetableentry(int64_t vaddr, unsigned depth,
struct PageTable *pml4t, uint64_t *ptsp) {
uint64_t *entry;
unsigned char shift;
assert(depth <= 3);
assert(*ptsp % PAGESIZE == 0);
assert((intptr_t)pml4t % PAGESIZE == 0);
unsigned char shift = 39;
assert(!(*ptsp & 0xfff));
assert(!((uintptr_t)pml4t & 0xfff));
shift = 39;
for (;;) {
uint64_t *entry = &pml4t->p[(vaddr >> shift) & 511];
entry = &pml4t->p[(vaddr >> shift) & 511];
if (!depth--) return entry;
shift -= 9;
if (!*entry) *entry = pushpagetable(ptsp);

2
ape/lib/kbiosdataarea.S
View file

@ -37,7 +37,7 @@
.size kBiosDataAreaXlm,XLM_BIOS_DATA_AREA_SIZE
kBiosDataAreaXlm = XLM(BIOS_DATA_AREA)
.section .sort.real.init.2.kBiosDataArea,"ax",@progbits
.section .sort.text.real.init.2.kBiosDataArea,"ax",@progbits
movpp %ds,%es # copy bios data to valid page
mov $PC_BIOS_DATA_AREA,%si
mov $XLM(BIOS_DATA_AREA),%di

38
ape/lib/mapimage.c Normal file
View file

@ -0,0 +1,38 @@
/*-*- 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 "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_PHYSICAL + a) | k;
}
}
textreal void __map_image(void) {
pageunmap(0);
__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);
}

5
ape/lib/pageunmap.c
View file

@ -20,8 +20,9 @@
#include "ape/lib/pc.h"
#include "libc/bits/bits.h"
textreal void pageunmap(uint64_t vaddr) {
uint64_t *entry = getpagetableentry(vaddr, 3, &g_pml4t, &g_ptsp_xlm);
textreal void pageunmap(int64_t vaddr) {
uint64_t *entry;
entry = getpagetableentry(vaddr, 3, &g_pml4t, &g_ptsp_xlm);
*entry &= ~PAGE_V;
invlpg(vaddr);
}

5
ape/lib/pc.h
View file

@ -157,6 +157,7 @@
#define PAGE_1GB /* */ 0b110000000
#define PAGE_TA 0b11111111111111111111111111111111111111000000000000
#define PAGE_PA2 0b11111111111111111111111111111000000000000000000000
#define PAGE_XD 0x8000000000000000
#if !(__ASSEMBLER__ + __LINKER__ + 0)
#include "ape/config.h"
@ -213,9 +214,9 @@ extern uint64_t g_ptsp_xlm;
void bootdr(char drive) noreturn;
void smapsort(struct SmapEntry *);
uint64_t *getpagetableentry(uint64_t, unsigned, struct PageTable *, uint64_t *);
uint64_t *getpagetableentry(int64_t, unsigned, struct PageTable *, uint64_t *);
void flattenhighmemory(struct SmapEntry *, struct PageTable *, uint64_t *);
void pageunmap(uint64_t);
void pageunmap(int64_t);
forceinline unsigned long eflags(void) {
unsigned long res;