misc: Add elsewhere TU and rework mb1 to use it

This commit is contained in:
mintsuki 2022-06-29 09:34:14 +02:00
parent e436b763c2
commit 19287d5ca1
6 changed files with 166 additions and 132 deletions

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@ -87,10 +87,4 @@ noreturn void common_spinup(void *fnptr, int args, ...);
#define no_unwind __attribute__((section(".no_unwind")))
struct elsewhere_range {
uint64_t elsewhere;
uint64_t target;
uint64_t length;
};
#endif

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@ -5,6 +5,7 @@
#include <lib/elf.h>
#include <lib/print.h>
#include <lib/rand.h>
#include <lib/elsewhere.h>
#include <mm/pmm.h>
#include <fs/file.h>

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@ -3,7 +3,7 @@
#include <stdint.h>
#include <stdbool.h>
#include <lib/blib.h>
#include <lib/elsewhere.h>
#define FIXED_HIGHER_HALF_OFFSET_64 ((uint64_t)0xffffffff80000000)

89
common/lib/elsewhere.c Normal file
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@ -0,0 +1,89 @@
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
#include <lib/elsewhere.h>
#include <lib/blib.h>
static bool elsewhere_overlap_check(uint64_t base1, uint64_t top1,
uint64_t base2, uint64_t top2) {
return ((base1 >= base2 && base1 < top2)
|| (top1 > base2 && top1 <= top2));
}
bool elsewhere_append(
bool flexible_target,
struct elsewhere_range *ranges, size_t *ranges_count,
void *elsewhere, uint64_t *target, size_t t_length) {
// original target of -1 means "allocate after top of all ranges"
// flexible target is ignored
flexible_target = true;
if (*target == (uint64_t)-1) {
uint64_t top = 0;
for (size_t i = 0; i < *ranges_count; i++) {
uint64_t r_top = ranges[i].target + ranges[i].length;
if (top < r_top) {
top = r_top;
}
}
*target = ALIGN_UP(top, 4096);
}
retry:
for (size_t i = 0; i < *ranges_count; i++) {
uint64_t t_top = *target + t_length;
// Does it overlap with other elsewhere ranges targets?
{
uint64_t base = ranges[i].target;
uint64_t length = ranges[i].length;
uint64_t top = base + length;
if (elsewhere_overlap_check(base, top, *target, t_top)) {
if (!flexible_target) {
return false;
}
*target = top;
goto retry;
}
}
// Does it overlap with other elsewhere ranges sources?
{
uint64_t base = ranges[i].elsewhere;
uint64_t length = ranges[i].length;
uint64_t top = base + length;
if (elsewhere_overlap_check(base, top, *target, t_top)) {
if (!flexible_target) {
return false;
}
*target += 0x1000;
goto retry;
}
}
// Make sure it is memory that actually exists.
if (!memmap_alloc_range(*target, t_length, MEMMAP_BOOTLOADER_RECLAIMABLE,
MEMMAP_USABLE, false, true, false)) {
if (!memmap_alloc_range(*target, t_length, MEMMAP_BOOTLOADER_RECLAIMABLE,
MEMMAP_BOOTLOADER_RECLAIMABLE, false, true, false)) {
if (!flexible_target) {
return false;
}
*target += 0x1000;
goto retry;
}
}
}
// Add the elsewhere range
ranges[*ranges_count].elsewhere = elsewhere;
ranges[*ranges_count].target = *target;
ranges[*ranges_count].length = t_length;
*ranges_count += 1;
return true;
}

19
common/lib/elsewhere.h Normal file
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@ -0,0 +1,19 @@
#ifndef __LIB__ELSEWHERE_H__
#define __LIB__ELSEWHERE_H__
#include <stdint.h>
#include <stddef.h>
#include <stdbool.h>
struct elsewhere_range {
uint64_t elsewhere;
uint64_t target;
uint64_t length;
};
bool elsewhere_append(
bool flexible_target,
struct elsewhere_range *ranges, size_t *ranges_count,
void *elsewhere, uint64_t *target, size_t t_length);
#endif

View File

@ -11,6 +11,7 @@
#include <lib/uri.h>
#include <lib/fb.h>
#include <lib/term.h>
#include <lib/elsewhere.h>
#include <sys/pic.h>
#include <sys/cpu.h>
#include <sys/idt.h>
@ -23,8 +24,6 @@ extern symbol multiboot_reloc_stub, multiboot_reloc_stub_end;
noreturn void multiboot1_spinup_32(uint32_t entry_point, uint32_t multiboot1_info);
static uint32_t kernel_top;
#define LIMINE_BRAND "Limine " LIMINE_VERSION
// Returns the size required to store the multiboot info.
@ -48,24 +47,6 @@ static void *mb1_info_alloc(void **mb1_info_raw, size_t size) {
return ret;
}
static bool mb1_overlap_check(uint64_t base1, uint64_t top1,
uint64_t base2, uint64_t top2) {
return ((base1 >= base2 && base1 < top2)
|| (top1 > base2 && top1 <= top2));
}
static void *mb1_alloc(size_t size) {
void *ret = (void *)(uintptr_t)ALIGN_UP(kernel_top, 4096);
while (!memmap_alloc_range((uintptr_t)ret, size, MEMMAP_KERNEL_AND_MODULES,
true, false, false, false)) {
ret += 0x200000;
}
kernel_top = (uintptr_t)ret + size;
return ret;
}
bool multiboot1_load(char *config, char *cmdline) {
struct file_handle *kernel_file;
@ -104,12 +85,11 @@ bool multiboot1_load(char *config, char *cmdline) {
if (header.magic + header.flags + header.checksum)
panic(true, "multiboot1: Header checksum is invalid");
uint32_t entry_point;
struct elf_section_hdr_info *section_hdr_info = NULL;
struct elf_range *elf_ranges;
uint64_t elf_ranges_count, slide = 0;
uint64_t entry_point;
struct elsewhere_range *ranges;
uint64_t ranges_count;
if (header.flags & (1 << 16)) {
if (header.load_addr > header.header_addr)
@ -132,66 +112,34 @@ bool multiboot1_load(char *config, char *cmdline) {
size_t full_size = load_size + bss_size;
bool simulation = true;
size_t try_count = 0;
size_t max_simulated_tries = 0x100000;
void *elsewhere = ext_mem_alloc(full_size);
retry_raw_load:;
uint64_t load_addr = header.load_addr + slide;
if (!memmap_alloc_range(load_addr, full_size, MEMMAP_BOOTLOADER_RECLAIMABLE, true, false, simulation, false)) {
if (simulation == false || ++try_count == max_simulated_tries) {
panic(true, "multiboot1: Failed to allocate necessary memory range (%X-%X)", load_addr, load_addr + full_size);
}
slide += 0x1000;
goto retry_raw_load;
}
if (simulation) {
simulation = false;
goto retry_raw_load;
}
memset((void *)(uintptr_t)load_addr, 0, full_size);
memcpy((void *)(uintptr_t)load_addr, kernel + (header_offset
memcpy(elsewhere, kernel + (header_offset
- (header.header_addr - header.load_addr)), load_size);
kernel_top = load_addr + full_size;
entry_point = header.entry_addr;
entry_point = header.entry_addr + slide;
ranges_count = 1;
ranges = ext_mem_alloc(sizeof(struct elsewhere_range));
elf_ranges_count = 1;
elf_ranges = ext_mem_alloc(sizeof(struct elf_range));
elf_ranges->base = load_addr;
elf_ranges->length = full_size;
ranges->elsewhere = elsewhere;
ranges->target = header.load_addr;
ranges->length = full_size;
} else {
int bits = elf_bits(kernel);
switch (bits) {
case 32:
if (!elf32_load_elsewhere(kernel, &entry_point, &ranges, &ranges_count))
panic(true, "multiboot1: ELF32 load failure");
section_hdr_info = elf32_section_hdr_info(kernel);
break;
case 64: {
section_hdr_info = elf64_section_hdr_info(kernel);
break;
}
}
switch (bits) {
case 32:
if (elf32_load(kernel, &entry_point, &kernel_top, MEMMAP_BOOTLOADER_RECLAIMABLE, &slide, &elf_ranges, &elf_ranges_count))
panic(true, "multiboot1: ELF32 load failure");
break;
case 64: {
uint64_t e, t;
if (elf64_load(kernel, &e, &t, &slide, MEMMAP_BOOTLOADER_RECLAIMABLE, false, true, &elf_ranges, &elf_ranges_count, false, NULL, NULL, NULL, NULL))
if (!elf64_load_elsewhere(kernel, &entry_point, &ranges, &ranges_count))
panic(true, "multiboot1: ELF64 load failure");
entry_point = e;
kernel_top = t;
section_hdr_info = elf64_section_hdr_info(kernel);
break;
}
default:
@ -199,13 +147,6 @@ retry_raw_load:;
}
}
entry_point -= slide;
kernel_top -= slide;
if (kernel_top < 0x100000) {
kernel_top = 0x100000;
}
size_t n_modules;
size_t modules_cmdlines_size = 0;
@ -226,44 +167,33 @@ retry_raw_load:;
section_hdr_info ? section_hdr_info->num : 0
);
// Realloc elsewhere ranges to include mb1 info, modules, and elf sections
struct elsewhere_range *new_ranges = ext_mem_alloc(sizeof(struct elsewhere_range) *
(ranges_count
+ 1 /* mb1 info range */
+ n_modules,
+ section_hdr_info ? section_hdr_info->num : 0));
memcpy(new_ranges, ranges, sizeof(struct elsewhere_range) * ranges_count);
pmm_free(ranges, sizeof(struct elsewhere_range) * ranges_count);
ranges = new_ranges;
// GRUB allocates boot info at 0x10000, *except* if the kernel happens
// to overlap this region, then it gets moved to right after the
// kernel, or whichever PHDR happens to sit at 0x10000.
// Allocate it wherever, then move it to where GRUB puts it
// afterwards.
// Elsewhere append mb1 info *after* kernel but *before* modules.
void *mb1_info_raw = ext_mem_alloc(mb1_info_size);
uint64_t mb1_info_final_loc = 0x10000;
retry_mb1_info_reloc:
for (size_t i = 0; i < elf_ranges_count; i++) {
uint64_t mb1_info_top = mb1_info_final_loc + mb1_info_size;
uint64_t base = elf_ranges[i].base - slide;
uint64_t length = elf_ranges[i].length;
uint64_t top = base + length;
// Do they overlap?
if (mb1_overlap_check(base, top, mb1_info_final_loc, mb1_info_top)) {
mb1_info_final_loc = top;
goto retry_mb1_info_reloc;
}
// Make sure it is memory that actually exists.
if (!memmap_alloc_range(mb1_info_final_loc, mb1_info_size, MEMMAP_BOOTLOADER_RECLAIMABLE,
MEMMAP_USABLE, false, true, false)) {
if (!memmap_alloc_range(mb1_info_final_loc, mb1_info_size, MEMMAP_BOOTLOADER_RECLAIMABLE,
MEMMAP_BOOTLOADER_RECLAIMABLE, false, true, false)) {
mb1_info_final_loc += 0x1000;
goto retry_mb1_info_reloc;
}
}
}
elsewhere_append(true /* flexible target */,
ranges, &ranges_count,
mb1_info_raw, &mb1_info_final_loc, mb1_info_size);
size_t mb1_info_slide = (size_t)mb1_info_raw - mb1_info_final_loc;
if (mb1_info_final_loc + mb1_info_size > kernel_top) {
kernel_top = mb1_info_final_loc + mb1_info_size;
}
struct multiboot1_info *multiboot1_info =
mb1_info_alloc(&mb1_info_raw, sizeof(struct multiboot1_info));
@ -286,10 +216,13 @@ retry_mb1_info_reloc:
continue;
}
void *section = mb1_alloc(shdr->sh_size);
memcpy(section, kernel + shdr->sh_offset, shdr->sh_size);
uint64_t section = (uint64_t)-1; /* no target preference, use top */
shdr->sh_addr = (uintptr_t)section;
elsewhere_append(true /* flexible target */,
ranges, &ranges_count,
kernel + shdr->sh_offset, &section, shdr->sh_size);
shdr->sh_addr = section;
}
multiboot1_info->flags |= (1 << 5);
@ -323,11 +256,14 @@ retry_mb1_info_reloc:
char *lowmem_modstr = mb1_info_alloc(&mb1_info_raw, strlen(module_cmdline) + 1);
strcpy(lowmem_modstr, module_cmdline);
void *module_addr = mb1_alloc(f->size);
void *module_addr = freadall(f);
uint64_t module_target = (uint64_t)-1; /* no target preference, use top */
fread(f, module_addr, 0, f->size);
elsewhere_append(true /* flexible target */,
ranges, &ranges_count,
module_addr, &module_target, f->size);
m->begin = (uint32_t)(size_t)module_addr;
m->begin = module_target;
m->end = m->begin + f->size;
m->cmdline = (uint32_t)(size_t)lowmem_modstr - mb1_info_slide;
m->pad = 0;
@ -417,9 +353,9 @@ nofb:;
#endif
}
// Load relocation stub where it won't get overwritten
// Load relocation stub where it won't get overwritten (hopefully)
size_t reloc_stub_size = (size_t)multiboot_reloc_stub_end - (size_t)multiboot_reloc_stub;
void *reloc_stub = mb1_alloc(reloc_stub_size);
void *reloc_stub = ext_mem_alloc(reloc_stub_size);
memcpy(reloc_stub, multiboot_reloc_stub, reloc_stub_size);
#if uefi == 1
@ -440,14 +376,13 @@ nofb:;
mmap[i].type = raw_memmap[i].type;
}
{
struct meminfo memory_info = mmap_get_info(mb_mmap_count, raw_memmap);
// Convert the uppermem and lowermem fields from bytes to
// KiB.
multiboot1_info->mem_lower = memory_info.lowermem / 1024;
multiboot1_info->mem_upper = memory_info.uppermem / 1024;
}
struct meminfo memory_info = mmap_get_info(mb_mmap_count, raw_memmap);
// Convert the uppermem and lowermem fields from bytes to
// KiB.
multiboot1_info->mem_lower = memory_info.lowermem / 1024;
multiboot1_info->mem_upper = memory_info.uppermem / 1024;
multiboot1_info->mmap_length = mb_mmap_len;
multiboot1_info->mmap_addr = (uint32_t)(size_t)mmap - mb1_info_slide;
@ -455,11 +390,7 @@ nofb:;
irq_flush_type = IRQ_PIC_ONLY_FLUSH;
common_spinup(multiboot1_spinup_32, 8,
entry_point,
(uint32_t)(uintptr_t)multiboot1_info, (uint32_t)mb1_info_final_loc,
(uint32_t)mb1_info_size,
(uint32_t)(uintptr_t)elf_ranges, (uint32_t)elf_ranges_count,
(uint32_t)slide,
(uint32_t)(uintptr_t)reloc_stub);
common_spinup(multiboot_spinup_32, 4,
0x2badb002, entry_point,
(uint32_t)(uintptr_t)ranges, (uint32_t)ranges_count);
}