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multiboot: Backport b92d48e to multiboot1

This commit is contained in:
mintsuki 2022-06-27 11:17:47 +02:00
parent b92d48e44f
commit b9400d2fc9
4 changed files with 100 additions and 32 deletions
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13
common/protos/multiboot.h Normal file
View File

@ -0,0 +1,13 @@
#ifndef __PROTOS__MULTIBOOT_H__
#define __PROTOS__MULTIBOOT_H__
#include <stdint.h>
struct mb_reloc_stub {
char jmp[4];
uint32_t magic;
uint32_t entry_point;
uint32_t mb_info_target;
};
#endif

30
common/protos/multiboot1.32.c
View File

@ -6,8 +6,14 @@
#if bios == 1
# include <sys/idt.h>
#endif
#include <protos/multiboot.h>
noreturn void multiboot1_spinup_32(uint32_t entry_point, uint32_t multiboot1_info) {
noreturn void multiboot1_spinup_32(uint32_t entry_point,
uint32_t multiboot1_info, uint32_t mb_info_target,
uint32_t mb_info_size,
uint32_t elf_ranges, uint32_t elf_ranges_count,
uint32_t slide,
struct mb_reloc_stub *reloc_stub) {
#if bios == 1
struct idtr idtr;
@ -22,22 +28,16 @@ noreturn void multiboot1_spinup_32(uint32_t entry_point, uint32_t multiboot1_inf
);
#endif
reloc_stub->magic = 0x2badb002;
reloc_stub->entry_point = entry_point;
reloc_stub->mb_info_target = mb_info_target;
asm volatile (
"cld\n\t"
"push %2\n\t"
"xor %%ecx, %%ecx\n\t"
"xor %%edx, %%edx\n\t"
"xor %%esi, %%esi\n\t"
"xor %%edi, %%edi\n\t"
"xor %%ebp, %%ebp\n\t"
"ret\n\t"
"jmp *%%ebx"
:
: "a" (0x2badb002),
"b" (multiboot1_info),
"r" (entry_point)
: "b"(reloc_stub), "S"(multiboot1_info),
"c"(mb_info_size), "a"(elf_ranges), "d"(elf_ranges_count),
"D"(slide)
: "memory"
);

79
common/protos/multiboot1.c
View File

@ -19,10 +19,18 @@
#include <mm/pmm.h>
#include <drivers/vga_textmode.h>
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;
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);
@ -70,8 +78,6 @@ bool multiboot1_load(char *config, char *cmdline) {
print("multiboot1: Loading kernel `%s`...\n", kernel_path);
struct multiboot1_info *multiboot1_info = conv_mem_alloc(sizeof(struct multiboot1_info));
if (header.magic + header.flags + header.checksum)
panic(true, "multiboot1: Header checksum is invalid");
@ -79,6 +85,9 @@ bool multiboot1_load(char *config, char *cmdline) {
struct elf_section_hdr_info *section_hdr_info = NULL;
struct elf_range *elf_ranges;
uint64_t elf_ranges_count, slide;
if (header.flags & (1 << 16)) {
if (header.load_addr > header.header_addr)
panic(true, "multiboot1: Illegal load address");
@ -125,15 +134,21 @@ bool multiboot1_load(char *config, char *cmdline) {
switch (bits) {
case 32:
if (elf32_load(kernel, &entry_point, &kernel_top, MEMMAP_KERNEL_AND_MODULES))
if (elf32_load(kernel, &entry_point, &kernel_top, MEMMAP_BOOTLOADER_RECLAIMABLE))
panic(true, "multiboot1: ELF32 load failure");
break;
case 64: {
uint64_t e, t;
if (elf64_load(kernel, &e, &t, NULL, MEMMAP_KERNEL_AND_MODULES, false, true, NULL, NULL, false, NULL, NULL, NULL, NULL))
if (elf64_load(kernel, &e, &t, &slide, MEMMAP_BOOTLOADER_RECLAIMABLE, false, true, &elf_ranges, &elf_ranges_count, false, NULL, NULL, NULL, NULL))
panic(true, "multiboot1: ELF64 load failure");
entry_point = e;
kernel_top = t;
entry_point = e - slide;
t -= slide;
if (t < 0x100000) {
kernel_top = 0x100000;
} else {
kernel_top = t;
}
break;
}
@ -142,6 +157,43 @@ bool multiboot1_load(char *config, char *cmdline) {
}
}
// 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.
size_t mb1_info_size = sizeof(struct multiboot1_info);
struct multiboot1_info *multiboot1_info = 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 - slide;
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;
}
}
}
if (mb1_info_final_loc + mb1_info_size > kernel_top) {
kernel_top = mb1_info_final_loc + mb1_info_size;
}
if (section_hdr_info != NULL) {
multiboot1_info->elf_sect.num = section_hdr_info->num;
multiboot1_info->elf_sect.size = section_hdr_info->section_entry_size;
@ -169,7 +221,6 @@ bool multiboot1_load(char *config, char *cmdline) {
multiboot1_info->flags |= (1 << 5);
}
uint32_t n_modules;
for (n_modules = 0; ; n_modules++) {
@ -298,6 +349,11 @@ nofb:;
#endif
}
// Load relocation stub where it won't get overwritten
size_t reloc_stub_size = (size_t)multiboot_reloc_stub_end - (size_t)multiboot_reloc_stub;
void *reloc_stub = mb1_alloc(reloc_stub_size);
memcpy(reloc_stub, multiboot_reloc_stub, reloc_stub_size);
#if uefi == 1
efi_exit_boot_services();
#endif
@ -331,6 +387,11 @@ nofb:;
irq_flush_type = IRQ_PIC_ONLY_FLUSH;
common_spinup(multiboot1_spinup_32, 2,
entry_point, (uint32_t)(uintptr_t)multiboot1_info);
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);
}

10
common/protos/multiboot2.32.c
View File

@ -6,20 +6,14 @@
#if bios == 1
# include <sys/idt.h>
#endif
struct reloc_stub {
char jmp[4];
uint32_t magic;
uint32_t entry_point;
uint32_t mb_info_target;
};
#include <protos/multiboot.h>
noreturn void multiboot2_spinup_32(uint32_t entry_point,
uint32_t multiboot2_info, uint32_t mb_info_target,
uint32_t mb_info_size,
uint32_t elf_ranges, uint32_t elf_ranges_count,
uint32_t slide,
struct reloc_stub *reloc_stub) {
struct mb_reloc_stub *reloc_stub) {
#if bios == 1
struct idtr idtr;