:: commit 33692555a7fc2a1c7c79c4e23bb4744bd9abd8bd
multiboot2: Add support for a.out kludge and other enhancements
diff --git a/stage23/protos/multiboot2.c b/stage23/protos/multiboot2.c
index e0071a75..7d5e4e95 100644
--- a/stage23/protos/multiboot2.c
+++ b/stage23/protos/multiboot2.c
@@ -20,7 +20,6 @@
static struct multiboot_header *load_multiboot2_header(uint8_t *kernel) {
struct multiboot_header *ptr = NULL;
- struct multiboot_header header;
size_t header_offset;
@@ -29,11 +28,7 @@ static struct multiboot_header *load_multiboot2_header(uint8_t *kernel) {
memcpy(&v, kernel + header_offset, 4);
if (v == MULTIBOOT2_HEADER_MAGIC) {
- memcpy(&header, kernel + header_offset, sizeof(header));
-
- ptr = ext_mem_alloc(header.header_length);
- memcpy(ptr, kernel + header_offset, header.header_length);
-
+ ptr = (void *)(kernel + header_offset);
break;
}
}
@@ -53,14 +48,14 @@ static struct multiboot_header *load_multiboot2_header(uint8_t *kernel) {
static size_t get_multiboot2_info_size(
char *cmdline,
size_t modules_size,
- struct elf_section_hdr_info *section_hdr_info
+ uint32_t section_hdr_size
) {
return ALIGN_UP(sizeof(struct multiboot2_start_tag), MULTIBOOT_TAG_ALIGN) + // start
ALIGN_UP(strlen(cmdline) + 1 + offsetof(struct multiboot_tag_string, string), MULTIBOOT_TAG_ALIGN) + // cmdline
ALIGN_UP(8 + offsetof(struct multiboot_tag_string, string), MULTIBOOT_TAG_ALIGN) + // bootloader brand
ALIGN_UP(sizeof(struct multiboot_tag_framebuffer), MULTIBOOT_TAG_ALIGN) + // framebuffer
ALIGN_UP(sizeof(struct multiboot_tag_new_acpi) + 36, MULTIBOOT_TAG_ALIGN) + // new ACPI info
- ALIGN_UP(sizeof(struct multiboot_tag_elf_sections) + section_hdr_info->section_hdr_size, MULTIBOOT_TAG_ALIGN) + // ELF info
+ ALIGN_UP(sizeof(struct multiboot_tag_elf_sections) + section_hdr_size, MULTIBOOT_TAG_ALIGN) + // ELF info
ALIGN_UP(modules_size, MULTIBOOT_TAG_ALIGN) + // modules
ALIGN_UP(sizeof(struct multiboot_tag_mmap) + sizeof(struct multiboot_mmap_entry) * 256, MULTIBOOT_TAG_ALIGN) + // MMAP
#if uefi == 1
@@ -86,38 +81,12 @@ void multiboot2_load(char *config, char* cmdline) {
uint8_t *kernel = freadall(kernel_file, MEMMAP_KERNEL_AND_MODULES);
struct multiboot_header *header = load_multiboot2_header(kernel);
- uint32_t entry_point;
- uint32_t kernel_top;
-
- int bits = elf_bits(kernel);
- struct elf_section_hdr_info *section_hdr_info;
-
- switch (bits) {
- case 32:
- section_hdr_info = elf32_section_hdr_info(kernel);
-
- if (elf32_load(kernel, &entry_point, &kernel_top, MEMMAP_KERNEL_AND_MODULES))
- panic("multiboot2: ELF32 load failure");
-
- break;
- case 64: {
- section_hdr_info = elf64_section_hdr_info(kernel);
-
- uint64_t e, t;
- if (elf64_load(kernel, &e, &t, NULL, MEMMAP_KERNEL_AND_MODULES, false, true, NULL, NULL))
- panic("multiboot2: ELF64 load failure");
-
- entry_point = e;
- kernel_top = t;
-
- break;
- }
- default:
- panic("multiboot2: invalid ELF file bitness");
- }
-
+ struct multiboot_header_tag_address *addresstag = NULL;
struct multiboot_header_tag_framebuffer *fbtag = NULL;
bool is_new_acpi_required = false;
+ bool is_elf_info_requested = false;
+
+ uint32_t entry_point = 0xffffffff;
// Iterate through the entries...
for (struct multiboot_header_tag *tag = (struct multiboot_header_tag*)(header + 1); // header + 1 to skip the header struct.
@@ -126,12 +95,12 @@ void multiboot2_load(char *config, char* cmdline) {
switch (tag->type) {
case MULTIBOOT_HEADER_TAG_INFORMATION_REQUEST: {
// Iterate the requests and check if they are supported by or not.
- struct multiboot_header_tag_information_request *request = (void*)tag;
+ struct multiboot_header_tag_information_request *request = (void *)tag;
uint32_t size = (request->size - sizeof(struct multiboot_header_tag_information_request)) / sizeof(uint32_t);
+ bool is_required = !(request->flags & MULTIBOOT_HEADER_TAG_OPTIONAL);
for (uint32_t i = 0; i < size; i++) {
uint32_t r = request->requests[i];
- bool is_required = !(tag->flags & MULTIBOOT_HEADER_TAG_OPTIONAL);
switch (r) {
// We already support the following requests:
@@ -141,13 +110,15 @@ void multiboot2_load(char *config, char* cmdline) {
case MULTIBOOT_TAG_TYPE_MMAP:
case MULTIBOOT_TAG_TYPE_EFI_MMAP:
case MULTIBOOT_TAG_TYPE_FRAMEBUFFER:
- case MULTIBOOT_TAG_TYPE_ELF_SECTIONS:
break;
case MULTIBOOT_TAG_TYPE_ACPI_NEW:
is_new_acpi_required = is_required;
break;
+ case MULTIBOOT_TAG_TYPE_ELF_SECTIONS:
+ is_elf_info_requested = is_required;
+ break;
default:
- if (!(request->flags & MULTIBOOT_HEADER_TAG_OPTIONAL))
+ if (is_required)
panic("multiboot2: Requested tag `%d` which is not supported", r);
break;
}
@@ -155,7 +126,16 @@ void multiboot2_load(char *config, char* cmdline) {
break;
}
case MULTIBOOT_HEADER_TAG_FRAMEBUFFER: {
- fbtag = (struct multiboot_header_tag_framebuffer *)tag;
+ fbtag = (void *)tag;
+ break;
+ }
+ case MULTIBOOT_HEADER_TAG_ENTRY_ADDRESS: {
+ struct multiboot_header_tag_entry_address *entrytag = (void *)tag;
+ entry_point = entrytag->entry_addr;
+ break;
+ }
+ case MULTIBOOT_HEADER_TAG_ADDRESS: {
+ addresstag = (void *)tag;
break;
}
// We always align the modules ;^)
@@ -165,6 +145,78 @@ void multiboot2_load(char *config, char* cmdline) {
}
}
+ uint32_t kernel_top;
+
+ if (addresstag != NULL) {
+ if (addresstag->load_addr > addresstag->header_addr)
+ panic("multiboot2: Illegal load address");
+
+ size_t load_size = 0;
+
+ if (addresstag->load_end_addr)
+ load_size = addresstag->load_end_addr - addresstag->load_addr;
+ else
+ load_size = kernel_file->size;
+
+ size_t header_offset = (size_t)header - (size_t)kernel;
+
+ memmap_alloc_range(addresstag->load_addr, load_size, MEMMAP_KERNEL_AND_MODULES, true, true, false, false);
+ memcpy((void *)(uintptr_t)addresstag->load_addr, kernel + (header_offset
+ - (addresstag->header_addr - addresstag->load_addr)), load_size);
+
+ kernel_top = addresstag->load_addr + load_size;
+
+ if (addresstag->bss_end_addr) {
+ uintptr_t bss_addr = addresstag->load_addr + load_size;
+ if (addresstag->bss_end_addr < bss_addr)
+ panic("multiboot2: Illegal bss end address");
+
+ uint32_t bss_size = addresstag->bss_end_addr - bss_addr;
+
+ memmap_alloc_range(bss_addr, bss_size, MEMMAP_KERNEL_AND_MODULES, true, true, false, false);
+ memset((void *)bss_addr, 0, bss_size);
+
+ kernel_top = bss_addr + bss_size;
+ }
+ } else {
+ int bits = elf_bits(kernel);
+ uint64_t e = 0, t = 0;
+
+ switch (bits) {
+ case 32:
+ if (elf32_load(kernel, (uint32_t *)&e, (uint32_t *)&t, MEMMAP_KERNEL_AND_MODULES))
+ panic("multiboot2: ELF32 load failure");
+
+ break;
+ case 64: {
+ if (elf64_load(kernel, &e, &t, NULL, MEMMAP_KERNEL_AND_MODULES, false, true, NULL, NULL))
+ panic("multiboot2: ELF64 load failure");
+
+ break;
+ }
+ default:
+ panic("multiboot2: Invalid ELF file bitness");
+ }
+
+ if (entry_point == 0xffffffff) {
+ entry_point = e;
+ }
+ kernel_top = t;
+ }
+
+ struct elf_section_hdr_info *section_hdr_info = NULL;
+ int bits = elf_bits(kernel);
+
+ switch (bits) {
+ case 32:
+ section_hdr_info = elf32_section_hdr_info(kernel);
+ break;
+ case 64: {
+ section_hdr_info = elf64_section_hdr_info(kernel);
+ break;
+ }
+ }
+
size_t modules_size = 0;
size_t n_modules;
@@ -180,7 +232,7 @@ void multiboot2_load(char *config, char* cmdline) {
modules_size += sizeof(struct multiboot_tag_module) + strlen(module_cmdline) + 1;
}
- size_t mb2_info_size = get_multiboot2_info_size(cmdline, modules_size, section_hdr_info);
+ size_t mb2_info_size = get_multiboot2_info_size(cmdline, modules_size, section_hdr_info ? section_hdr_info->section_hdr_size : 0);
size_t info_idx = 0;
uint8_t *mb2_info = conv_mem_alloc(mb2_info_size);
@@ -348,18 +400,24 @@ void multiboot2_load(char *config, char* cmdline) {
// Create ELF info tag
//////////////////////////////////////////////
{
- uint32_t size = sizeof(struct multiboot_tag_elf_sections) + section_hdr_info->section_hdr_size;
- struct multiboot_tag_elf_sections *tag = (struct multiboot_tag_elf_sections*)(mb2_info + info_idx);
+ if (section_hdr_info == NULL) {
+ if (is_elf_info_requested) {
+ panic("multiboot2: Cannot return ELF file information");
+ }
+ } else {
+ uint32_t size = sizeof(struct multiboot_tag_elf_sections) + section_hdr_info->section_hdr_size;
+ struct multiboot_tag_elf_sections *tag = (struct multiboot_tag_elf_sections*)(mb2_info + info_idx);
- tag->type = MULTIBOOT_TAG_TYPE_ELF_SECTIONS;
- tag->size = size;
+ tag->type = MULTIBOOT_TAG_TYPE_ELF_SECTIONS;
+ tag->size = size;
- tag->num = section_hdr_info->num;
- tag->entsize = section_hdr_info->section_entry_size;
- tag->shndx = section_hdr_info->str_section_idx;
+ tag->num = section_hdr_info->num;
+ tag->entsize = section_hdr_info->section_entry_size;
+ tag->shndx = section_hdr_info->str_section_idx;
- memcpy(tag->sections, section_hdr_info->section_hdrs, section_hdr_info->section_hdr_size);
- append_tag(info_idx, tag);
+ memcpy(tag->sections, section_hdr_info->section_hdrs, section_hdr_info->section_hdr_size);
+ append_tag(info_idx, tag);
+ }
}
#if uefi == 1
