/**
* Get the PXE entry point address.
*
* @return Whether the entry point could be found.
*/
static bool get_entry_point(void) {
bios_regs_t regs;
pxenv_t *pxenv;
pxe_t *pxe;
/* Use the PXE installation check function. */
bios_regs_init(®s);
regs.eax = INT1A_PXE_INSTALL_CHECK;
bios_call(0x1a, ®s);
if (regs.eax != INT1A_PXE_INSTALL_CHECK_RET || regs.eflags & X86_FLAGS_CF) {
dprintf("pxe: loaded via PXE but PXE not available\n");
return false;
}
/* Get the PXENV+ structure. */
pxenv = (pxenv_t *)segoff_to_linear((regs.es << 16) | regs.bx);
if (memcmp(pxenv->signature, PXENV_SIGNATURE, sizeof(pxenv->signature)) != 0) {
boot_error("PXENV+ structure has incorrect signature");
} else if (!checksum_range(pxenv, pxenv->length)) {
boot_error("PXENV+ structure is corrupt");
}
/* Get the !PXE structure. */
pxe = (pxe_t *)segoff_to_linear(pxenv->pxe_ptr);
if (memcmp(pxe->signature, PXE_SIGNATURE, sizeof(pxe->signature)) != 0) {
boot_error("!PXE structure has incorrect signature");
} else if (!checksum_range(pxe, pxe->length)) {
boot_error("!PXE structure is corrupt");
}
pxe_entry_point = pxe->entry_point_16;
return true;
}
/** Load an EFI executable.
* @param _loader Pointer to loader data. */
static __noreturn void efi_loader_load(void *_loader) {
efi_loader_t *loader = _loader;
void *buf;
efi_handle_t image_handle;
efi_loaded_image_t *image;
efi_char16_t *str;
efi_uintn_t str_size;
efi_status_t status;
status_t ret;
/* Allocate a buffer to read the image into. */
buf = malloc_large(loader->handle->size);
/* Read it in. */
ret = fs_read(loader->handle, buf, loader->handle->size, 0);
if (ret != STATUS_SUCCESS)
boot_error("Error reading EFI image: %pS", ret);
/* Ask the firmware to load the image. */
status = efi_call(
efi_boot_services->load_image,
false, efi_image_handle, NULL, buf, loader->handle->size, &image_handle);
if (status != EFI_SUCCESS)
boot_error("Error loading EFI image (0x%zx)", status);
/* Get the loaded image protocol. */
status = efi_get_loaded_image(image_handle, &image);
if (status != EFI_SUCCESS)
boot_error("Error getting loaded image protocol (0x%zx)", status);
/* Try to identify the handle of the device the image was on. */
image->device_handle = efi_device_get_handle(loader->handle->mount->device);
image->file_path = loader->efi_path;
fs_close(loader->handle);
/* Convert the arguments to UTF-16. FIXME: UTF-8 internally? */
str_size = (strlen(loader->args.string) + 1) * sizeof(*str);
str = malloc(str_size);
for (size_t i = 0; i < str_size / sizeof(*str); i++)
str[i] = loader->args.string[i];
image->load_options = str;
image->load_options_size = str_size;
loader_preboot();
/* Free up extra memory we've allocated. */
efi_memory_cleanup();
/* Start the image. */
status = efi_call(efi_boot_services->start_image, image_handle, &str_size, &str);
if (status != EFI_SUCCESS)
dprintf("efi: loaded image returned status 0x%zx\n", status);
/* We can't do anything here - the loaded image may have done things making
* our internal state invalid. Just pass through the error to whatever
* loaded us. */
efi_exit(status, str, str_size);
}
/** Perform architecture-specific setup tasks.
* @param loader LAOS loader data structure. */
void laos_arch_setup(laos_loader_t *loader) {
laos_tag_pagetables_t *tag;
target_ptr_t virt;
uint32_t *l1, *l2;
phys_ptr_t phys;
/* Allocate a 1MB temporary mapping region for the kernel. */
if(!allocator_alloc(&loader->alloc, 0x100000, 0x100000, &virt))
boot_error("Unable to allocate temporary mapping region");
/* Create a second level table to cover the region. */
phys_memory_alloc(PAGE_SIZE, PAGE_SIZE, 0, 0, PHYS_MEMORY_PAGETABLES, 0, &phys);
memset((void *)phys, 0, PAGE_SIZE);
/* Insert it into the first level table, then point its last entry to
* itself. */
l1 = (uint32_t *)loader->mmu->l1;
l1[virt / 0x100000] = phys | (1<<0);
l2 = (uint32_t *)phys;
l2[255] = phys | (1<<1) | (1<<4);
/* Add the pagetables tag. */
tag = laos_allocate_tag(loader, LAOS_TAG_PAGETABLES, sizeof(*tag));
tag->l1 = loader->mmu->l1;
tag->mapping = virt;
}
/**
* Get the BOOTP reply packet.
*
* @return Pointer to BOOTP reply packet.
*/
static bootp_packet_t *get_bootp_packet(void) {
pxenv_get_cached_info_t ci;
/* Obtain the BOOTP reply packet. */
ci.packet_type = PXENV_PACKET_TYPE_CACHED_REPLY;
ci.buffer = 0;
ci.buffer_size = 0;
if (pxe_call(PXENV_GET_CACHED_INFO, &ci) != PXENV_EXIT_SUCCESS)
boot_error("Failed to get PXE BOOTP packet (0x%x)", ci.status);
return (bootp_packet_t *)segoff_to_linear(ci.buffer);
}
/**
* Handle a configuration error.
*
* The action of this function depends on whether the error results from an
* error in a configuration file, or if being executed from the shell. If the
* error is in the file, the function will display an error UI and not return.
* If the error occurred in the shell, it will print the error message to the
* console and return.
*
* @param fmt Format string used to create the error message.
* @param ... Arguments to substitute into format.
*/
void config_error(const char *fmt, ...) {
va_list args;
const char *cmd;
va_start(args, fmt);
/* Set current_command to NULL so that it will not be set if the handler
* calls boot_error() and then the user goes into the shell. */
cmd = current_command;
current_command = NULL;
if (current_error_handler) {
current_error_handler(cmd, fmt, args);
} else {
vsnprintf(temp_buf, TEMP_BUF_LEN, fmt, args);
boot_error("%s", temp_buf);
}
va_end(args);
}
/** Check a kernel image and determine the target type.
* @param loader LAOS loader data structure. */
void laos_arch_check(laos_loader_t *loader) {
if(!elf_check(loader->kernel, ELFCLASS32, ELFDATA2LSB, ELF_EM_ARM))
boot_error("Kernel image is not for this architecture");
loader->target = TARGET_TYPE_32BIT;
}
/**
* Load an x86 Linux kernel.
*
* @param loader Loader internal data.
*/
__noreturn void linux_arch_load(linux_loader_t *loader)
{
linux_params_t *params;
size_t cmdline_size, setup_size, load_size;
char *cmdline;
void *virt;
phys_ptr_t phys, initrd_max;
list_t memory_map;
status_t ret;
static_assert(sizeof(linux_params_t) == PAGE_SIZE);
static_assert(offsetof(linux_params_t, hdr) == LINUX_HEADER_OFFSET);
// Allocate memory for the parameters data (the "zero page").
params = memory_alloc(sizeof(linux_params_t), 0, 0x10000, 0x90000, MEMORY_TYPE_RECLAIMABLE, 0, NULL);
memset(params, 0, sizeof(*params));
// Read in the kernel header.
ret = fs_read(loader->kernel, ¶ms->hdr, sizeof(params->hdr), offsetof(linux_params_t, hdr));
if (ret != STATUS_SUCCESS)
boot_error("Error reading kernel header: %pS", ret);
// Start populating required fields in the header. Don't set heap_end_ptr or
// the CAN_USE_HEAP flag, as these appear to only be required by the 16-bit
// entry point which we do not use.
params->hdr.type_of_loader = 0xff;
// Calculate the maximum command line size.
cmdline_size = (params->hdr.version >= 0x0206) ? params->hdr.cmdline_size : 255;
if (strlen(loader->cmdline) > cmdline_size)
boot_error("Kernel command line is too long");
// Allocate memory for command line.
cmdline_size = round_up(cmdline_size + 1, PAGE_SIZE);
cmdline = memory_alloc(cmdline_size, 0, 0x10000, 0x90000, MEMORY_TYPE_RECLAIMABLE, 0, NULL);
strncpy(cmdline, loader->cmdline, cmdline_size);
cmdline[cmdline_size] = 0;
params->hdr.cmd_line_ptr = (uint32_t)((ptr_t)cmdline);
// Determine the setup code size.
if (params->hdr.setup_sects)
setup_size = (params->hdr.setup_sects + 1) * 512;
else
setup_size = 5 * 512;
// Load size is total file size minus setup size.
load_size = loader->kernel->size - setup_size;
// Allocate memory for the kernel image.
virt = allocate_kernel(params, load_size, &phys);
if (!virt)
boot_error("Insufficient memory available for kernel image");
params->hdr.code32_start = phys + params->hdr.code32_start - LINUX_BZIMAGE_ADDR;
// Read in the kernel image.
ret = fs_read(loader->kernel, virt, load_size, setup_size);
if (ret != STATUS_SUCCESS)
boot_error("Error reading kernel image: %pS", ret);
// Load in the initrd(s).
if (loader->initrd_size) {
initrd_max = (params->hdr.version >= 0x0203)
? params->hdr.initrd_addr_max
: 0x37ffffff;
// It is recommended that the initrd be loaded as high as possible.
virt = memory_alloc(
round_up(loader->initrd_size, PAGE_SIZE), 0,
0x100000, initrd_max + 1, MEMORY_TYPE_MODULES, MEMORY_ALLOC_HIGH, &phys);
dprintf(
"linux: loading initrd to 0x%" PRIxPHYS " (size: 0x%zx, max: 0x%" PRIxPHYS ")\n",
phys, loader->initrd_size, initrd_max);
linux_initrd_load(loader, virt);
params->hdr.ramdisk_image = phys;
params->hdr.ramdisk_size = loader->initrd_size;
}
// Set the video mode.
linux_video_set(loader);
// Perform pre-boot tasks.
loader_preboot();
// Get the final memory map and print it out for informational purposes.
// Note that the memory_finalize() is necessary on EFI in order to free up
// any internal allocations in the EFI memory map so that they will be free
// to the kernel.
dprintf("linux: final physical memory map:\n");
memory_finalize(&memory_map);
memory_map_dump(&memory_map);
// Get platform code to do any setup it needs and enter the kernel.
// For BIOS, this will obtain information usually obtained by the real-mode
// bootstrap when using the 16-bit boot protocol, then jump to the 32-bit
// entry point. For EFI, this will enter the kernel using the handover
// protocol.
linux_platform_load(loader, params);
}
