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- /*
- * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
- *
- * 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; either version 2 of the
- * License, or any later version.
- *
- * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
- /**
- * @file
- *
- * Linux bzImage image format
- *
- */
-
- #include <stdint.h>
- #include <stdlib.h>
- #include <string.h>
- #include <errno.h>
- #include <assert.h>
- #include <realmode.h>
- #include <bzimage.h>
- #include <gpxe/uaccess.h>
- #include <gpxe/image.h>
- #include <gpxe/segment.h>
- #include <gpxe/init.h>
- #include <gpxe/initrd.h>
- #include <gpxe/cpio.h>
- #include <gpxe/features.h>
-
- FEATURE ( FEATURE_IMAGE, "bzImage", DHCP_EB_FEATURE_BZIMAGE, 1 );
-
- struct image_type bzimage_image_type __image_type ( PROBE_NORMAL );
-
- /**
- * bzImage load context
- */
- struct bzimage_load_context {
- /** Real-mode kernel portion load segment address */
- unsigned int rm_kernel_seg;
- /** Real-mode kernel portion load address */
- userptr_t rm_kernel;
- /** Real-mode kernel portion file size */
- size_t rm_filesz;
- /** Real-mode heap top (offset from rm_kernel) */
- size_t rm_heap;
- /** Command line (offset from rm_kernel) */
- size_t rm_cmdline;
- /** Real-mode kernel portion total memory size */
- size_t rm_memsz;
- /** Non-real-mode kernel portion load address */
- userptr_t pm_kernel;
- /** Non-real-mode kernel portion file and memory size */
- size_t pm_sz;
- };
-
- /**
- * bzImage execution context
- */
- struct bzimage_exec_context {
- /** Real-mode kernel portion load segment address */
- unsigned int rm_kernel_seg;
- /** Real-mode kernel portion load address */
- userptr_t rm_kernel;
- /** Real-mode heap top (offset from rm_kernel) */
- size_t rm_heap;
- /** Command line (offset from rm_kernel) */
- size_t rm_cmdline;
- /** Video mode */
- unsigned int vid_mode;
- /** Memory limit */
- uint64_t mem_limit;
- /** Initrd address */
- physaddr_t ramdisk_image;
- /** Initrd size */
- physaddr_t ramdisk_size;
- };
-
- /**
- * Parse kernel command line for bootloader parameters
- *
- * @v image bzImage file
- * @v exec_ctx Execution context
- * @v cmdline Kernel command line
- * @ret rc Return status code
- */
- static int bzimage_parse_cmdline ( struct image *image,
- struct bzimage_exec_context *exec_ctx,
- const char *cmdline ) {
- char *vga;
- char *mem;
-
- /* Look for "vga=" */
- if ( ( vga = strstr ( cmdline, "vga=" ) ) ) {
- vga += 4;
- if ( strcmp ( vga, "normal" ) == 0 ) {
- exec_ctx->vid_mode = BZI_VID_MODE_NORMAL;
- } else if ( strcmp ( vga, "ext" ) == 0 ) {
- exec_ctx->vid_mode = BZI_VID_MODE_EXT;
- } else if ( strcmp ( vga, "ask" ) == 0 ) {
- exec_ctx->vid_mode = BZI_VID_MODE_ASK;
- } else {
- exec_ctx->vid_mode = strtoul ( vga, &vga, 0 );
- if ( *vga && ( *vga != ' ' ) ) {
- DBGC ( image, "bzImage %p strange \"vga=\""
- "terminator '%c'\n", image, *vga );
- }
- }
- }
-
- /* Look for "mem=" */
- if ( ( mem = strstr ( cmdline, "mem=" ) ) ) {
- mem += 4;
- exec_ctx->mem_limit = strtoul ( mem, &mem, 0 );
- switch ( *mem ) {
- case 'G':
- case 'g':
- exec_ctx->mem_limit <<= 10;
- case 'M':
- case 'm':
- exec_ctx->mem_limit <<= 10;
- case 'K':
- case 'k':
- exec_ctx->mem_limit <<= 10;
- break;
- case '\0':
- case ' ':
- break;
- default:
- DBGC ( image, "bzImage %p strange \"mem=\" "
- "terminator '%c'\n", image, *mem );
- break;
- }
- exec_ctx->mem_limit -= 1;
- }
-
- return 0;
- }
-
- /**
- * Set command line
- *
- * @v image bzImage image
- * @v exec_ctx Execution context
- * @v cmdline Kernel command line
- * @ret rc Return status code
- */
- static int bzimage_set_cmdline ( struct image *image,
- struct bzimage_exec_context *exec_ctx,
- const char *cmdline ) {
- size_t cmdline_len;
-
- /* Copy command line down to real-mode portion */
- cmdline_len = ( strlen ( cmdline ) + 1 );
- if ( cmdline_len > BZI_CMDLINE_SIZE )
- cmdline_len = BZI_CMDLINE_SIZE;
- copy_to_user ( exec_ctx->rm_kernel, exec_ctx->rm_cmdline,
- cmdline, cmdline_len );
- DBGC ( image, "bzImage %p command line \"%s\"\n", image, cmdline );
-
- return 0;
- }
-
- /**
- * Load initrd
- *
- * @v image bzImage image
- * @v initrd initrd image
- * @v address Address at which to load, or UNULL
- * @ret len Length of loaded image, rounded up to 4 bytes
- */
- static size_t bzimage_load_initrd ( struct image *image,
- struct image *initrd,
- userptr_t address ) {
- char *filename = initrd->cmdline;
- struct cpio_header cpio;
- size_t offset = 0;
-
- /* Ignore images which aren't initrds */
- if ( initrd->type != &initrd_image_type )
- return 0;
-
- /* Create cpio header before non-prebuilt images */
- if ( filename && filename[0] ) {
- size_t name_len = ( strlen ( filename ) + 1 );
-
- DBGC ( image, "bzImage %p inserting initrd %p as %s\n",
- image, initrd, filename );
- memset ( &cpio, '0', sizeof ( cpio ) );
- memcpy ( cpio.c_magic, CPIO_MAGIC, sizeof ( cpio.c_magic ) );
- cpio_set_field ( cpio.c_mode, 0100644 );
- cpio_set_field ( cpio.c_nlink, 1 );
- cpio_set_field ( cpio.c_filesize, initrd->len );
- cpio_set_field ( cpio.c_namesize, name_len );
- if ( address ) {
- copy_to_user ( address, offset, &cpio,
- sizeof ( cpio ) );
- }
- offset += sizeof ( cpio );
- if ( address ) {
- copy_to_user ( address, offset, filename,
- name_len );
- }
- offset += name_len;
- offset = ( ( offset + 0x03 ) & ~0x03 );
- }
-
- /* Copy in initrd image body */
- if ( address ) {
- DBGC ( image, "bzImage %p has initrd %p at [%lx,%lx)\n",
- image, initrd, address, ( address + offset ) );
- memcpy_user ( address, offset, initrd->data, 0,
- initrd->len );
- }
- offset += initrd->len;
-
- offset = ( ( offset + 0x03 ) & ~0x03 );
- return offset;
- }
-
- /**
- * Load initrds, if any
- *
- * @v image bzImage image
- * @v exec_ctx Execution context
- * @ret rc Return status code
- */
- static int bzimage_load_initrds ( struct image *image,
- struct bzimage_exec_context *exec_ctx ) {
- struct image *initrd;
- size_t total_len = 0;
- physaddr_t address;
- int rc;
-
- /* Add up length of all initrd images */
- for_each_image ( initrd ) {
- total_len += bzimage_load_initrd ( image, initrd, UNULL );
- }
-
- /* Give up if no initrd images found */
- if ( ! total_len )
- return 0;
-
- /* Find a suitable start address. Try 1MB boundaries,
- * starting from the downloaded kernel image itself and
- * working downwards until we hit an available region.
- */
- for ( address = ( user_to_phys ( image->data, 0 ) & ~0xfffff ) ; ;
- address -= 0x100000 ) {
- /* Check that we're not going to overwrite the
- * kernel itself. This check isn't totally
- * accurate, but errs on the side of caution.
- */
- if ( address <= ( BZI_LOAD_HIGH_ADDR + image->len ) ) {
- DBGC ( image, "bzImage %p could not find a location "
- "for initrd\n", image );
- return -ENOBUFS;
- }
- /* Check that we are within the kernel's range */
- if ( ( address + total_len - 1 ) > exec_ctx->mem_limit )
- continue;
- /* Prepare and verify segment */
- if ( ( rc = prep_segment ( phys_to_user ( address ), 0,
- total_len ) ) != 0 )
- continue;
- /* Use this address */
- break;
- }
-
- /* Record initrd location */
- exec_ctx->ramdisk_image = address;
- exec_ctx->ramdisk_size = total_len;
-
- /* Construct initrd */
- DBGC ( image, "bzImage %p constructing initrd at [%lx,%lx)\n",
- image, address, ( address + total_len ) );
- for_each_image ( initrd ) {
- address += bzimage_load_initrd ( image, initrd,
- phys_to_user ( address ) );
- }
-
- return 0;
- }
-
- /**
- * Execute bzImage image
- *
- * @v image bzImage image
- * @ret rc Return status code
- */
- static int bzimage_exec ( struct image *image ) {
- struct bzimage_exec_context exec_ctx;
- struct bzimage_header bzhdr;
- const char *cmdline = ( image->cmdline ? image->cmdline : "" );
- int rc;
-
- /* Initialise context */
- memset ( &exec_ctx, 0, sizeof ( exec_ctx ) );
-
- /* Retrieve kernel header */
- exec_ctx.rm_kernel_seg = image->priv.ul;
- exec_ctx.rm_kernel = real_to_user ( exec_ctx.rm_kernel_seg, 0 );
- copy_from_user ( &bzhdr, exec_ctx.rm_kernel, BZI_HDR_OFFSET,
- sizeof ( bzhdr ) );
- exec_ctx.rm_cmdline = exec_ctx.rm_heap =
- ( bzhdr.heap_end_ptr + 0x200 );
- exec_ctx.vid_mode = bzhdr.vid_mode;
- if ( bzhdr.version >= 0x0203 ) {
- exec_ctx.mem_limit = bzhdr.initrd_addr_max;
- } else {
- exec_ctx.mem_limit = BZI_INITRD_MAX;
- }
-
- /* Parse command line for bootloader parameters */
- if ( ( rc = bzimage_parse_cmdline ( image, &exec_ctx, cmdline ) ) != 0)
- return rc;
-
- /* Store command line */
- if ( ( rc = bzimage_set_cmdline ( image, &exec_ctx, cmdline ) ) != 0 )
- return rc;
-
- /* Load any initrds */
- if ( ( rc = bzimage_load_initrds ( image, &exec_ctx ) ) != 0 )
- return rc;
-
- /* Update and store kernel header */
- bzhdr.vid_mode = exec_ctx.vid_mode;
- bzhdr.ramdisk_image = exec_ctx.ramdisk_image;
- bzhdr.ramdisk_size = exec_ctx.ramdisk_size;
- copy_to_user ( exec_ctx.rm_kernel, BZI_HDR_OFFSET, &bzhdr,
- sizeof ( bzhdr ) );
-
- /* Prepare for exiting */
- shutdown();
-
- DBGC ( image, "bzImage %p jumping to RM kernel at %04x:0000 "
- "(stack %04x:%04zx)\n", image,
- ( exec_ctx.rm_kernel_seg + 0x20 ),
- exec_ctx.rm_kernel_seg, exec_ctx.rm_heap );
-
- /* Jump to the kernel */
- __asm__ __volatile__ ( REAL_CODE ( "movw %w0, %%ds\n\t"
- "movw %w0, %%es\n\t"
- "movw %w0, %%fs\n\t"
- "movw %w0, %%gs\n\t"
- "movw %w0, %%ss\n\t"
- "movw %w1, %%sp\n\t"
- "pushw %w2\n\t"
- "pushw $0\n\t"
- "lret\n\t" )
- : : "r" ( exec_ctx.rm_kernel_seg ),
- "r" ( exec_ctx.rm_heap ),
- "r" ( exec_ctx.rm_kernel_seg + 0x20 ) );
-
- /* There is no way for the image to return, since we provide
- * no return address.
- */
- assert ( 0 );
-
- return -ECANCELED; /* -EIMPOSSIBLE */
- }
-
- /**
- * Load and parse bzImage header
- *
- * @v image bzImage file
- * @v load_ctx Load context
- * @v bzhdr Buffer for bzImage header
- * @ret rc Return status code
- */
- static int bzimage_load_header ( struct image *image,
- struct bzimage_load_context *load_ctx,
- struct bzimage_header *bzhdr ) {
-
- /* Sanity check */
- if ( image->len < ( BZI_HDR_OFFSET + sizeof ( *bzhdr ) ) ) {
- DBGC ( image, "bzImage %p too short for kernel header\n",
- image );
- return -ENOEXEC;
- }
-
- /* Read and verify header */
- copy_from_user ( bzhdr, image->data, BZI_HDR_OFFSET,
- sizeof ( *bzhdr ) );
- if ( bzhdr->header != BZI_SIGNATURE ) {
- DBGC ( image, "bzImage %p bad signature %08lx\n",
- image, bzhdr->header );
- return -ENOEXEC;
- }
-
- /* We don't support ancient kernels */
- if ( bzhdr->version < 0x0200 ) {
- DBGC ( image, "bzImage %p version %04x not supported\n",
- image, bzhdr->version );
- return -ENOTSUP;
- }
-
- /* Calculate load address and size of real-mode portion */
- load_ctx->rm_kernel_seg = 0x1000; /* place RM kernel at 1000:0000 */
- load_ctx->rm_kernel = real_to_user ( load_ctx->rm_kernel_seg, 0 );
- load_ctx->rm_filesz =
- ( ( bzhdr->setup_sects ? bzhdr->setup_sects : 4 ) + 1 ) << 9;
- load_ctx->rm_memsz = BZI_ASSUMED_RM_SIZE;
- if ( load_ctx->rm_filesz > image->len ) {
- DBGC ( image, "bzImage %p too short for %zd byte of setup\n",
- image, load_ctx->rm_filesz );
- return -ENOEXEC;
- }
-
- /* Calculate load address and size of non-real-mode portion */
- load_ctx->pm_kernel = ( ( bzhdr->loadflags & BZI_LOAD_HIGH ) ?
- phys_to_user ( BZI_LOAD_HIGH_ADDR ) :
- phys_to_user ( BZI_LOAD_LOW_ADDR ) );
- load_ctx->pm_sz = ( image->len - load_ctx->rm_filesz );
-
- DBGC ( image, "bzImage %p version %04x RM %#zx bytes PM %#zx bytes\n",
- image, bzhdr->version, load_ctx->rm_filesz, load_ctx->pm_sz );
- return 0;
- }
-
- /**
- * Load real-mode portion of bzImage
- *
- * @v image bzImage file
- * @v load_ctx Load context
- * @ret rc Return status code
- */
- static int bzimage_load_real ( struct image *image,
- struct bzimage_load_context *load_ctx ) {
- int rc;
-
- /* Allow space for the stack and heap */
- load_ctx->rm_memsz += BZI_STACK_SIZE;
- load_ctx->rm_heap = load_ctx->rm_memsz;
-
- /* Allow space for the command line */
- load_ctx->rm_cmdline = load_ctx->rm_memsz;
- load_ctx->rm_memsz += BZI_CMDLINE_SIZE;
-
- /* Prepare, verify, and load the real-mode segment */
- if ( ( rc = prep_segment ( load_ctx->rm_kernel, load_ctx->rm_filesz,
- load_ctx->rm_memsz ) ) != 0 ) {
- DBGC ( image, "bzImage %p could not prepare RM segment: %s\n",
- image, strerror ( rc ) );
- return rc;
- }
- memcpy_user ( load_ctx->rm_kernel, 0, image->data, 0,
- load_ctx->rm_filesz );
-
- return 0;
- }
-
- /**
- * Load non-real-mode portion of bzImage
- *
- * @v image bzImage file
- * @v load_ctx Load context
- * @ret rc Return status code
- */
- static int bzimage_load_non_real ( struct image *image,
- struct bzimage_load_context *load_ctx ) {
- int rc;
-
- /* Prepare, verify and load the non-real-mode segment */
- if ( ( rc = prep_segment ( load_ctx->pm_kernel, load_ctx->pm_sz,
- load_ctx->pm_sz ) ) != 0 ) {
- DBGC ( image, "bzImage %p could not prepare PM segment: %s\n",
- image, strerror ( rc ) );
- return rc;
- }
- memcpy_user ( load_ctx->pm_kernel, 0, image->data, load_ctx->rm_filesz,
- load_ctx->pm_sz );
-
- return 0;
- }
-
- /**
- * Update and store bzImage header
- *
- * @v image bzImage file
- * @v load_ctx Load context
- * @v bzhdr Original bzImage header
- * @ret rc Return status code
- */
- static int bzimage_write_header ( struct image *image __unused,
- struct bzimage_load_context *load_ctx,
- struct bzimage_header *bzhdr ) {
- struct bzimage_cmdline cmdline;
-
- /* Update the header and copy it into the loaded kernel */
- bzhdr->type_of_loader = BZI_LOADER_TYPE_GPXE;
- if ( bzhdr->version >= 0x0201 ) {
- bzhdr->heap_end_ptr = ( load_ctx->rm_heap - 0x200 );
- bzhdr->loadflags |= BZI_CAN_USE_HEAP;
- }
- if ( bzhdr->version >= 0x0202 ) {
- bzhdr->cmd_line_ptr = user_to_phys ( load_ctx->rm_kernel,
- load_ctx->rm_cmdline );
- } else {
- cmdline.magic = BZI_CMDLINE_MAGIC;
- cmdline.offset = load_ctx->rm_cmdline;
- copy_to_user ( load_ctx->rm_kernel, BZI_CMDLINE_OFFSET,
- &cmdline, sizeof ( cmdline ) );
- bzhdr->setup_move_size = load_ctx->rm_memsz;
- }
- copy_to_user ( load_ctx->rm_kernel, BZI_HDR_OFFSET,
- bzhdr, sizeof ( *bzhdr ) );
-
- return 0;
- }
-
- /**
- * Load bzImage image into memory
- *
- * @v image bzImage file
- * @ret rc Return status code
- */
- int bzimage_load ( struct image *image ) {
- struct bzimage_load_context load_ctx;
- struct bzimage_header bzhdr;
- int rc;
-
- /* Initialise context */
- memset ( &load_ctx, 0, sizeof ( load_ctx ) );
-
- /* Load and verify header */
- if ( ( rc = bzimage_load_header ( image, &load_ctx, &bzhdr ) ) != 0 )
- return rc;
-
- /* This is a bzImage image, valid or otherwise */
- if ( ! image->type )
- image->type = &bzimage_image_type;
-
- /* Load real-mode portion */
- if ( ( rc = bzimage_load_real ( image, &load_ctx ) ) != 0 )
- return rc;
-
- /* Load non-real-mode portion */
- if ( ( rc = bzimage_load_non_real ( image, &load_ctx ) ) != 0 )
- return rc;
-
- /* Update and write out header */
- if ( ( rc = bzimage_write_header ( image, &load_ctx, &bzhdr ) ) != 0 )
- return rc;
-
- /* Record real-mode segment in image private data field */
- image->priv.ul = load_ctx.rm_kernel_seg;
-
- return 0;
- }
-
- /** Linux bzImage image type */
- struct image_type bzimage_image_type __image_type ( PROBE_NORMAL ) = {
- .name = "bzImage",
- .load = bzimage_load,
- .exec = bzimage_exec,
- };
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