diff options
Diffstat (limited to 'qemu/roms/ipxe/src/arch/i386/image/bzimage.c')
| -rw-r--r-- | qemu/roms/ipxe/src/arch/i386/image/bzimage.c | 665 |
1 files changed, 665 insertions, 0 deletions
diff --git a/qemu/roms/ipxe/src/arch/i386/image/bzimage.c b/qemu/roms/ipxe/src/arch/i386/image/bzimage.c new file mode 100644 index 000000000..4865c394c --- /dev/null +++ b/qemu/roms/ipxe/src/arch/i386/image/bzimage.c @@ -0,0 +1,665 @@ +/* + * 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., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +/** + * @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 <initrd.h> +#include <ipxe/uaccess.h> +#include <ipxe/image.h> +#include <ipxe/segment.h> +#include <ipxe/init.h> +#include <ipxe/cpio.h> +#include <ipxe/features.h> + +FEATURE ( FEATURE_IMAGE, "bzImage", DHCP_EB_FEATURE_BZIMAGE, 1 ); + +/** + * bzImage context + */ +struct bzimage_context { + /** Boot protocol version */ + unsigned int version; + /** 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; + /** Command line maximum length */ + size_t cmdline_size; + /** 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; + /** Video mode */ + unsigned int vid_mode; + /** Memory limit */ + uint64_t mem_limit; + /** Initrd address */ + physaddr_t ramdisk_image; + /** Initrd size */ + physaddr_t ramdisk_size; + + /** Command line magic block */ + struct bzimage_cmdline cmdline_magic; + /** bzImage header */ + struct bzimage_header bzhdr; +}; + +/** + * Parse bzImage header + * + * @v image bzImage file + * @v bzimg bzImage context + * @v src bzImage to parse + * @ret rc Return status code + */ +static int bzimage_parse_header ( struct image *image, + struct bzimage_context *bzimg, + userptr_t src ) { + unsigned int syssize; + int is_bzimage; + + /* Sanity check */ + if ( image->len < ( BZI_HDR_OFFSET + sizeof ( bzimg->bzhdr ) ) ) { + DBGC ( image, "bzImage %p too short for kernel header\n", + image ); + return -ENOEXEC; + } + + /* Read in header structures */ + memset ( bzimg, 0, sizeof ( *bzimg ) ); + copy_from_user ( &bzimg->cmdline_magic, src, BZI_CMDLINE_OFFSET, + sizeof ( bzimg->cmdline_magic ) ); + copy_from_user ( &bzimg->bzhdr, src, BZI_HDR_OFFSET, + sizeof ( bzimg->bzhdr ) ); + + /* Calculate size of real-mode portion */ + bzimg->rm_filesz = ( ( ( bzimg->bzhdr.setup_sects ? + bzimg->bzhdr.setup_sects : 4 ) + 1 ) << 9 ); + if ( bzimg->rm_filesz > image->len ) { + DBGC ( image, "bzImage %p too short for %zd byte of setup\n", + image, bzimg->rm_filesz ); + return -ENOEXEC; + } + bzimg->rm_memsz = BZI_ASSUMED_RM_SIZE; + + /* Calculate size of protected-mode portion */ + bzimg->pm_sz = ( image->len - bzimg->rm_filesz ); + syssize = ( ( bzimg->pm_sz + 15 ) / 16 ); + + /* Check for signatures and determine version */ + if ( bzimg->bzhdr.boot_flag != BZI_BOOT_FLAG ) { + DBGC ( image, "bzImage %p missing 55AA signature\n", image ); + return -ENOEXEC; + } + if ( bzimg->bzhdr.header == BZI_SIGNATURE ) { + /* 2.00+ */ + bzimg->version = bzimg->bzhdr.version; + } else { + /* Pre-2.00. Check that the syssize field is correct, + * as a guard against accepting arbitrary binary data, + * since the 55AA check is pretty lax. Note that the + * syssize field is unreliable for protocols between + * 2.00 and 2.03 inclusive, so we should not always + * check this field. + */ + bzimg->version = 0x0100; + if ( bzimg->bzhdr.syssize != syssize ) { + DBGC ( image, "bzImage %p bad syssize %x (expected " + "%x)\n", image, bzimg->bzhdr.syssize, syssize ); + return -ENOEXEC; + } + } + + /* Determine image type */ + is_bzimage = ( ( bzimg->version >= 0x0200 ) ? + ( bzimg->bzhdr.loadflags & BZI_LOAD_HIGH ) : 0 ); + + /* Calculate load address of real-mode portion */ + bzimg->rm_kernel_seg = ( is_bzimage ? 0x1000 : 0x9000 ); + bzimg->rm_kernel = real_to_user ( bzimg->rm_kernel_seg, 0 ); + + /* Allow space for the stack and heap */ + bzimg->rm_memsz += BZI_STACK_SIZE; + bzimg->rm_heap = bzimg->rm_memsz; + + /* Allow space for the command line */ + bzimg->rm_cmdline = bzimg->rm_memsz; + bzimg->rm_memsz += BZI_CMDLINE_SIZE; + + /* Calculate load address of protected-mode portion */ + bzimg->pm_kernel = phys_to_user ( is_bzimage ? BZI_LOAD_HIGH_ADDR + : BZI_LOAD_LOW_ADDR ); + + /* Extract video mode */ + bzimg->vid_mode = bzimg->bzhdr.vid_mode; + + /* Extract memory limit */ + bzimg->mem_limit = ( ( bzimg->version >= 0x0203 ) ? + bzimg->bzhdr.initrd_addr_max : BZI_INITRD_MAX ); + + /* Extract command line size */ + bzimg->cmdline_size = ( ( bzimg->version >= 0x0206 ) ? + bzimg->bzhdr.cmdline_size : BZI_CMDLINE_SIZE ); + + DBGC ( image, "bzImage %p version %04x RM %#lx+%#zx PM %#lx+%#zx " + "cmdlen %zd\n", image, bzimg->version, + user_to_phys ( bzimg->rm_kernel, 0 ), bzimg->rm_filesz, + user_to_phys ( bzimg->pm_kernel, 0 ), bzimg->pm_sz, + bzimg->cmdline_size ); + + return 0; +} + +/** + * Update bzImage header in loaded kernel + * + * @v image bzImage file + * @v bzimg bzImage context + * @v dst bzImage to update + */ +static void bzimage_update_header ( struct image *image, + struct bzimage_context *bzimg, + userptr_t dst ) { + + /* Set loader type */ + if ( bzimg->version >= 0x0200 ) + bzimg->bzhdr.type_of_loader = BZI_LOADER_TYPE_IPXE; + + /* Set heap end pointer */ + if ( bzimg->version >= 0x0201 ) { + bzimg->bzhdr.heap_end_ptr = ( bzimg->rm_heap - 0x200 ); + bzimg->bzhdr.loadflags |= BZI_CAN_USE_HEAP; + } + + /* Set command line */ + if ( bzimg->version >= 0x0202 ) { + bzimg->bzhdr.cmd_line_ptr = user_to_phys ( bzimg->rm_kernel, + bzimg->rm_cmdline ); + } else { + bzimg->cmdline_magic.magic = BZI_CMDLINE_MAGIC; + bzimg->cmdline_magic.offset = bzimg->rm_cmdline; + if ( bzimg->version >= 0x0200 ) + bzimg->bzhdr.setup_move_size = bzimg->rm_memsz; + } + + /* Set video mode */ + bzimg->bzhdr.vid_mode = bzimg->vid_mode; + + /* Set initrd address */ + if ( bzimg->version >= 0x0200 ) { + bzimg->bzhdr.ramdisk_image = bzimg->ramdisk_image; + bzimg->bzhdr.ramdisk_size = bzimg->ramdisk_size; + } + + /* Write out header structures */ + copy_to_user ( dst, BZI_CMDLINE_OFFSET, &bzimg->cmdline_magic, + sizeof ( bzimg->cmdline_magic ) ); + copy_to_user ( dst, BZI_HDR_OFFSET, &bzimg->bzhdr, + sizeof ( bzimg->bzhdr ) ); + + DBGC ( image, "bzImage %p vidmode %d\n", image, bzimg->vid_mode ); +} + +/** + * Parse kernel command line for bootloader parameters + * + * @v image bzImage file + * @v bzimg bzImage context + * @v cmdline Kernel command line + * @ret rc Return status code + */ +static int bzimage_parse_cmdline ( struct image *image, + struct bzimage_context *bzimg, + const char *cmdline ) { + char *vga; + char *mem; + + /* Look for "vga=" */ + if ( ( vga = strstr ( cmdline, "vga=" ) ) ) { + vga += 4; + if ( strcmp ( vga, "normal" ) == 0 ) { + bzimg->vid_mode = BZI_VID_MODE_NORMAL; + } else if ( strcmp ( vga, "ext" ) == 0 ) { + bzimg->vid_mode = BZI_VID_MODE_EXT; + } else if ( strcmp ( vga, "ask" ) == 0 ) { + bzimg->vid_mode = BZI_VID_MODE_ASK; + } else { + bzimg->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; + bzimg->mem_limit = strtoul ( mem, &mem, 0 ); + switch ( *mem ) { + case 'G': + case 'g': + bzimg->mem_limit <<= 10; + case 'M': + case 'm': + bzimg->mem_limit <<= 10; + case 'K': + case 'k': + bzimg->mem_limit <<= 10; + break; + case '\0': + case ' ': + break; + default: + DBGC ( image, "bzImage %p strange \"mem=\" " + "terminator '%c'\n", image, *mem ); + break; + } + bzimg->mem_limit -= 1; + } + + return 0; +} + +/** + * Set command line + * + * @v image bzImage image + * @v bzimg bzImage context + * @v cmdline Kernel command line + */ +static void bzimage_set_cmdline ( struct image *image, + struct bzimage_context *bzimg, + const char *cmdline ) { + size_t cmdline_len; + + /* Copy command line down to real-mode portion */ + cmdline_len = ( strlen ( cmdline ) + 1 ); + if ( cmdline_len > bzimg->cmdline_size ) + cmdline_len = bzimg->cmdline_size; + copy_to_user ( bzimg->rm_kernel, bzimg->rm_cmdline, + cmdline, cmdline_len ); + DBGC ( image, "bzImage %p command line \"%s\"\n", image, cmdline ); +} + +/** + * Parse standalone image command line for cpio parameters + * + * @v image bzImage file + * @v cpio CPIO header + * @v cmdline Command line + */ +static void bzimage_parse_cpio_cmdline ( struct image *image, + struct cpio_header *cpio, + const char *cmdline ) { + char *arg; + char *end; + unsigned int mode; + + /* Look for "mode=" */ + if ( ( arg = strstr ( cmdline, "mode=" ) ) ) { + arg += 5; + mode = strtoul ( arg, &end, 8 /* Octal for file mode */ ); + if ( *end && ( *end != ' ' ) ) { + DBGC ( image, "bzImage %p strange \"mode=\"" + "terminator '%c'\n", image, *end ); + } + cpio_set_field ( cpio->c_mode, ( 0100000 | mode ) ); + } +} + +/** + * Align initrd length + * + * @v len Length + * @ret len Length rounded up to INITRD_ALIGN + */ +static inline size_t bzimage_align ( size_t len ) { + + return ( ( len + INITRD_ALIGN - 1 ) & ~( INITRD_ALIGN - 1 ) ); +} + +/** + * 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, excluding zero-padding + */ +static size_t bzimage_load_initrd ( struct image *image, + struct image *initrd, + userptr_t address ) { + char *filename = initrd->cmdline; + char *cmdline; + struct cpio_header cpio; + size_t offset; + size_t name_len; + size_t pad_len; + + /* Do not include kernel image itself as an initrd */ + if ( initrd == image ) + return 0; + + /* Create cpio header for non-prebuilt images */ + if ( filename && filename[0] ) { + cmdline = strchr ( filename, ' ' ); + name_len = ( ( cmdline ? ( ( size_t ) ( cmdline - filename ) ) + : strlen ( filename ) ) + 1 /* NUL */ ); + 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 ( cmdline ) { + bzimage_parse_cpio_cmdline ( image, &cpio, + ( cmdline + 1 /* ' ' */ )); + } + offset = ( ( sizeof ( cpio ) + name_len + 0x03 ) & ~0x03 ); + } else { + offset = 0; + name_len = 0; + } + + /* Copy in initrd image body (and cpio header if applicable) */ + if ( address ) { + memmove_user ( address, offset, initrd->data, 0, initrd->len ); + if ( offset ) { + memset_user ( address, 0, 0, offset ); + copy_to_user ( address, 0, &cpio, sizeof ( cpio ) ); + copy_to_user ( address, sizeof ( cpio ), filename, + ( name_len - 1 /* NUL (or space) */ ) ); + } + DBGC ( image, "bzImage %p initrd %p [%#08lx,%#08lx,%#08lx)" + "%s%s\n", image, initrd, user_to_phys ( address, 0 ), + user_to_phys ( address, offset ), + user_to_phys ( address, ( offset + initrd->len ) ), + ( filename ? " " : "" ), ( filename ? filename : "" ) ); + DBGC2_MD5A ( image, user_to_phys ( address, offset ), + user_to_virt ( address, offset ), initrd->len ); + } + offset += initrd->len; + + /* Zero-pad to next INITRD_ALIGN boundary */ + pad_len = ( ( -offset ) & ( INITRD_ALIGN - 1 ) ); + if ( address ) + memset_user ( address, offset, 0, pad_len ); + + return offset; +} + +/** + * Check that initrds can be loaded + * + * @v image bzImage image + * @v bzimg bzImage context + * @ret rc Return status code + */ +static int bzimage_check_initrds ( struct image *image, + struct bzimage_context *bzimg ) { + struct image *initrd; + userptr_t bottom; + size_t len = 0; + int rc; + + /* Calculate total loaded length of initrds */ + for_each_image ( initrd ) { + + /* Skip kernel */ + if ( initrd == image ) + continue; + + /* Calculate length */ + len += bzimage_load_initrd ( image, initrd, UNULL ); + len = bzimage_align ( len ); + + DBGC ( image, "bzImage %p initrd %p from [%#08lx,%#08lx)%s%s\n", + image, initrd, user_to_phys ( initrd->data, 0 ), + user_to_phys ( initrd->data, initrd->len ), + ( initrd->cmdline ? " " : "" ), + ( initrd->cmdline ? initrd->cmdline : "" ) ); + DBGC2_MD5A ( image, user_to_phys ( initrd->data, 0 ), + user_to_virt ( initrd->data, 0 ), initrd->len ); + } + + /* Calculate lowest usable address */ + bottom = userptr_add ( bzimg->pm_kernel, bzimg->pm_sz ); + + /* Check that total length fits within space available for + * reshuffling. This is a conservative check, since CPIO + * headers are not present during reshuffling, but this + * doesn't hurt and keeps the code simple. + */ + if ( ( rc = initrd_reshuffle_check ( len, bottom ) ) != 0 ) { + DBGC ( image, "bzImage %p failed reshuffle check: %s\n", + image, strerror ( rc ) ); + return rc; + } + + /* Check that total length fits within kernel's memory limit */ + if ( user_to_phys ( bottom, len ) > bzimg->mem_limit ) { + DBGC ( image, "bzImage %p not enough space for initrds\n", + image ); + return -ENOBUFS; + } + + return 0; +} + +/** + * Load initrds, if any + * + * @v image bzImage image + * @v bzimg bzImage context + */ +static void bzimage_load_initrds ( struct image *image, + struct bzimage_context *bzimg ) { + struct image *initrd; + struct image *highest = NULL; + struct image *other; + userptr_t top; + userptr_t dest; + size_t offset; + size_t len; + + /* Reshuffle initrds into desired order */ + initrd_reshuffle ( userptr_add ( bzimg->pm_kernel, bzimg->pm_sz ) ); + + /* Find highest initrd */ + for_each_image ( initrd ) { + if ( ( highest == NULL ) || + ( userptr_sub ( initrd->data, highest->data ) > 0 ) ) { + highest = initrd; + } + } + + /* Do nothing if there are no initrds */ + if ( ! highest ) + return; + + /* Find highest usable address */ + top = userptr_add ( highest->data, bzimage_align ( highest->len ) ); + if ( user_to_phys ( top, 0 ) > bzimg->mem_limit ) + top = phys_to_user ( bzimg->mem_limit ); + DBGC ( image, "bzImage %p loading initrds from %#08lx downwards\n", + image, user_to_phys ( top, 0 ) ); + + /* Load initrds in order */ + for_each_image ( initrd ) { + + /* Calculate cumulative length of following + * initrds (including padding). + */ + offset = 0; + for_each_image ( other ) { + if ( other == initrd ) + offset = 0; + offset += bzimage_load_initrd ( image, other, UNULL ); + offset = bzimage_align ( offset ); + } + + /* Load initrd at this address */ + dest = userptr_add ( top, -offset ); + len = bzimage_load_initrd ( image, initrd, dest ); + + /* Record initrd location */ + if ( ! bzimg->ramdisk_image ) + bzimg->ramdisk_image = user_to_phys ( dest, 0 ); + bzimg->ramdisk_size = ( user_to_phys ( dest, len ) - + bzimg->ramdisk_image ); + } + DBGC ( image, "bzImage %p initrds at [%#08lx,%#08lx)\n", + image, bzimg->ramdisk_image, + ( bzimg->ramdisk_image + bzimg->ramdisk_size ) ); +} + +/** + * Execute bzImage image + * + * @v image bzImage image + * @ret rc Return status code + */ +static int bzimage_exec ( struct image *image ) { + struct bzimage_context bzimg; + const char *cmdline = ( image->cmdline ? image->cmdline : "" ); + int rc; + + /* Read and parse header from image */ + if ( ( rc = bzimage_parse_header ( image, &bzimg, + image->data ) ) != 0 ) + return rc; + + /* Prepare segments */ + if ( ( rc = prep_segment ( bzimg.rm_kernel, bzimg.rm_filesz, + bzimg.rm_memsz ) ) != 0 ) { + DBGC ( image, "bzImage %p could not prepare RM segment: %s\n", + image, strerror ( rc ) ); + return rc; + } + if ( ( rc = prep_segment ( bzimg.pm_kernel, bzimg.pm_sz, + bzimg.pm_sz ) ) != 0 ) { + DBGC ( image, "bzImage %p could not prepare PM segment: %s\n", + image, strerror ( rc ) ); + return rc; + } + + /* Parse command line for bootloader parameters */ + if ( ( rc = bzimage_parse_cmdline ( image, &bzimg, cmdline ) ) != 0) + return rc; + + /* Check that initrds can be loaded */ + if ( ( rc = bzimage_check_initrds ( image, &bzimg ) ) != 0 ) + return rc; + + /* Remove kernel from image list (without invalidating image pointer) */ + unregister_image ( image_get ( image ) ); + + /* Load segments */ + memcpy_user ( bzimg.rm_kernel, 0, image->data, + 0, bzimg.rm_filesz ); + memcpy_user ( bzimg.pm_kernel, 0, image->data, + bzimg.rm_filesz, bzimg.pm_sz ); + + /* Store command line */ + bzimage_set_cmdline ( image, &bzimg, cmdline ); + + /* Prepare for exiting. Must do this before loading initrds, + * since loading the initrds will corrupt the external heap. + */ + shutdown_boot(); + + /* Load any initrds */ + bzimage_load_initrds ( image, &bzimg ); + + /* Update kernel header */ + bzimage_update_header ( image, &bzimg, bzimg.rm_kernel ); + + DBGC ( image, "bzImage %p jumping to RM kernel at %04x:0000 " + "(stack %04x:%04zx)\n", image, ( bzimg.rm_kernel_seg + 0x20 ), + bzimg.rm_kernel_seg, bzimg.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" ( bzimg.rm_kernel_seg ), + "r" ( bzimg.rm_heap ), + "r" ( bzimg.rm_kernel_seg + 0x20 ) ); + + /* There is no way for the image to return, since we provide + * no return address. + */ + assert ( 0 ); + + return -ECANCELED; /* -EIMPOSSIBLE */ +} + +/** + * Probe bzImage image + * + * @v image bzImage file + * @ret rc Return status code + */ +int bzimage_probe ( struct image *image ) { + struct bzimage_context bzimg; + int rc; + + /* Read and parse header from image */ + if ( ( rc = bzimage_parse_header ( image, &bzimg, + image->data ) ) != 0 ) + return rc; + + return 0; +} + +/** Linux bzImage image type */ +struct image_type bzimage_image_type __image_type ( PROBE_NORMAL ) = { + .name = "bzImage", + .probe = bzimage_probe, + .exec = bzimage_exec, +}; |