/*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; If not, see <http://www.gnu.org/licenses/>.
*
* Some of the field descriptions were copied from "The Multiboot
* Specification", Copyright 1995, 96 Bryan Ford <baford@cs.utah.edu>,
* Erich Stefan Boleyn <erich@uruk.org> Copyright 1999, 2000, 2001, 2002
* Free Software Foundation, Inc.
*/
/******************************************************************************
*
* Loads simple binary images. It's like a .COM file in MS-DOS. No headers are
* present. The only requirement is that it must have a xen_bin_image table
* somewhere in the first 8192 bytes, starting on a 32-bit aligned address.
* Those familiar with the multiboot specification should recognize this, it's
* (almost) the same as the multiboot header.
* The layout of the xen_bin_image table is:
*
* Offset Type Name Note
* 0 uint32_t magic required
* 4 uint32_t flags required
* 8 uint32_t checksum required
* 12 uint32_t header_addr required
* 16 uint32_t load_addr required
* 20 uint32_t load_end_addr required
* 24 uint32_t bss_end_addr required
* 28 uint32_t entry_addr required
*
* - magic
* Magic number identifying the table. For images to be loaded by Xen 3, the
* magic value is 0x336ec578 ("xEn3" with the 0x80 bit of the "E" set).
* - flags
* bit 0: indicates whether the image needs to be loaded on a page boundary
* bit 1: reserved, must be 0 (the multiboot spec uses this bit to indicate
* that memory info should be passed to the image)
* bit 2: reserved, must be 0 (the multiboot spec uses this bit to indicate
* that the bootloader should pass video mode info to the image)
* bit 16: reserved, must be 1 (the multiboot spec uses this bit to indicate
* that the values in the fields header_addr - entry_addr are
* valid)
* All other bits should be set to 0.
* - checksum
* When added to "magic" and "flags", the resulting value should be 0.
* - header_addr
* Contains the virtual address corresponding to the beginning of the
* table - the memory location at which the magic value is supposed to be
* loaded. This field serves to synchronize the mapping between OS image
* offsets and virtual memory addresses.
* - load_addr
* Contains the virtual address of the beginning of the text segment. The
* offset in the OS image file at which to start loading is defined by the
* offset at which the table was found, minus (header addr - load addr).
* load addr must be less than or equal to header addr.
* - load_end_addr
* Contains the virtual address of the end of the data segment.
* (load_end_addr - load_addr) specifies how much data to load. This implies
* that the text and data segments must be consecutive in the OS image. If
* this field is zero, the domain builder assumes that the text and data
* segments occupy the whole OS image file.
* - bss_end_addr
* Contains the virtual address of the end of the bss segment. The domain
* builder initializes this area to zero, and reserves the memory it occupies
* to avoid placing boot modules and other data relevant to the loaded image
* in that area. If this field is zero, the domain builder assumes that no bss
* segment is present.
* - entry_addr
* The virtual address at which to start execution of the loaded image.
*
*/
#include <stdlib.h>
#include <inttypes.h>
#include "xg_private.h"
#include "xc_dom.h"
#define round_pgup(_p) (((_p)+(PAGE_SIZE_X86-1))&PAGE_MASK_X86)
#define round_pgdown(_p) ((_p)&PAGE_MASK_X86)
struct xen_bin_image_table
{
uint32_t magic;
uint32_t flags;
uint32_t checksum;
uint32_t header_addr;
uint32_t load_addr;
uint32_t load_end_addr;
uint32_t bss_end_addr;
uint32_t entry_addr;
};
#define XEN_MULTIBOOT_MAGIC3 0x336ec578
#define XEN_MULTIBOOT_FLAG_ALIGN4K 0x00000001
#define XEN_MULTIBOOT_FLAG_NEEDMEMINFO 0x00000002
#define XEN_MULTIBOOT_FLAG_NEEDVIDINFO 0x00000004
#define XEN_MULTIBOOT_FLAG_ADDRSVALID 0x00010000
#define XEN_MULTIBOOT_FLAG_PAE_SHIFT 14
#define XEN_MULTIBOOT_FLAG_PAE_MASK (3 << XEN_MULTIBOOT_FLAG_PAE_SHIFT)
/* Flags we test for */
#define FLAGS_MASK ((~ 0) & (~ XEN_MULTIBOOT_FLAG_ALIGN4K) & \
(~ XEN_MULTIBOOT_FLAG_PAE_MASK))
#define FLAGS_REQUIRED XEN_MULTIBOOT_FLAG_ADDRSVALID
/* --------------------------------------------------------------------- */
static struct xen_bin_image_table *find_table(struct xc_dom_image *dom)
{
struct xen_bin_image_table *table;
uint32_t *probe_ptr;
uint32_t *probe_end;
if ( dom->kernel_size < sizeof(*table) )
return NULL;
probe_ptr = dom->kernel_blob;
if ( dom->kernel_size > (8192 + sizeof(*table)) )
probe_end = dom->kernel_blob + 8192;
else
probe_end = dom->kernel_blob + dom->kernel_size - sizeof(*table);
for ( table = NULL; probe_ptr < probe_end; probe_ptr++ )
{
if ( *probe_ptr == XEN_MULTIBOOT_MAGIC3 )
{
table = (struct xen_bin_image_table *) probe_ptr;
/* Checksum correct? */
if ( (table->magic + table->flags + table->checksum) == 0 )
return table;
}
}
return NULL;
}
static int xc_dom_probe_bin_kernel(struct xc_dom_image *dom)
{
return find_table(dom) ? 0 : -EINVAL;
}
static int xc_dom_parse_bin_kernel(struct xc_dom_image *dom)
{
struct xen_bin_image_table *image_info;
char *image = dom->kernel_blob;
size_t image_size = dom->kernel_size;
uint32_t start_addr;
uint32_t load_end_addr;
uint32_t bss_end_addr;
uint32_t pae_flags;
image_info = find_table(dom);
if ( !image_info )
return -EINVAL;
DOMPRINTF("%s: multiboot header fields", __FUNCTION__);
DOMPRINTF(" flags: 0x%" PRIx32 "", image_info->flags);
DOMPRINTF(" header_addr: 0x%" PRIx32 "", image_info->header_addr);
DOMPRINTF(" load_addr: 0x%" PRIx32 "", image_info->load_addr);
DOMPRINTF(" load_end_addr: 0x%" PRIx32 "", image_info->load_end_addr);
DOMPRINTF(" bss_end_addr: 0x%" PRIx32 "", image_info->bss_end_addr);
DOMPRINTF(" entry_addr: 0x%" PRIx32 "", image_info->entry_addr);
/* Check the flags */
if ( (image_info->flags & FLAGS_MASK) != FLAGS_REQUIRED )
{
xc_dom_panic(dom->xch, XC_INVALID_KERNEL,
"%s: xen_bin_image_table flags required "
"0x%08" PRIx32 " found 0x%08" PRIx32 "",
__FUNCTION__, FLAGS_REQUIRED, image_info->flags & FLAGS_MASK);
return -EINVAL;
}
/* Sanity check on the addresses */
if ( (image_info->header_addr < image_info->load_addr) ||
((char *) image_info - image) <
(image_info->header_addr - image_info->load_addr) )
{
xc_dom_panic(dom->xch, XC_INVALID_KERNEL, "%s: Invalid header_addr.",
__FUNCTION__);
return -EINVAL;
}
start_addr = image_info->header_addr - ((char *)image_info - image);
load_end_addr = image_info->load_end_addr ?: start_addr + image_size;
bss_end_addr = image_info->bss_end_addr ?: load_end_addr;
DOMPRINTF("%s: calculated addresses", __FUNCTION__);
DOMPRINTF(" start_addr: 0x%" PRIx32 "", start_addr);
DOMPRINTF(" load_end_addr: 0x%" PRIx32 "", load_end_addr);
DOMPRINTF(" bss_end_addr: 0x%" PRIx32 "", bss_end_addr);
if ( (start_addr + image_size) < load_end_addr )
{
xc_dom_panic(dom->xch, XC_INVALID_KERNEL, "%s: Invalid load_end_addr.",
__FUNCTION__);
return -EINVAL;
}
if ( bss_end_addr < load_end_addr)
{
xc_dom_panic(dom->xch, XC_INVALID_KERNEL, "%s: Invalid bss_end_addr.",
__FUNCTION__);
return -EINVAL;
}
dom->kernel_seg.vstart = image_info->load_addr;
dom->kernel_seg.vend = bss_end_addr;
dom->parms.virt_base = start_addr;
dom->parms.virt_entry = image_info->entry_addr;
pae_flags = image_info->flags & XEN_MULTIBOOT_FLAG_PAE_MASK;
switch (pae_flags >> XEN_MULTIBOOT_FLAG_PAE_SHIFT) {
case 0:
dom->guest_type = "xen-3.0-x86_32";
break;
case 1:
dom->guest_type = "xen-3.0-x86_32p";
break;
case 2:
dom->guest_type = "xen-3.0-x86_64";
break;
case 3:
/* Kernel detects PAE at runtime. So try to figure whenever
* xen supports PAE and advertise a PAE-capable kernel in case
* it does. */
dom->guest_type = "xen-3.0-x86_32";
if ( strstr(dom->xen_caps, "xen-3.0-x86_32p") )
{
DOMPRINTF("%s: PAE fixup", __FUNCTION__);
dom->guest_type = "xen-3.0-x86_32p";
dom->parms.pae = XEN_PAE_EXTCR3;
}
break;
}
return 0;
}
static int xc_dom_load_bin_kernel(struct xc_dom_image *dom)
{
struct xen_bin_image_table *image_info;
char *image = dom->kernel_blob;
char *dest;
size_t image_size = dom->kernel_size;
size_t dest_size;
uint32_t start_addr;
uint32_t load_end_addr;
uint32_t bss_end_addr;
uint32_t skip, text_size, bss_size;
image_info = find_table(dom);
if ( !image_info )
return -EINVAL;
start_addr = image_info->header_addr - ((char *)image_info - image);
load_end_addr = image_info->load_end_addr ?: start_addr + image_size;
bss_end_addr = image_info->bss_end_addr ?: load_end_addr;
/* It's possible that we need to skip the first part of the image */
skip = image_info->load_addr - start_addr;
text_size = load_end_addr - image_info->load_addr;
bss_size = bss_end_addr - load_end_addr;
DOMPRINTF("%s: calculated sizes", __FUNCTION__);
DOMPRINTF(" skip: 0x%" PRIx32 "", skip);
DOMPRINTF(" text_size: 0x%" PRIx32 "", text_size);
DOMPRINTF(" bss_size: 0x%" PRIx32 "", bss_size);
dest = xc_dom_vaddr_to_ptr(dom, dom->kernel_seg.vstart, &dest_size);
if ( dest == NULL )
{
DOMPRINTF("%s: xc_dom_vaddr_to_ptr(dom, dom->kernel_seg.vstart)"
" => NULL", __FUNCTION__);
return -EINVAL;
}
if ( dest_size < text_size ||
dest_size - text_size < bss_size )
{
DOMPRINTF("%s: mapped region is too small for image", __FUNCTION__);
return -EINVAL;
}
if ( image_size < skip ||
image_size - skip < text_size )
{
DOMPRINTF("%s: image is too small for declared text size",
__FUNCTION__);
return -EINVAL;
}
memcpy(dest, image + skip, text_size);
memset(dest + text_size, 0, bss_size);
return 0;
}
/* ------------------------------------------------------------------------ */
static struct xc_dom_loader bin_loader = {
.name = "multiboot-binary",
.probe = xc_dom_probe_bin_kernel,
.parser = xc_dom_parse_bin_kernel,
.loader = xc_dom_load_bin_kernel,
};
static void __init register_loader(void)
{
xc_dom_register_loader(&bin_loader);
}
/*
* Local variables:
* mode: C
* c-file-style: "BSD"
* c-basic-offset: 4
* tab-width: 4
* indent-tabs-mode: nil
* End:
*/