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xen/tools/libxc/xc_load_bin.c
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cl349@firebug.cl.cam.ac.uk b94f8b3861 bitkeeper revision 1.1680 (42a4100bIstutWsVAoi7aPO8tLbFkA) 
xc_load_elf.c, xc_load_bin.c:
  Fix missing rename (xc_*_probe -> probe_*) from previous commit.
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
2005-06-06 08:57:47 +00:00

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/******************************************************************************
* xc_bin_load.c
*
* Based on xc_elf_load.c
*
* 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 u32 magic required
* 4 u32 flags required
* 8 u32 checksum required
* 12 u32 header_addr required
* 16 u32 load_addr required
* 20 u32 load_end_addr required
* 24 u32 bss_end_addr required
* 28 u32 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.
*
* 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.
*/
#include "xc_private.h"
#include <stdlib.h>
#define L1_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED)
#define L2_PROT (_PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY|_PAGE_USER)
#define round_pgup(_p) (((_p)+(PAGE_SIZE-1))&PAGE_MASK)
#define round_pgdown(_p) ((_p)&PAGE_MASK)
struct xen_bin_image_table
{
unsigned long magic;
unsigned long flags;
unsigned long checksum;
unsigned long header_addr;
unsigned long load_addr;
unsigned long load_end_addr;
unsigned long bss_end_addr;
unsigned long entry_addr;
};
#define XEN_REACTOS_MAGIC3 0x336ec578
#define XEN_REACTOS_FLAG_ALIGN4K 0x00000001
#define XEN_REACTOS_FLAG_NEEDMEMINFO 0x00000002
#define XEN_REACTOS_FLAG_NEEDVIDINFO 0x00000004
#define XEN_REACTOS_FLAG_ADDRSVALID 0x00010000
/* Flags we test for */
#define FLAGS_MASK ((~ 0) & (~ XEN_REACTOS_FLAG_ALIGN4K))
#define FLAGS_REQUIRED XEN_REACTOS_FLAG_ADDRSVALID
static struct xen_bin_image_table *
findtable(char *image, unsigned long image_size);
static int
parsebinimage(
char *image, unsigned long image_size, struct domain_setup_info *dsi);
static int
loadbinimage(
char *image, unsigned long image_size, int xch, u32 dom,
unsigned long *parray, struct domain_setup_info *dsi);
int probe_bin(char *image,
unsigned long image_size,
struct load_funcs *load_funcs)
{
if ( NULL == findtable(image, image_size) )
{
return -EINVAL;
}
load_funcs->parseimage = parsebinimage;
load_funcs->loadimage = loadbinimage;
return 0;
}
static struct xen_bin_image_table *
findtable(char *image, unsigned long image_size)
{
struct xen_bin_image_table *table;
unsigned long *probe_ptr;
unsigned probe_index;
unsigned probe_count;
/* Don't go outside the image */
if ( image_size < sizeof(struct xen_bin_image_table) )
{
return NULL;
}
probe_count = image_size;
/* Restrict to first 8k */
if ( 8192 < probe_count )
{
probe_count = 8192;
}
probe_count = (probe_count - sizeof(struct xen_bin_image_table)) /
sizeof(unsigned long);
/* Search for the magic header */
probe_ptr = (unsigned long *) image;
table = NULL;
for ( probe_index = 0; probe_index < probe_count; probe_index++ )
{
if ( XEN_REACTOS_MAGIC3 == *probe_ptr )
{
table = (struct xen_bin_image_table *) probe_ptr;
/* Checksum correct? */
if ( 0 == table->magic + table->flags + table->checksum )
{
return table;
}
}
probe_ptr++;
}
return NULL;
}
static int parsebinimage(char *image,
unsigned long image_size,
struct domain_setup_info *dsi)
{
struct xen_bin_image_table *image_info;
unsigned long start_addr;
unsigned long end_addr;
image_info = findtable(image, image_size);
if ( NULL == image_info )
{
ERROR("Image does not have a valid xen_bin_image_table table.");
return -EINVAL;
}
/* Check the flags */
if ( FLAGS_REQUIRED != (image_info->flags & FLAGS_MASK) )
{
ERROR("xen_bin_image_table flags required 0x%08x found 0x%08lx",
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) )
{
ERROR("Invalid header_addr.");
return -EINVAL;
}
start_addr = image_info->header_addr - ((char *) image_info - image);
if ( 0 != image_info->load_end_addr &&
( image_info->load_end_addr < image_info->load_end_addr ||
start_addr + image_size < image_info->load_end_addr ) )
{
ERROR("Invalid load_end_addr");
return -EINVAL;
}
end_addr = (0 == image_info->load_end_addr ? start_addr + image_size :
image_info->load_end_addr);
if ( 0 != image_info->bss_end_addr &&
image_info->bss_end_addr < end_addr )
{
ERROR("Invalid bss_end_addr");
return -EINVAL;
}
dsi->v_start = image_info->load_addr;
if ( 0 != image_info->bss_end_addr )
{
dsi->v_end = image_info->bss_end_addr;
}
else if ( 0 != image_info->load_end_addr )
{
dsi->v_end = image_info->load_end_addr;
}
else
{
dsi->v_end = image_info->load_addr + image_size -
(((char *) image_info - image) -
(image_info->header_addr - image_info->load_addr));
}
dsi->v_kernstart = dsi->v_start;
dsi->v_kernend = dsi->v_end;
dsi->v_kernentry = image_info->entry_addr;
return 0;
}
static int
loadbinimage(
char *image, unsigned long image_size, int xch, u32 dom,
unsigned long *parray, struct domain_setup_info *dsi)
{
unsigned long size;
char *va;
unsigned long done, chunksz;
struct xen_bin_image_table *image_info;
image_info = findtable(image, image_size);
if ( NULL == image_info )
{
ERROR("Image does not have a valid xen_bin_image_table table.");
return -EINVAL;
}
/* Determine image size */
if ( 0 == image_info->load_end_addr )
{
size = image_size - (((char *) image_info - image) -
(image_info->header_addr -
image_info->load_addr));
}
else
{
size = image_info->load_end_addr - image_info->load_addr;
}
/* It's possible that we need to skip the first part of the image */
image += ((char *)image_info - image) -
(image_info->header_addr - image_info->load_addr);
for ( done = 0; done < size; done += chunksz )
{
va = xc_map_foreign_range(
xch, dom, PAGE_SIZE, PROT_WRITE, parray[done>>PAGE_SHIFT]);
chunksz = size - done;
if ( chunksz > PAGE_SIZE )
chunksz = PAGE_SIZE;
memcpy(va, image + done, chunksz);
munmap(va, PAGE_SIZE);
}
if ( 0 != image_info->bss_end_addr &&
image_info->load_addr + size < image_info->bss_end_addr )
{
size = image_info->bss_end_addr - image_info->load_addr;
}
for ( ; done < size; done += chunksz )
{
va = xc_map_foreign_range(
xch, dom, PAGE_SIZE, PROT_WRITE, parray[done>>PAGE_SHIFT]);
chunksz = size - done;
if ( chunksz > (PAGE_SIZE - (done & (PAGE_SIZE-1))) )
chunksz = PAGE_SIZE - (done & (PAGE_SIZE-1));
memset(va + (done & (PAGE_SIZE-1)), 0, chunksz);
munmap(va, PAGE_SIZE);
}
return 0;
}
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