mirror of https://github.com/ipxe/ipxe.git
462 lines
12 KiB
C
462 lines
12 KiB
C
#include <errno.h>
|
|
#include <assert.h>
|
|
#include <realmode.h>
|
|
#include <gateA20.h>
|
|
#include <memsizes.h>
|
|
#include <basemem_packet.h>
|
|
#include <gpxe/uaccess.h>
|
|
#include <gpxe/segment.h>
|
|
#include <gpxe/shutdown.h>
|
|
#include <gpxe/netdevice.h>
|
|
#include <gpxe/dhcp.h>
|
|
#include <gpxe/image.h>
|
|
|
|
/** @file
|
|
*
|
|
* NBI image format.
|
|
*
|
|
* The Net Boot Image format is defined by the "Draft Net Boot Image
|
|
* Proposal 0.3" by Jamie Honan, Gero Kuhlmann and Ken Yap. It is now
|
|
* considered to be a legacy format, but it still included because a
|
|
* large amount of software (e.g. nymph, LTSP) makes use of NBI files.
|
|
*
|
|
* Etherboot does not implement the INT 78 callback interface
|
|
* described by the NBI specification. For a callback interface on
|
|
* x86 architecture, use PXE.
|
|
*
|
|
*/
|
|
|
|
struct image_type nbi_image_type __image_type ( PROBE_NORMAL );
|
|
|
|
/**
|
|
* An NBI image header
|
|
*
|
|
* Note that the length field uses a peculiar encoding; use the
|
|
* NBI_LENGTH() macro to decode the actual header length.
|
|
*
|
|
*/
|
|
struct imgheader {
|
|
unsigned long magic; /**< Magic number (NBI_MAGIC) */
|
|
union {
|
|
unsigned char length; /**< Nibble-coded header length */
|
|
unsigned long flags; /**< Image flags */
|
|
};
|
|
segoff_t location; /**< 16-bit seg:off header location */
|
|
union {
|
|
segoff_t segoff; /**< 16-bit seg:off entry point */
|
|
unsigned long linear; /**< 32-bit entry point */
|
|
} execaddr;
|
|
} __attribute__ (( packed ));
|
|
|
|
/** NBI magic number */
|
|
#define NBI_MAGIC 0x1B031336UL
|
|
|
|
/* Interpretation of the "length" fields */
|
|
#define NBI_NONVENDOR_LENGTH(len) ( ( (len) & 0x0f ) << 2 )
|
|
#define NBI_VENDOR_LENGTH(len) ( ( (len) & 0xf0 ) >> 2 )
|
|
#define NBI_LENGTH(len) ( NBI_NONVENDOR_LENGTH(len) + NBI_VENDOR_LENGTH(len) )
|
|
|
|
/* Interpretation of the "flags" fields */
|
|
#define NBI_PROGRAM_RETURNS(flags) ( (flags) & ( 1 << 8 ) )
|
|
#define NBI_LINEAR_EXEC_ADDR(flags) ( (flags) & ( 1 << 31 ) )
|
|
|
|
/** NBI header length */
|
|
#define NBI_HEADER_LENGTH 512
|
|
|
|
/**
|
|
* An NBI segment header
|
|
*
|
|
* Note that the length field uses a peculiar encoding; use the
|
|
* NBI_LENGTH() macro to decode the actual header length.
|
|
*
|
|
*/
|
|
struct segheader {
|
|
unsigned char length; /**< Nibble-coded header length */
|
|
unsigned char vendortag; /**< Vendor-defined private tag */
|
|
unsigned char reserved;
|
|
unsigned char flags; /**< Segment flags */
|
|
unsigned long loadaddr; /**< Load address */
|
|
unsigned long imglength; /**< Segment length in NBI file */
|
|
unsigned long memlength; /**< Segment length in memory */
|
|
};
|
|
|
|
/* Interpretation of the "flags" fields */
|
|
#define NBI_LOADADDR_FLAGS(flags) ( (flags) & 0x03 )
|
|
#define NBI_LOADADDR_ABS 0x00
|
|
#define NBI_LOADADDR_AFTER 0x01
|
|
#define NBI_LOADADDR_END 0x02
|
|
#define NBI_LOADADDR_BEFORE 0x03
|
|
#define NBI_LAST_SEGHEADER(flags) ( (flags) & ( 1 << 2 ) )
|
|
|
|
/* Define a type for passing info to a loaded program */
|
|
struct ebinfo {
|
|
uint8_t major, minor; /* Version */
|
|
uint16_t flags; /* Bit flags */
|
|
};
|
|
|
|
/** Info passed to NBI image */
|
|
static struct ebinfo loaderinfo = {
|
|
VERSION_MAJOR, VERSION_MINOR,
|
|
0
|
|
};
|
|
|
|
/**
|
|
* Prepare a segment for an NBI image
|
|
*
|
|
* @v image NBI image
|
|
* @v offset Offset within NBI image
|
|
* @v filesz Length of initialised-data portion of the segment
|
|
* @v memsz Total length of the segment
|
|
* @v src Source for initialised data
|
|
* @ret rc Return status code
|
|
*/
|
|
static int nbi_prepare_segment ( struct image *image, size_t offset __unused,
|
|
userptr_t dest, size_t filesz, size_t memsz ){
|
|
int rc;
|
|
|
|
if ( ( rc = prep_segment ( dest, filesz, memsz ) ) != 0 ) {
|
|
DBGC ( image, "NBI %p could not prepare segment: %s\n",
|
|
image, strerror ( rc ) );
|
|
return rc;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Load a segment for an NBI image
|
|
*
|
|
* @v image NBI image
|
|
* @v offset Offset within NBI image
|
|
* @v filesz Length of initialised-data portion of the segment
|
|
* @v memsz Total length of the segment
|
|
* @v src Source for initialised data
|
|
* @ret rc Return status code
|
|
*/
|
|
static int nbi_load_segment ( struct image *image, size_t offset,
|
|
userptr_t dest, size_t filesz,
|
|
size_t memsz __unused ) {
|
|
memcpy_user ( dest, 0, image->data, offset, filesz );
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Process segments of an NBI image
|
|
*
|
|
* @v image NBI image
|
|
* @v imgheader Image header information
|
|
* @v process Function to call for each segment
|
|
* @ret rc Return status code
|
|
*/
|
|
static int nbi_process_segments ( struct image *image,
|
|
struct imgheader *imgheader,
|
|
int ( * process ) ( struct image *image,
|
|
size_t offset,
|
|
userptr_t dest,
|
|
size_t filesz,
|
|
size_t memsz ) ) {
|
|
struct segheader sh;
|
|
size_t offset = 0;
|
|
size_t sh_off;
|
|
userptr_t dest;
|
|
size_t filesz;
|
|
size_t memsz;
|
|
int rc;
|
|
|
|
/* Copy image header to target location */
|
|
dest = real_to_user ( imgheader->location.segment,
|
|
imgheader->location.offset );
|
|
filesz = memsz = NBI_HEADER_LENGTH;
|
|
if ( ( rc = process ( image, offset, dest, filesz, memsz ) ) != 0 )
|
|
return rc;
|
|
offset += filesz;
|
|
|
|
/* Process segments in turn */
|
|
sh_off = NBI_LENGTH ( imgheader->length );
|
|
do {
|
|
/* Read segment header */
|
|
copy_from_user ( &sh, image->data, sh_off, sizeof ( sh ) );
|
|
if ( sh.length == 0 ) {
|
|
/* Avoid infinite loop? */
|
|
DBGC ( image, "NBI %p invalid segheader length 0\n",
|
|
image );
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* Calculate segment load address */
|
|
switch ( NBI_LOADADDR_FLAGS ( sh.flags ) ) {
|
|
case NBI_LOADADDR_ABS:
|
|
dest = phys_to_user ( sh.loadaddr );
|
|
break;
|
|
case NBI_LOADADDR_AFTER:
|
|
dest = userptr_add ( dest, memsz + sh.loadaddr );
|
|
break;
|
|
case NBI_LOADADDR_BEFORE:
|
|
dest = userptr_add ( dest, -sh.loadaddr );
|
|
break;
|
|
case NBI_LOADADDR_END:
|
|
/* Not correct according to the spec, but
|
|
* maintains backwards compatibility with
|
|
* previous versions of Etherboot.
|
|
*/
|
|
dest = phys_to_user ( ( extmemsize() + 1024 ) * 1024
|
|
- sh.loadaddr );
|
|
break;
|
|
default:
|
|
/* Cannot be reached */
|
|
assert ( 0 );
|
|
}
|
|
|
|
/* Process this segment */
|
|
filesz = sh.imglength;
|
|
memsz = sh.memlength;
|
|
if ( ( offset + filesz ) > image->len ) {
|
|
DBGC ( image, "NBI %p segment outside file\n", image );
|
|
return -ENOEXEC;
|
|
}
|
|
if ( ( rc = process ( image, offset, dest,
|
|
filesz, memsz ) ) != 0 ) {
|
|
return rc;
|
|
}
|
|
offset += filesz;
|
|
|
|
/* Next segheader */
|
|
sh_off += NBI_LENGTH ( sh.length );
|
|
if ( sh_off >= NBI_HEADER_LENGTH ) {
|
|
DBGC ( image, "NBI %p header overflow\n", image );
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
} while ( ! NBI_LAST_SEGHEADER ( sh.flags ) );
|
|
|
|
if ( offset != image->len ) {
|
|
DBGC ( image, "NBI %p length wrong (file %d, metadata %d)\n",
|
|
image, image->len, offset );
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Load an NBI image into memory
|
|
*
|
|
* @v image NBI image
|
|
* @ret rc Return status code
|
|
*/
|
|
int nbi_load ( struct image *image ) {
|
|
struct imgheader imgheader;
|
|
int rc;
|
|
|
|
/* If we don't have enough data give up */
|
|
if ( image->len < NBI_HEADER_LENGTH ) {
|
|
DBGC ( image, "NBI %p too short for an NBI image\n", image );
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* Check image header */
|
|
copy_from_user ( &imgheader, image->data, 0, sizeof ( imgheader ) );
|
|
if ( imgheader.magic != NBI_MAGIC ) {
|
|
DBGC ( image, "NBI %p has no NBI signature\n", image );
|
|
return -ENOEXEC;
|
|
}
|
|
|
|
/* This is an NBI image, valid or otherwise */
|
|
if ( ! image->type )
|
|
image->type = &nbi_image_type;
|
|
|
|
DBGC ( image, "NBI %p placing header at %hx:%hx\n", image,
|
|
imgheader.location.segment, imgheader.location.offset );
|
|
|
|
/* NBI files can have overlaps between segments; the bss of
|
|
* one segment may overlap the initialised data of another. I
|
|
* assume this is a design flaw, but there are images out
|
|
* there that we need to work with. We therefore do two
|
|
* passes: first to initialise the segments, then to copy the
|
|
* data. This avoids zeroing out already-copied data.
|
|
*/
|
|
if ( ( rc = nbi_process_segments ( image, &imgheader,
|
|
nbi_prepare_segment ) ) != 0 )
|
|
return rc;
|
|
if ( ( rc = nbi_process_segments ( image, &imgheader,
|
|
nbi_load_segment ) ) != 0 )
|
|
return rc;
|
|
|
|
/* Record header address in image private data field */
|
|
image->priv.user = real_to_user ( imgheader.location.segment,
|
|
imgheader.location.offset );
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Boot a 16-bit NBI image
|
|
*
|
|
* @v imgheader Image header information
|
|
* @ret rc Return status code, if image returns
|
|
*/
|
|
static int nbi_boot16 ( struct image *image, struct imgheader *imgheader ) {
|
|
int discard_D, discard_S, discard_b;
|
|
int rc;
|
|
|
|
DBGC ( image, "NBI %p executing 16-bit image at %04x:%04x\n", image,
|
|
imgheader->execaddr.segoff.segment,
|
|
imgheader->execaddr.segoff.offset );
|
|
|
|
gateA20_unset();
|
|
|
|
__asm__ __volatile__ (
|
|
REAL_CODE ( "pushw %%ds\n\t" /* far pointer to bootp data */
|
|
"pushw %%bx\n\t"
|
|
"pushl %%esi\n\t" /* location */
|
|
"pushw %%cs\n\t" /* lcall execaddr */
|
|
"call 1f\n\t"
|
|
"jmp 2f\n\t"
|
|
"\n1:\n\t"
|
|
"pushl %%edi\n\t"
|
|
"lret\n\t"
|
|
"\n2:\n\t"
|
|
"addw $8,%%sp\n\t" /* clean up stack */ )
|
|
: "=a" ( rc ), "=D" ( discard_D ), "=S" ( discard_S ),
|
|
"=b" ( discard_b )
|
|
: "D" ( imgheader->execaddr.segoff ),
|
|
"S" ( imgheader->location ),
|
|
"b" ( __from_data16 ( basemem_packet ) )
|
|
: "ecx", "edx", "ebp" );
|
|
|
|
gateA20_set();
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* Boot a 32-bit NBI image
|
|
*
|
|
* @v imgheader Image header information
|
|
* @ret rc Return status code, if image returns
|
|
*/
|
|
static int nbi_boot32 ( struct image *image, struct imgheader *imgheader ) {
|
|
int discard_D, discard_S, discard_b;
|
|
int rc;
|
|
|
|
DBGC ( image, "NBI %p executing 32-bit image at %lx\n",
|
|
image, imgheader->execaddr.linear );
|
|
|
|
/* no gateA20_unset for PM call */
|
|
|
|
/* Jump to OS with flat physical addressing */
|
|
__asm__ __volatile__ (
|
|
PHYS_CODE ( "pushl %%ebx\n\t" /* bootp data */
|
|
"pushl %%esi\n\t" /* imgheader */
|
|
"pushl %%eax\n\t" /* loaderinfo */
|
|
"call *%%edi\n\t"
|
|
"addl $12, %%esp\n\t" /* clean up stack */ )
|
|
: "=a" ( rc ), "=D" ( discard_D ), "=S" ( discard_S ),
|
|
"=b" ( discard_b )
|
|
: "D" ( imgheader->execaddr.linear ),
|
|
"S" ( ( imgheader->location.segment << 4 ) +
|
|
imgheader->location.offset ),
|
|
"b" ( virt_to_phys ( basemem_packet ) ),
|
|
"a" ( virt_to_phys ( &loaderinfo ) )
|
|
: "ecx", "edx", "ebp", "memory" );
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* Guess boot network device
|
|
*
|
|
* @ret netdev Boot network device
|
|
*/
|
|
static struct net_device * guess_boot_netdev ( void ) {
|
|
struct net_device *boot_netdev;
|
|
|
|
/* Just use the first network device */
|
|
for_each_netdev ( boot_netdev ) {
|
|
return boot_netdev;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/**
|
|
* Prepare DHCP parameter block for NBI image
|
|
*
|
|
* @v image NBI image
|
|
* @ret rc Return status code
|
|
*/
|
|
static int nbi_prepare_dhcp ( struct image *image ) {
|
|
struct dhcp_packet dhcppkt;
|
|
struct net_device *boot_netdev;
|
|
int rc;
|
|
|
|
boot_netdev = guess_boot_netdev();
|
|
if ( ! boot_netdev ) {
|
|
DBGC ( image, "NBI %p could not identify a network device\n",
|
|
image );
|
|
return -ENODEV;
|
|
}
|
|
|
|
if ( ( rc = create_dhcp_packet ( boot_netdev, DHCPACK, basemem_packet,
|
|
sizeof ( basemem_packet ),
|
|
&dhcppkt ) ) != 0 ) {
|
|
DBGC ( image, "NBI %p failed to build DHCP packet\n", image );
|
|
return rc;
|
|
}
|
|
if ( ( rc = copy_dhcp_packet_options ( &dhcppkt, NULL ) ) != 0 ) {
|
|
DBGC ( image, "NBI %p failed to copy DHCP options\n", image );
|
|
return rc;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Execute a loaded NBI image
|
|
*
|
|
* @v image NBI image
|
|
* @ret rc Return status code
|
|
*/
|
|
static int nbi_exec ( struct image *image ) {
|
|
struct imgheader imgheader;
|
|
int may_return;
|
|
int rc;
|
|
|
|
copy_from_user ( &imgheader, image->priv.user, 0,
|
|
sizeof ( imgheader ) );
|
|
|
|
/* Prepare DHCP option block */
|
|
if ( ( rc = nbi_prepare_dhcp ( image ) ) != 0 )
|
|
return rc;
|
|
|
|
/* Shut down now if NBI image will not return */
|
|
may_return = NBI_PROGRAM_RETURNS ( imgheader.flags );
|
|
if ( ! may_return )
|
|
shutdown();
|
|
|
|
/* Execute NBI image */
|
|
if ( NBI_LINEAR_EXEC_ADDR ( imgheader.flags ) ) {
|
|
rc = nbi_boot32 ( image, &imgheader );
|
|
} else {
|
|
rc = nbi_boot16 ( image, &imgheader );
|
|
}
|
|
|
|
if ( ! may_return ) {
|
|
/* Cannot continue after shutdown() called */
|
|
DBGC ( image, "NBI %p returned %d from non-returnable image\n",
|
|
image, rc );
|
|
while ( 1 ) {}
|
|
}
|
|
|
|
DBGC ( image, "NBI %p returned %d\n", image, rc );
|
|
|
|
return rc;
|
|
}
|
|
|
|
/** NBI image type */
|
|
struct image_type nbi_image_type __image_type ( PROBE_NORMAL ) = {
|
|
.name = "NBI",
|
|
.load = nbi_load,
|
|
.exec = nbi_exec,
|
|
};
|