/**
* Deallocate space on the real-mode stack, optionally copying back
* data to a user buffer.
*
* @v data User buffer
* @v size Size of stack data
*/
void remove_user_from_rm_stack ( userptr_t data, size_t size ) {
if ( data ) {
userptr_t rm_stack = real_to_user ( rm_ss, rm_sp );
memcpy_user ( rm_stack, 0, data, 0, size );
}
rm_sp += size;
};
/**
* Allocate space on the real-mode stack and copy data there from a
* user buffer
*
* @v data User buffer
* @v size Size of stack data
* @ret sp New value of real-mode stack pointer
*/
uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size ) {
userptr_t rm_stack;
rm_sp -= size;
rm_stack = real_to_user ( rm_ss, rm_sp );
memcpy_user ( rm_stack, 0, data, 0, size );
return rm_sp;
};
/**
* Initialise initrd
*
* @ret rc Return status code
*/
static int initrd_init ( void ) {
struct image *image;
int rc;
/* Do nothing if no initrd was specified */
if ( ! initrd_phys ) {
DBGC ( colour, "RUNTIME found no initrd\n" );
return 0;
}
if ( ! initrd_len ) {
DBGC ( colour, "RUNTIME found empty initrd\n" );
return 0;
}
DBGC ( colour, "RUNTIME found initrd at [%x,%x)\n",
initrd_phys, ( initrd_phys + initrd_len ) );
/* Allocate image */
image = alloc_image();
if ( ! image ) {
DBGC ( colour, "RUNTIME could not allocate image for "
"initrd\n" );
rc = -ENOMEM;
goto err_alloc_image;
}
image_set_name ( image, "<INITRD>" );
/* Allocate and copy initrd content */
image->data = umalloc ( initrd_len );
if ( ! image->data ) {
DBGC ( colour, "RUNTIME could not allocate %zd bytes for "
"initrd\n", initrd_len );
rc = -ENOMEM;
goto err_umalloc;
}
image->len = initrd_len;
memcpy_user ( image->data, 0, phys_to_user ( initrd_phys ), 0,
initrd_len );
/* Mark initrd as consumed */
initrd_phys = 0;
/* Register image */
if ( ( rc = register_image ( image ) ) != 0 ) {
DBGC ( colour, "RUNTIME could not register initrd: %s\n",
strerror ( rc ) );
goto err_register_image;
}
/* Drop our reference to the image */
image_put ( image );
return 0;
err_register_image:
err_umalloc:
image_put ( image );
err_alloc_image:
return rc;
}
/**
* Reallocate external memory
*
* @v old_ptr Memory previously allocated by umalloc(), or UNULL
* @v new_size Requested size
* @ret new_ptr Allocated memory, or UNULL
*
* Calling realloc() with a new size of zero is a valid way to free a
* memory block.
*/
static userptr_t efi_urealloc ( userptr_t old_ptr, size_t new_size ) {
EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
EFI_PHYSICAL_ADDRESS phys_addr;
unsigned int new_pages, old_pages;
userptr_t new_ptr = UNOWHERE;
size_t old_size;
EFI_STATUS efirc;
int rc;
/* Allocate new memory if necessary. If allocation fails,
* return without touching the old block.
*/
if ( new_size ) {
new_pages = ( EFI_SIZE_TO_PAGES ( new_size ) + 1 );
if ( ( efirc = bs->AllocatePages ( AllocateAnyPages,
EfiBootServicesData,
new_pages,
&phys_addr ) ) != 0 ) {
rc = -EEFI ( efirc );
DBG ( "EFI could not allocate %d pages: %s\n",
new_pages, strerror ( rc ) );
return UNULL;
}
assert ( phys_addr != 0 );
new_ptr = phys_to_user ( phys_addr + EFI_PAGE_SIZE );
copy_to_user ( new_ptr, -EFI_PAGE_SIZE,
&new_size, sizeof ( new_size ) );
DBG ( "EFI allocated %d pages at %llx\n",
new_pages, phys_addr );
}
/* Copy across relevant part of the old data region (if any),
* then free it. Note that at this point either (a) new_ptr
* is valid, or (b) new_size is 0; either way, the memcpy() is
* valid.
*/
if ( old_ptr && ( old_ptr != UNOWHERE ) ) {
copy_from_user ( &old_size, old_ptr, -EFI_PAGE_SIZE,
sizeof ( old_size ) );
memcpy_user ( new_ptr, 0, old_ptr, 0,
( (old_size < new_size) ? old_size : new_size ));
old_pages = ( EFI_SIZE_TO_PAGES ( old_size ) + 1 );
phys_addr = user_to_phys ( old_ptr, -EFI_PAGE_SIZE );
if ( ( efirc = bs->FreePages ( phys_addr, old_pages ) ) != 0 ){
rc = -EEFI ( efirc );
DBG ( "EFI could not free %d pages at %llx: %s\n",
old_pages, phys_addr, strerror ( rc ) );
/* Not fatal; we have leaked memory but successfully
* allocated (if asked to do so).
*/
}
DBG ( "EFI freed %d pages at %llx\n", old_pages, phys_addr );
}
return new_ptr;
}
/**
* Execute PXE image
*
* @v image PXE image
* @ret rc Return status code
*/
static int pxe_exec ( struct image *image ) {
userptr_t buffer = real_to_user ( 0, 0x7c00 );
struct net_device *netdev;
int rc;
/* Verify and prepare segment */
if ( ( rc = prep_segment ( buffer, image->len, image->len ) ) != 0 ) {
DBGC ( image, "IMAGE %p could not prepare segment: %s\n",
image, strerror ( rc ) );
return rc;
}
/* Copy image to segment */
memcpy_user ( buffer, 0, image->data, 0, image->len );
/* Arbitrarily pick the most recently opened network device */
if ( ( netdev = last_opened_netdev() ) == NULL ) {
DBGC ( image, "IMAGE %p could not locate PXE net device\n",
image );
return -ENODEV;
}
netdev_get ( netdev );
/* Activate PXE */
pxe_activate ( netdev );
/* Construct fake DHCP packets */
pxe_fake_cached_info();
/* Set PXE command line */
pxe_cmdline = image->cmdline;
/* Reset console since PXE NBP will probably use it */
console_reset();
/* Disable IRQ, if applicable */
if ( netdev_irq_supported ( netdev ) && netdev->dev->desc.irq )
disable_irq ( netdev->dev->desc.irq );
/* Start PXE NBP */
rc = pxe_start_nbp();
/* Clear PXE command line */
pxe_cmdline = NULL;
/* Deactivate PXE */
pxe_deactivate();
/* Try to reopen network device. Ignore errors, since the NBP
* may have called PXENV_STOP_UNDI.
*/
netdev_open ( netdev );
netdev_put ( netdev );
return rc;
}
/**
* Load ELF segment into memory
*
* @v image ELF file
* @v phdr ELF program header
* @ret rc Return status code
*/
static int elf_load_segment ( struct image *image, Elf_Phdr *phdr ) {
physaddr_t dest;
userptr_t buffer;
int rc;
/* Do nothing for non-PT_LOAD segments */
if ( phdr->p_type != PT_LOAD )
return 0;
/* Check segment lies within image */
if ( ( phdr->p_offset + phdr->p_filesz ) > image->len ) {
DBG ( "ELF segment outside ELF file\n" );
return -ENOEXEC;
}
/* Find start address: use physical address for preference,
* fall back to virtual address if no physical address
* supplied.
*/
dest = phdr->p_paddr;
if ( ! dest )
dest = phdr->p_vaddr;
if ( ! dest ) {
DBG ( "ELF segment loads to physical address 0\n" );
return -ENOEXEC;
}
buffer = phys_to_user ( dest );
DBG ( "ELF loading segment [%x,%x) to [%x,%x,%x)\n",
phdr->p_offset, ( phdr->p_offset + phdr->p_filesz ),
phdr->p_paddr, ( phdr->p_paddr + phdr->p_filesz ),
( phdr->p_paddr + phdr->p_memsz ) );
/* Verify and prepare segment */
if ( ( rc = prep_segment ( buffer, phdr->p_filesz,
phdr->p_memsz ) ) != 0 ) {
DBG ( "ELF could not prepare segment: %s\n", strerror ( rc ) );
return rc;
}
/* Copy image to segment */
memcpy_user ( buffer, 0, image->data, phdr->p_offset, phdr->p_filesz );
return 0;
}
/**
* Load PXE image into memory
*
* @v image PXE file
* @ret rc Return status code
*/
int pxe_load ( struct image *image ) {
userptr_t buffer = real_to_user ( 0, 0x7c00 );
size_t filesz = image->len;
size_t memsz = image->len;
int rc;
/* Images too large to fit in base memory cannot be PXE
* images. We include this check to help prevent unrecognised
* images from being marked as PXE images, since PXE images
* have no signature we can check against.
*/
if ( filesz > ( 0xa0000 - 0x7c00 ) )
return -ENOEXEC;
/* Rejecting zero-length images is also useful, since these
* end up looking to the user like bugs in gPXE.
*/
if ( ! filesz )
return -ENOEXEC;
/* There are no signature checks for PXE; we will accept anything */
if ( ! image->type )
image->type = &pxe_image_type;
/* Verify and prepare segment */
if ( ( rc = prep_segment ( buffer, filesz, memsz ) ) != 0 ) {
DBGC ( image, "IMAGE %p could not prepare segment: %s\n",
image, strerror ( rc ) );
return rc;
}
/* Copy image to segment */
memcpy_user ( buffer, 0, image->data, 0, filesz );
return 0;
}
/**
* Load ELF segment into memory
*
* @v image ELF file
* @v phdr ELF program header
* @v ehdr ELF executable header
* @ret entry Entry point, if found
* @ret max Maximum used address
* @ret rc Return status code
*/
static int elf_load_segment ( struct image *image, Elf_Phdr *phdr,
Elf_Ehdr *ehdr, physaddr_t *entry,
physaddr_t *max ) {
physaddr_t dest;
physaddr_t end;
userptr_t buffer;
unsigned long e_offset;
int rc;
/* Do nothing for non-PT_LOAD segments */
if ( phdr->p_type != PT_LOAD )
return 0;
/* Check segment lies within image */
if ( ( phdr->p_offset + phdr->p_filesz ) > image->len ) {
DBGC ( image, "ELF %p segment outside image\n", image );
return -ENOEXEC;
}
/* Find start address: use physical address for preference,
* fall back to virtual address if no physical address
* supplied.
*/
dest = phdr->p_paddr;
if ( ! dest )
dest = phdr->p_vaddr;
if ( ! dest ) {
DBGC ( image, "ELF %p segment loads to physical address 0\n",
image );
return -ENOEXEC;
}
buffer = phys_to_user ( dest );
end = ( dest + phdr->p_memsz );
DBGC ( image, "ELF %p loading segment [%x,%x) to [%x,%x,%x)\n", image,
phdr->p_offset, ( phdr->p_offset + phdr->p_filesz ),
phdr->p_paddr, ( phdr->p_paddr + phdr->p_filesz ),
( phdr->p_paddr + phdr->p_memsz ) );
/* Verify and prepare segment */
if ( ( rc = prep_segment ( buffer, phdr->p_filesz,
phdr->p_memsz ) ) != 0 ) {
DBGC ( image, "ELF %p could not prepare segment: %s\n",
image, strerror ( rc ) );
return rc;
}
/* Update maximum used address, if applicable */
if ( end > *max )
*max = end;
/* Copy image to segment */
memcpy_user ( buffer, 0, image->data, phdr->p_offset, phdr->p_filesz );
/* Set execution address, if it lies within this segment */
if ( ( e_offset = ( ehdr->e_entry - dest ) ) < phdr->p_filesz ) {
*entry = ehdr->e_entry;
DBGC ( image, "ELF %p found physical entry point at %lx\n",
image, *entry );
} else if ( ( e_offset = ( ehdr->e_entry - phdr->p_vaddr ) )
< phdr->p_filesz ) {
if ( ! *entry ) {
*entry = ( dest + e_offset );
DBGC ( image, "ELF %p found virtual entry point at %lx"
" (virt %lx)\n", image, *entry,
( ( unsigned long ) ehdr->e_entry ) );
}
}
return 0;
}
/**
* Read and verify El Torito Boot Record Volume Descriptor
*
* @v image El Torito file
* @ret catalog_offset Offset of Boot Catalog
* @ret rc Return status code
*/
static int eltorito_read_voldesc ( struct image *image,
unsigned long *catalog_offset ) {
static const struct eltorito_vol_desc vol_desc_signature = {
.record_indicator = 0,
.iso9660_id = "CD001",
.version = 1,
.system_indicator = "EL TORITO SPECIFICATION",
};
struct eltorito_vol_desc vol_desc;
/* Sanity check */
if ( image->len < ( ELTORITO_VOL_DESC_OFFSET + ISO9660_BLKSIZE ) ) {
DBGC ( image, "ElTorito %p too short\n", image );
return -ENOEXEC;
}
/* Read and verify Boot Record Volume Descriptor */
copy_from_user ( &vol_desc, image->data, ELTORITO_VOL_DESC_OFFSET,
sizeof ( vol_desc ) );
if ( memcmp ( &vol_desc, &vol_desc_signature,
offsetof ( typeof ( vol_desc ), sector ) ) != 0 ) {
DBGC ( image, "ElTorito %p invalid Boot Record Volume "
"Descriptor\n", image );
return -ENOEXEC;
}
*catalog_offset = ( vol_desc.sector * ISO9660_BLKSIZE );
DBGC ( image, "ElTorito %p boot catalog at offset %#lx\n",
image, *catalog_offset );
return 0;
}
/**
* Read and verify El Torito Boot Catalog
*
* @v image El Torito file
* @v catalog_offset Offset of Boot Catalog
* @ret boot_entry El Torito boot entry
* @ret rc Return status code
*/
static int eltorito_read_catalog ( struct image *image,
unsigned long catalog_offset,
struct eltorito_boot_entry *boot_entry ) {
struct eltorito_validation_entry validation_entry;
/* Sanity check */
if ( image->len < ( catalog_offset + ISO9660_BLKSIZE ) ) {
DBGC ( image, "ElTorito %p bad boot catalog offset %#lx\n",
image, catalog_offset );
return -ENOEXEC;
}
/* Read and verify the Validation Entry of the Boot Catalog */
copy_from_user ( &validation_entry, image->data, catalog_offset,
sizeof ( validation_entry ) );
if ( word_checksum ( &validation_entry,
sizeof ( validation_entry ) ) != 0 ) {
DBGC ( image, "ElTorito %p bad Validation Entry checksum\n",
image );
return -ENOEXEC;
}
/* Read and verify the Initial/Default entry */
copy_from_user ( boot_entry, image->data,
( catalog_offset + sizeof ( validation_entry ) ),
sizeof ( *boot_entry ) );
if ( boot_entry->indicator != ELTORITO_BOOTABLE ) {
DBGC ( image, "ElTorito %p not bootable\n", image );
return -ENOEXEC;
}
if ( boot_entry->media_type != ELTORITO_NO_EMULATION ) {
DBGC ( image, "ElTorito %p cannot support media type %d\n",
image, boot_entry->media_type );
return -ENOTSUP;
}
DBGC ( image, "ElTorito %p media type %d segment %04x\n",
image, boot_entry->media_type, boot_entry->load_segment );
return 0;
}
/**
* Load El Torito virtual disk image into memory
*
* @v image El Torito file
* @v boot_entry El Torito boot entry
* @ret rc Return status code
*/
static int eltorito_load_disk ( struct image *image,
struct eltorito_boot_entry *boot_entry ) {
unsigned long start = ( boot_entry->start * ISO9660_BLKSIZE );
unsigned long length = ( boot_entry->length * ISO9660_BLKSIZE );
unsigned int load_segment;
userptr_t buffer;
int rc;
/* Sanity check */
if ( image->len < ( start + length ) ) {
DBGC ( image, "ElTorito %p virtual disk lies outside image\n",
image );
return -ENOEXEC;
}
DBGC ( image, "ElTorito %p virtual disk at %#lx+%#lx\n",
image, start, length );
/* Calculate load address */
load_segment = boot_entry->load_segment;
buffer = real_to_user ( load_segment, ( load_segment ? 0 : 0x7c00 ) );
/* Verify and prepare segment */
if ( ( rc = prep_segment ( buffer, length, length ) ) != 0 ) {
DBGC ( image, "ElTorito %p could not prepare segment: %s\n",
image, strerror ( rc ) );
return rc;
}
/* Copy image to segment */
memcpy_user ( buffer, 0, image->data, start, length );
return 0;
}
