1 files changed, 226 insertions, 0 deletions
diff --git a/src/VBox/Devices/PC/ipxe/src/image/elf.c b/src/VBox/Devices/PC/ipxe/src/image/elf.c
new file mode 100644
index 00000000..5c2f9db2
--- /dev/null
+++ b/src/VBox/Devices/PC/ipxe/src/image/elf.c
@@ -0,0 +1,226 @@
+/*
+ * 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.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+/**
+ * @file
+ *
+ * ELF image format
+ *
+ * A "pure" ELF image is not a bootable image.  There are various
+ * bootable formats based upon ELF (e.g. Multiboot), which share
+ * common ELF-related functionality.
+ */
+
+#include <errno.h>
+#include <elf.h>
+#include <ipxe/uaccess.h>
+#include <ipxe/segment.h>
+#include <ipxe/image.h>
+#include <ipxe/elf.h>
+
+/**
+ * Load ELF segment into memory
+ *
+ * @v image		ELF file
+ * @v phdr		ELF program header
+ * @v dest		Destination address
+ * @ret rc		Return status code
+ */
+static int elf_load_segment ( struct image *image, Elf_Phdr *phdr,
+			      physaddr_t dest ) {
+	userptr_t buffer = phys_to_user ( dest );
+	int rc;
+
+	DBGC ( image, "ELF %p loading segment [%x,%x) to [%lx,%lx,%lx)\n",
+	       image, phdr->p_offset, ( phdr->p_offset + phdr->p_filesz ),
+	       dest, ( dest + phdr->p_filesz ), ( dest + 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;
+	}
+
+	/* Copy image to segment */
+	memcpy_user ( buffer, 0, image->data, phdr->p_offset, phdr->p_filesz );
+
+	return 0;
+}
+
+/**
+ * Process ELF segment
+ *
+ * @v image		ELF file
+ * @v ehdr		ELF executable header
+ * @v phdr		ELF program header
+ * @v process		Segment processor
+ * @ret entry		Entry point, if found
+ * @ret max		Maximum used address
+ * @ret rc		Return status code
+ */
+static int elf_segment ( struct image *image, Elf_Ehdr *ehdr, Elf_Phdr *phdr,
+			 int ( * process ) ( struct image *image,
+					     Elf_Phdr *phdr, physaddr_t dest ),
+			 physaddr_t *entry, physaddr_t *max ) {
+	physaddr_t dest;
+	physaddr_t end;
+	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;
+	}
+	end = ( dest + phdr->p_memsz );
+
+	/* Update maximum used address, if applicable */
+	if ( end > *max )
+		*max = end;
+
+	/* Process segment */
+	if ( ( rc = process ( image, phdr, dest ) ) != 0 )
+		return rc;
+
+	/* 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;
+}
+
+/**
+ * Process ELF segments
+ *
+ * @v image		ELF file
+ * @v ehdr		ELF executable header
+ * @v process		Segment processor
+ * @ret entry		Entry point, if found
+ * @ret max		Maximum used address
+ * @ret rc		Return status code
+ */
+int elf_segments ( struct image *image, Elf_Ehdr *ehdr,
+		   int ( * process ) ( struct image *image, Elf_Phdr *phdr,
+				       physaddr_t dest ),
+		   physaddr_t *entry, physaddr_t *max ) {
+	Elf_Phdr phdr;
+	Elf_Off phoff;
+	unsigned int phnum;
+	int rc;
+
+	/* Initialise maximum used address */
+	*max = 0;
+
+	/* Invalidate entry point */
+	*entry = 0;
+
+	/* Read and process ELF program headers */
+	for ( phoff = ehdr->e_phoff , phnum = ehdr->e_phnum ; phnum ;
+	      phoff += ehdr->e_phentsize, phnum-- ) {
+		if ( phoff > image->len ) {
+			DBGC ( image, "ELF %p program header %d outside "
+			       "image\n", image, phnum );
+			return -ENOEXEC;
+		}
+		copy_from_user ( &phdr, image->data, phoff, sizeof ( phdr ) );
+		if ( ( rc = elf_segment ( image, ehdr, &phdr, process,
+					  entry, max ) ) != 0 )
+			return rc;
+	}
+
+	/* Check for a valid execution address */
+	if ( ! *entry ) {
+		DBGC ( image, "ELF %p entry point %lx outside image\n",
+		       image, ( ( unsigned long ) ehdr->e_entry ) );
+		return -ENOEXEC;
+	}
+
+	return 0;
+}
+
+/**
+ * Load ELF image into memory
+ *
+ * @v image		ELF file
+ * @ret entry		Entry point
+ * @ret max		Maximum used address
+ * @ret rc		Return status code
+ */
+int elf_load ( struct image *image, physaddr_t *entry, physaddr_t *max ) {
+	static const uint8_t e_ident[] = {
+		[EI_MAG0]	= ELFMAG0,
+		[EI_MAG1]	= ELFMAG1,
+		[EI_MAG2]	= ELFMAG2,
+		[EI_MAG3]	= ELFMAG3,
+		[EI_CLASS]	= ELFCLASS,
+	};
+	Elf_Ehdr ehdr;
+	int rc;
+
+	/* Read ELF header */
+	copy_from_user ( &ehdr, image->data, 0, sizeof ( ehdr ) );
+	if ( memcmp ( &ehdr.e_ident[EI_MAG0], e_ident,
+		      sizeof ( e_ident ) ) != 0 ) {
+		DBGC ( image, "ELF %p has invalid signature\n", image );
+		return -ENOEXEC;
+	}
+
+	/* Load ELF segments into memory */
+	if ( ( rc = elf_segments ( image, &ehdr, elf_load_segment,
+				   entry, max ) ) != 0 )
+		return rc;
+
+	return 0;
+}