Removed the Etherboot-specific ELF-image code and replaced it with a

generic ELF loader, to be used by the multiboot code.

1 files changed, 130 insertions, 0 deletions

diff --git a/src/image/elf.c b/src/image/elf.c
new file mode 100644
index 00000000..c746caa4
--- /dev/null
+++ b/src/image/elf.c
@@ -0,0 +1,130 @@
+/*
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/**
+ * @file
+ *
+ * ELF image format
+ *
+ */
+
+#include <errno.h>
+#include <elf.h>
+#include <gpxe/uaccess.h>
+#include <gpxe/segment.h>
+
+typedef Elf32_Ehdr	Elf_Ehdr;
+typedef Elf32_Phdr	Elf_Phdr;
+typedef Elf32_Off	Elf_Off;
+
+/** An ELF file */
+struct elf {
+	/** ELF file image */
+	userptr_t image;
+	/** Length of ELF file image */
+	size_t len;
+};
+
+/**
+ * Load ELF segment into memory
+ *
+ * @v elf		ELF file
+ * @v phdr		ELF program header
+ * @ret rc		Return status code
+ */
+static int elf_load_segment ( struct elf *elf, 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 ) > elf->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 [%lx,%lx) to [%lx,%lx,%lx)\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 */
+	copy_user ( buffer, 0, elf->image, phdr->p_offset, phdr->p_filesz );
+
+	return 0;
+}
+
+/**
+ * Load ELF image into memory
+ *
+ * @v elf		ELF file
+ * @ret rc		Return status code
+ */
+int elf_load ( struct elf *elf ) {
+	Elf_Ehdr ehdr;
+	Elf_Phdr phdr;
+	Elf_Off phoff;
+	unsigned int phnum;
+	int rc;
+
+	/* Read ELF header */
+	copy_from_user ( &ehdr, elf->image, 0, sizeof ( ehdr ) );
+	if ( memcmp ( &ehdr.e_ident[EI_MAG0], ELFMAG, SELFMAG ) != 0 ) {
+		DBG ( "Invalid ELF signature\n" );
+		return -ENOEXEC;
+	}
+
+	/* Read ELF program headers */
+	for ( phoff = ehdr.e_phoff , phnum = ehdr.e_phnum ; phnum ;
+	      phoff += ehdr.e_phentsize, phnum-- ) {
+		if ( phoff > elf->len ) {
+			DBG ( "ELF program header %d outside ELF image\n",
+			      phnum );
+			return -ENOEXEC;
+		}
+		copy_from_user ( &phdr, elf->image, phoff, sizeof ( phdr ) );
+		if ( ( rc = elf_load_segment ( elf, &phdr ) ) != 0 )
+			return rc;
+	}
+
+	return 0;
+}