From 3cb7c05906b8eb8e884013b441f352256fded011 Mon Sep 17 00:00:00 2001
From: Tobias Klauser <tklauser@distanz.ch>
Date: Wed, 10 Nov 2010 17:10:07 +0100
Subject: First bunch of rework, stil work in progress

---
 elf.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 elf.c

(limited to 'elf.c')

diff --git a/elf.c b/elf.c
new file mode 100644
index 0000000..cc90b18
--- /dev/null
+++ b/elf.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
+ *
+ * This file is part of nios2sim-ng.
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <libelf.h>
+#include <gelf.h>
+
+#include "nios2sim-ng.h"
+#include "image.h"
+
+/* not defined with libelf */
+#define EM_ALTERA_NIOS2		113
+
+/*
+ * http://elftoolchain.sourceforge.net/for-review/libelf-by-example-20100112.pdf
+ */
+
+static int elf_read_sections(Elf *e)
+{
+	Elf_Scn *scn = NULL;
+	GElf_Shdr shdr;
+	size_t shstrndx;
+	char *name;
+
+	if (elf_getshdrstrndx(e, &shstrndx) != 0) {
+		err("elf_getshdrstrndx() failed: %s\n", elf_errmsg(-1));
+		return -1;
+	}
+
+	while ((scn = elf_nextscn(e, scn)) != NULL) {
+		GElf_Phdr phdr;
+
+		if (gelf_getshdr(scn, &shdr) != &shdr) {
+			err("Couldn't get section header: %s\n", elf_errmsg(-1));
+			return -1;
+		}
+
+		if ((name = elf_strptr(e, shstrndx, shdr.sh_name)) == NULL) {
+			err("Couldn't get section name: %s\n", elf_errmsg(-1));
+			return -1;
+		}
+
+		dbg("Section %zu: %s\n", elf_ndxscn(scn), name);
+	}
+
+	return 0;
+}
+
+int elf_load(FILE *fp, const char *name, uint8_t *mem_base, size_t mem_size)
+{
+	int fd = fileno(fp);
+	int ret;
+	Elf *e;
+	GElf_Ehdr ehdr;
+	size_t n;
+
+	if (unlikely(fd < 0)) {
+		err("Couldn't get file descriptor for '%s'\n", name);
+		return -1;
+	}
+
+	if (elf_version(EV_CURRENT) == EV_NONE) {
+		err("ELF library initialization failed\n");
+		return -1;
+	}
+
+	ret = -1;
+	e = elf_begin(fd, ELF_C_READ, NULL);
+	if (unlikely(e == NULL)) {
+		err("Couldn't get ELF file handle for '%s': %s\n", name, elf_errmsg(-1));
+		goto out;
+	}
+
+	if (elf_kind(e) != ELF_K_ELF) {
+		err("'%s' is not an ELF object\n", name);
+		goto out;
+	}
+
+	if (gelf_getclass(e) != ELFCLASS32) {
+		err("'%s' has invalid ELF class\n", name);
+		goto out;
+	}
+
+	if (gelf_getehdr(e, &ehdr) == NULL) {
+		err("gelf_getehdr() failed: %s\n", elf_errmsg(-1));
+		goto out;
+	}
+
+	if (ehdr.e_type != ET_EXEC || ehdr.e_machine != EM_ALTERA_NIOS2) {
+		err("'%s' is not a Nios2 ELF executable (%x, %x)\n", name, ehdr.e_type, ehdr.e_machine);
+		goto out;
+	}
+
+	ret = elf_read_sections(e);
+out:
+	elf_end(e);
+	return ret;
+}
-- 
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