generic ELF loader


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1831 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/loader.c b/loader.c
new file mode 100644
index 0000000..c4bde55
--- /dev/null
+++ b/loader.c
@@ -0,0 +1,234 @@
+/*
+ * QEMU Executable loader
+ * 
+ * Copyright (c) 2006 Fabrice Bellard
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+#include "vl.h"
+#include "disas.h"
+
+/* return the size or -1 if error */
+int get_image_size(const char *filename)
+{
+    int fd, size;
+    fd = open(filename, O_RDONLY | O_BINARY);
+    if (fd < 0)
+        return -1;
+    size = lseek(fd, 0, SEEK_END);
+    close(fd);
+    return size;
+}
+
+/* return the size or -1 if error */
+int load_image(const char *filename, uint8_t *addr)
+{
+    int fd, size;
+    fd = open(filename, O_RDONLY | O_BINARY);
+    if (fd < 0)
+        return -1;
+    size = lseek(fd, 0, SEEK_END);
+    lseek(fd, 0, SEEK_SET);
+    if (read(fd, addr, size) != size) {
+        close(fd);
+        return -1;
+    }
+    close(fd);
+    return size;
+}
+
+/* A.OUT loader */
+
+struct exec
+{
+  uint32_t a_info;   /* Use macros N_MAGIC, etc for access */
+  uint32_t a_text;   /* length of text, in bytes */
+  uint32_t a_data;   /* length of data, in bytes */
+  uint32_t a_bss;    /* length of uninitialized data area, in bytes */
+  uint32_t a_syms;   /* length of symbol table data in file, in bytes */
+  uint32_t a_entry;  /* start address */
+  uint32_t a_trsize; /* length of relocation info for text, in bytes */
+  uint32_t a_drsize; /* length of relocation info for data, in bytes */
+};
+
+#ifdef BSWAP_NEEDED
+static void bswap_ahdr(struct exec *e)
+{
+    bswap32s(&e->a_info);
+    bswap32s(&e->a_text);
+    bswap32s(&e->a_data);
+    bswap32s(&e->a_bss);
+    bswap32s(&e->a_syms);
+    bswap32s(&e->a_entry);
+    bswap32s(&e->a_trsize);
+    bswap32s(&e->a_drsize);
+}
+#else
+#define bswap_ahdr(x) do { } while (0)
+#endif
+
+#define N_MAGIC(exec) ((exec).a_info & 0xffff)
+#define OMAGIC 0407
+#define NMAGIC 0410
+#define ZMAGIC 0413
+#define QMAGIC 0314
+#define _N_HDROFF(x) (1024 - sizeof (struct exec))
+#define N_TXTOFF(x)							\
+    (N_MAGIC(x) == ZMAGIC ? _N_HDROFF((x)) + sizeof (struct exec) :	\
+     (N_MAGIC(x) == QMAGIC ? 0 : sizeof (struct exec)))
+#define N_TXTADDR(x) (N_MAGIC(x) == QMAGIC ? TARGET_PAGE_SIZE : 0)
+#define N_DATOFF(x) (N_TXTOFF(x) + (x).a_text)
+#define _N_SEGMENT_ROUND(x) (((x) + TARGET_PAGE_SIZE - 1) & ~(TARGET_PAGE_SIZE - 1))
+
+#define _N_TXTENDADDR(x) (N_TXTADDR(x)+(x).a_text)
+
+#define N_DATADDR(x) \
+    (N_MAGIC(x)==OMAGIC? (_N_TXTENDADDR(x)) \
+     : (_N_SEGMENT_ROUND (_N_TXTENDADDR(x))))
+
+
+int load_aout(const char *filename, uint8_t *addr)
+{
+    int fd, size, ret;
+    struct exec e;
+    uint32_t magic;
+
+    fd = open(filename, O_RDONLY | O_BINARY);
+    if (fd < 0)
+        return -1;
+
+    size = read(fd, &e, sizeof(e));
+    if (size < 0)
+        goto fail;
+
+    bswap_ahdr(&e);
+
+    magic = N_MAGIC(e);
+    switch (magic) {
+    case ZMAGIC:
+    case QMAGIC:
+    case OMAGIC:
+	lseek(fd, N_TXTOFF(e), SEEK_SET);
+	size = read(fd, addr, e.a_text + e.a_data);
+	if (size < 0)
+	    goto fail;
+	break;
+    case NMAGIC:
+	lseek(fd, N_TXTOFF(e), SEEK_SET);
+	size = read(fd, addr, e.a_text);
+	if (size < 0)
+	    goto fail;
+	ret = read(fd, addr + N_DATADDR(e), e.a_data);
+	if (ret < 0)
+	    goto fail;
+	size += ret;
+	break;
+    default:
+	goto fail;
+    }
+    close(fd);
+    return size;
+ fail:
+    close(fd);
+    return -1;
+}
+
+/* ELF loader */
+
+static void *load_at(int fd, int offset, int size)
+{
+    void *ptr;
+    if (lseek(fd, offset, SEEK_SET) < 0)
+        return NULL;
+    ptr = qemu_malloc(size);
+    if (!ptr)
+        return NULL;
+    if (read(fd, ptr, size) != size) {
+        qemu_free(ptr);
+        return NULL;
+    }
+    return ptr;
+}
+
+
+#define ELF_CLASS   ELFCLASS32
+#include "elf.h"
+
+#define SZ		32
+#define elf_word        uint32_t
+#define bswapSZs	bswap32s
+#include "elf_ops.h"
+
+#undef elfhdr
+#undef elf_phdr
+#undef elf_shdr
+#undef elf_sym
+#undef elf_note
+#undef elf_word
+#undef bswapSZs
+#undef SZ
+#define elfhdr		elf64_hdr
+#define elf_phdr	elf64_phdr
+#define elf_note	elf64_note
+#define elf_shdr	elf64_shdr
+#define elf_sym		elf64_sym
+#define elf_word        uint64_t
+#define bswapSZs	bswap64s
+#define SZ		64
+#include "elf_ops.h"
+
+/* return < 0 if error, otherwise the number of bytes loaded in memory */
+int load_elf(const char *filename, int64_t virt_to_phys_addend)
+{
+    int fd, data_order, must_swab, ret;
+    uint8_t e_ident[EI_NIDENT];
+
+    fd = open(filename, O_RDONLY);
+    if (fd < 0) {
+        perror(filename);
+        return -1;
+    }
+    if (read(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
+        goto fail;
+    if (e_ident[0] != ELFMAG0 ||
+        e_ident[1] != ELFMAG1 ||
+        e_ident[2] != ELFMAG2 ||
+        e_ident[3] != ELFMAG3)
+        goto fail;
+#ifdef WORDS_BIGENDIAN
+    data_order = ELFDATA2MSB;
+#else
+    data_order = ELFDATA2LSB;
+#endif
+    must_swab = data_order != e_ident[EI_DATA];
+    
+    lseek(fd, 0, SEEK_SET);
+    if (e_ident[EI_CLASS] == ELFCLASS64) {
+        ret = load_elf64(fd, virt_to_phys_addend, must_swab);
+    } else {
+        ret = load_elf32(fd, virt_to_phys_addend, must_swab);
+    }
+
+    close(fd);
+    return ret;
+
+ fail:
+    close(fd);
+    return -1;
+}