A horror hack for merging the .text and .rodata sections in elf

binaries so that we can use objcopy to convert them to a.out.

1 files changed, 109 insertions, 0 deletions

diff --git a/sys/arch/sparc/stand/common/clean-elf.c b/sys/arch/sparc/stand/common/clean-elf.c
new file mode 100644
index 00000000000..b7a3b240589
--- /dev/null
+++ b/sys/arch/sparc/stand/common/clean-elf.c
@@ -0,0 +1,109 @@
+/*	$OpenBSD: clean-elf.c,v 1.1 2002/08/11 12:19:47 art Exp $	*/
+/*
+ * Public domain. I don't even want my name on this.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <err.h>
+#include <elf_abi.h>
+#include <fcntl.h>
+
+int
+elf_is_okay(Elf_Ehdr *ehdr)
+{
+	int retval = 0;
+
+	/*
+	 * We need to check magic, class size, endianess,
+	 * and version before we look at the rest of the
+	 * Elf_Ehdr structure.  These few elements are
+	 * represented in a machine independant fashion.
+	 */
+
+	if (IS_ELF(*ehdr) &&
+	    ehdr->e_ident[EI_CLASS] == ELF_TARG_CLASS &&
+	    ehdr->e_ident[EI_DATA] == ELF_TARG_DATA &&
+	    ehdr->e_ident[EI_VERSION] == ELF_TARG_VER) {
+		/* Now check the machine dependant header */
+		if (ehdr->e_machine == ELF_TARG_MACH &&
+		    ehdr->e_version == ELF_TARG_VER)
+			retval = 1;
+	}
+
+	return retval;
+}
+
+void
+cleanit(caddr_t addr)
+{
+	Elf_Ehdr *ehdr;
+	Elf_Shdr *shdr;
+	char *strtab;
+	int i;
+
+	ehdr = (Elf_Ehdr *)addr;
+	shdr = (Elf_Shdr *)(addr + ehdr->e_shoff);
+
+	strtab = shdr[ehdr->e_shstrndx].sh_offset + addr;
+
+	/*
+	 * Simple. find a .text section, verify that the next section is
+	 * .rodata and merge them.
+	 */
+
+	for (i = 0; i < ehdr->e_shnum; i++) {
+		Elf_Shdr *t = &shdr[i];
+		Elf_Shdr *r = &shdr[i + 1];
+
+#if 0
+		printf("foo: %s %d\n", strtab + t->sh_name, t->sh_type);
+		continue;
+#endif
+		if (strcmp(strtab + t->sh_name, ".text"))
+			continue;
+		if (strcmp(strtab + r->sh_name, ".rodata"))
+			errx(1, "sorry, rodata merge not possible.");
+
+		t->sh_size += r->sh_size + (r->sh_offset - t->sh_offset - t->sh_size);
+		r->sh_type = SHT_NULL;
+		r->sh_name = 0;
+	}
+}
+
+int
+main(int argc, char **argv)
+{
+	int fd;
+	void *addr;
+	off_t len;
+	int pgsz = getpagesize();
+
+	if (argc != 2)
+		errx(1, "usage");
+
+	if ((fd = open(argv[1], O_RDWR)) < 0)
+		err(1, "open");
+
+	if ((len = lseek(fd, 0, SEEK_END)) < 0)
+		err(1, "lseek");
+
+	len = ((len + pgsz - 1) & ~(pgsz - 1));
+
+	if ((addr = mmap(0, len, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0)) ==
+	    MAP_FAILED)
+		err(1, "mmap");
+
+	if (!elf_is_okay((Elf_Ehdr *)addr))
+		errx(1, "not an elf file");
+
+	cleanit(addr);
+
+	msync(addr, len, MS_SYNC|MS_INVALIDATE);
+
+	close(fd);
+	return (0);
+}
+