elfboot: initial version

elfboot/elfboot.c

@@ -0,0 +1,84 @@
+#include <elf.h>
+#include "test.h"
+
+#ifdef TEST
+static void *memcpy(void *dest, void *src, unsigned long len)
+{
+	dprintf("Copying %p to %p for %08ld bytes\n", src, dest, len);
+
+	return dest;
+}
+static void *memset(void *dest, int v, unsigned long len)
+{
+	dprintf("Filling %p with %02x for %08ld bytes\n", dest, (unsigned char)v, len);
+
+	return dest;
+}
+#else
+static void *memcpy(void *dest, void *src, unsigned long len)
+{
+	char *d = dest, *s = src;
+
+	for ( ; len ; len--) {
+		*(d++) = *(s++);
+	}
+
+	return d;
+}
+static void *memset(void *dest, int v, unsigned long len)
+{
+	char *d = dest;
+
+	for ( ; len ; len--) {
+		*(d++) = (char)v;
+	}
+
+	return d;
+}
+#endif
+
+static void load_programs(unsigned char *image, Elf64_Phdr *hdrs, int nhdr)
+{
+	int i;
+
+	for (i = 0; i < nhdr; i++) {
+		if (hdrs[i].p_type == PT_LOAD) {
+			dprintf("PT_LOAD : %lx: %lx - %lx (%lx)\n",
+			        hdrs[i].p_vaddr,
+			        hdrs[i].p_offset, hdrs[i].p_filesz,
+			        hdrs[i].p_memsz);
+
+			memcpy((void *)hdrs[i].p_vaddr,
+			       image + hdrs[i].p_offset,
+			       hdrs[i].p_filesz);
+			if (hdrs[i].p_filesz < hdrs[i].p_memsz) {
+				memset((void *)hdrs[i].p_vaddr + 
+				       hdrs[i].p_filesz, 0,
+				       hdrs[i].p_memsz - hdrs[i].p_filesz);
+			}
+		}
+	}
+}
+
+
+/*
+ * Return value: If success, the entry point address. Otherwise, 0.
+ */
+unsigned long elfboot_main(unsigned char *image)
+{
+	Elf64_Ehdr *hdr;
+
+	hdr = (Elf64_Ehdr *)image;
+	if (hdr->e_ident[0] != 0x7f || hdr->e_ident[1] != 'E'
+	    || hdr->e_ident[2] != 'L' || hdr->e_ident[3] != 'F') {
+		return 0;
+	}
+	/* TODO: We may overlap. So copying should be more sophisticated */
+	if (!hdr->e_phoff || hdr->e_phentsize != sizeof(Elf64_Phdr)) {
+		return 0;
+	}
+	load_programs(image, 
+	              (Elf64_Phdr *)(image + hdr->e_phoff), hdr->e_phnum);
+	return hdr->e_entry;
+}
+