X-Git-Url: http://git.joshuawise.com/netwatch.git/blobdiff_plain/c4a165640f8cbf4844426c8cea87246db3953467..86c89e89a88d25e85956b258005b52e0f2686b89:/grubload/loader.c

diff --git a/grubload/loader.c b/grubload/loader.c
new file mode 100644
index 0000000..4ecba2a
--- /dev/null
+++ b/grubload/loader.c
@@ -0,0 +1,49 @@
+#include "minilib.h"
+#include "../include/elf.h"
+
+static const unsigned char elf_ident[4] = { 0x7F, 'E', 'L', 'F' }; 
+
+int load_elf (char * buf, int size) {
+
+	Elf32_Ehdr * elf_hdr = (Elf32_Ehdr *) buf;
+	Elf32_Shdr * elf_sec_hdrs = (Elf32_Shdr *) (buf + elf_hdr->e_shoff);
+
+	/* Sanity check on ELF file */
+	if (memcmp(elf_hdr->e_ident, elf_ident, sizeof(elf_ident))) return -1;
+	if (elf_hdr->e_type != ET_EXEC) return -1;
+	if (elf_hdr->e_machine != EM_386) return -1;
+	if (elf_hdr->e_version != EV_CURRENT) return -1;
+	if (size < sizeof(Elf32_Ehdr)) return -1;
+	if (((char *)&elf_sec_hdrs[elf_hdr->e_shnum]) > (buf + size)) return -1;
+
+	char * string_table = buf + elf_sec_hdrs[elf_hdr->e_shstrndx].sh_offset;
+
+	if (string_table > (buf + size)) return -1;
+
+	int i;
+	for (i = 0; i < elf_hdr->e_shnum; i++) {
+
+		if (elf_sec_hdrs[i].sh_name == SHN_UNDEF) {
+			continue;
+		}
+
+		char * section_name = string_table + elf_sec_hdrs[i].sh_name;
+
+		if ((elf_sec_hdrs[i].sh_type != SHT_PROGBITS) || !(elf_sec_hdrs[i].sh_flags & SHF_ALLOC)) {
+			puts("Skipping ");
+			puts(section_name);
+			puts("\n");
+			continue;
+		}
+
+		puts("Loading ");
+		puts(section_name);
+		puts("\n");
+
+		memcpy(elf_sec_hdrs[i].sh_addr,
+		       buf + elf_sec_hdrs[i].sh_offset,
+		       elf_sec_hdrs[i].sh_size);
+	}
+
+	return 0;
+}