Elf loader added

1 files changed, 31 insertions, 0 deletions

diff --git a/src/stem/linker/elf.c b/src/stem/linker/elf.c
new file mode 100644
index 0000000..62030ee
--- /dev/null
+++ b/src/stem/linker/elf.c
@@ -0,0 +1,31 @@
+#include "elf.h"
+#include <mem/paging.h>
+#include <mem/seg.h>
+#include <stdlib.h>
+
+int elf_check(uint8_t *data) {
+	struct elf_ehdr *h = (struct elf_ehdr*)data;
+	if (h->e_ident[0] == 0x7F && h->e_ident[1] == 'E' && h->e_ident[2] == 'L' && h->e_ident[3] == 'F') return 0;
+	return 1;
+}
+
+thread_entry elf_load(uint8_t *data, struct process* process) {
+	struct elf_ehdr *ehdr = (struct elf_ehdr*)data;
+	struct elf_phdr *phdr;
+	int i;
+	if (elf_check(data)) return 0;
+
+	pagedir_switch(process->pagedir);
+
+	phdr = (struct elf_phdr*)((uint8_t*)(data + ehdr->e_phoff));
+	for (i = 0; i < ehdr->e_phnum; i++) {
+		if (phdr[i].p_type == PT_LOAD) {
+			seg_map(simpleseg_make(phdr[i].p_vaddr, phdr[i].p_memsz, (phdr[i].p_flags & PF_W) != 0), process->pagedir);
+			memcpy((uint8_t*)phdr[i].p_vaddr, data + phdr[i].p_offset, phdr[i].p_filesz);
+			if (phdr[i].p_memsz > phdr[i].p_filesz) {
+				memset((uint8_t*)phdr[i].p_vaddr + phdr[i].p_memsz, 0, phdr[i].p_memsz - phdr[i].p_filesz);
+			}
+		}
+	}
+	return (thread_entry)ehdr->e_entry;
+}