[USER] Load and run ELF module in userspace

kernel/proc/elf.c

@@ -0,0 +1,75 @@
+#include <stdint.h>
+#include <string.h>
+#include <mem.h>
+#include <debug.h>
+#include <process.h>
+
+typedef struct
+{
+  uint8_t identity[16];
+  uint16_t type;
+  uint16_t machine;
+  uint32_t version;
+  uint64_t entry;
+  uint64_t ph_offset;
+  uint64_t sh_offset;
+  uint32_t flags;
+  uint16_t header_size;
+  uint16_t ph_size;
+  uint16_t ph_num;
+  uint16_t sh_size;
+  uint16_t sh_num;
+  uint16_t strtab_index;
+}__attribute__((packed)) elf_header;
+
+#define ELF_TYPE_EXECUTABLE 2
+
+typedef struct
+{
+  uint32_t type;
+  uint32_t flags;
+  uint64_t offset;
+  uint64_t virtual_address;
+  uint64_t physical_address;
+  uint64_t file_size;
+  uint64_t mem_size;
+  uint64_t align;
+}__attribute__((packed)) elf_phead;
+
+#define ELF_PT_LOAD 1
+
+void load_elf_segment(process_t *p, uint8_t *file, elf_phead *phead)
+{
+  uint64_t memsize = phead->mem_size;
+  uint64_t filesize = phead->file_size;
+  uint64_t mempos = phead->virtual_address;
+  uint64_t filepos = phead->offset;
+  debug("  Load segment %x to %x-%x\n", filepos, mempos, mempos+memsize);
+
+  procmm_map(p->mmap, mempos, mempos+memsize, 0);
+  vmm_p4_memcpy(p->mmap->P4, (void *)mempos, 0, &file[filepos], filesize);
+  vmm_p4_memset(p->mmap->P4, incptr(mempos, filesize), 0, memsize - filesize);
+}
+
+void *load_elf(process_t *p, void *data)
+{
+  elf_header *elf = data;
+  if(memcmp(elf->identity, "\x7f""ELF", 4))
+  {
+    debug_error("ELF - No elf magic at %x\n", elf->identity);
+    return 0;
+  }
+  if(elf->type != ELF_TYPE_EXECUTABLE)
+    return 0;
+
+  debug_info("ELF - Loading ELF executable\n");
+  elf_phead *phead = incptr(data, elf->ph_offset);
+  for(uint32_t i = 0; i < elf->ph_num; i++)
+  {
+    if(phead[i].type == ELF_PT_LOAD)
+    {
+      load_elf_segment(p, data, &phead[i]);
+    }
+  }
+  return (void *)elf->entry;
+}

kernel/proc/exec_elf.c

@@ -0,0 +1,14 @@
+#include <elf.h>
+#include <stdint.h>
+#include <debug.h>
+
+thread_t *exec_elf(process_t *p, void *image)
+{
+  void *entry = load_elf(p, image);
+  debug("Address:%x\n", entry);
+  procmm_setup(p);
+  thread_t *th = new_thread((void *)entry, 1);
+  process_attach(p, th);
+
+  return th;
+}