1 files changed, 46 insertions, 0 deletions
diff --git a/riscv/load_elf.cc b/riscv/load_elf.cc
new file mode 100644
index 0000000..c4f56f3
--- /dev/null
+++ b/riscv/load_elf.cc
@@ -0,0 +1,46 @@
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <elf.h>
+#include "common.h"
+#include "load_elf.h"
+
+void load_elf(const char* buf, size_t size, loader_t* loader)
+{
+  demand(size >= sizeof(Elf64_Ehdr), "truncated ELF!");
+  const Elf64_Ehdr* eh = (const Elf64_Ehdr*)buf;
+
+  const uint32_t* magic = (const uint32_t*)eh->e_ident;
+  demand(*magic == *(const uint32_t*)ELFMAG, "not a host-endian ELF!");
+  demand(size >= eh->e_phoff + eh->e_phnum*sizeof(Elf64_Phdr), "bad ELF!");
+  const Elf64_Phdr* phs = (const Elf64_Phdr*)(buf+eh->e_phoff);
+
+  for(int i = 0; i < eh->e_phnum; i++)
+  {
+    const Elf64_Phdr* ph = &phs[i];
+    if(ph->p_type == SHT_PROGBITS && ph->p_memsz)
+    {
+      demand(size >= ph->p_offset + ph->p_filesz, "truncated ELF!");
+      demand(ph->p_memsz >= ph->p_filesz, "bad ELF!");
+
+      loader->write(ph->p_vaddr, ph->p_filesz, buf + ph->p_offset);
+      loader->write(ph->p_vaddr + ph->p_filesz, ph->p_memsz - ph->p_filesz);
+    }
+  }
+}
+
+void load_elf(const char* fn, loader_t* loader)
+{
+  int fd = open(fn, O_RDONLY);
+  demand(fd != -1, "couldn't open %s", fn);
+
+  struct stat s;
+  demand(fstat(fd,&s) != -1, "couldn't stat %s", fn);
+
+  char* addr = (char*)mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+  demand(addr != MAP_FAILED, "couldn't mmap %s", fn);
+
+  close(fd);
+
+  load_elf(addr, s.st_size, loader);
+}