[MIPS] Implementation of sel_ldr for MIPS architecture.

src/trusted/service_runtime/linux/nacl_bootstrap.c

Index: src/trusted/service_runtime/linux/nacl_bootstrap.c
diff --git a/src/trusted/service_runtime/linux/nacl_bootstrap.c b/src/trusted/service_runtime/linux/nacl_bootstrap.c
index 6a7537769c324f180cdf12d5e3cccfa63a1c573f..b8503184afd2d1d3af4fe1d0da32a80cd97039bb 100644
--- a/src/trusted/service_runtime/linux/nacl_bootstrap.c
+++ b/src/trusted/service_runtime/linux/nacl_bootstrap.c
@@ -264,6 +264,8 @@ static ElfW(Addr) load_elf_file(const char *filename,
     case EM_X86_64:
 #elif defined(__arm__)
     case EM_ARM:
+#elif defined(__mips__)
+    case EM_MIPS:
 #else
 # error "Don't know the e_machine value for this architecture!"
 #endif
@@ -667,6 +669,24 @@ asm(".pushsection \".text\",\"ax\",%progbits\n"
     "blx r0\n"                  /* Jump to the entry point.  */
     ".popsection"
     );
+#elif defined(__mips__)
+  asm(".pushsection \".text\",\"ax\",%progbits\n"
+    ".globl _start\n"
+    ".type _start,@function\n"
+    "_start:\n"
+    ".set noreorder\n"
+    "addiu $fp, $zero, 0\n"
+    "addiu $ra, $zero, 0\n"
+    "addiu $s8, $sp,   0\n"     /* Save starting SP in s8.  */
+    "addiu $a0, $sp,   0\n"
+    "addiu $sp, $sp, -16\n"
+    "jal   do_load\n"
+    "nop\n"
+    "addiu $sp, $s8,  0\n"      /* Restore the saved SP.  */
+    "jr    $v0\n"               /* Jump to the entry point.  */
+    "nop\n"
+    ".popsection"
+    );
 #else
 # error "Need stack-preserving _start code for this architecture!"
 #endif