esp8266: Update to SDK version 1.1.0 (MIT-licensed).

1. Updated linker script, now user app appears to contain exception vector
table and oesn't work (faults) without it.
2. Commened out support for GPIO pulldown, which was removed in this SDK
version without clear explanation, but apparently because it was released
without proper validation, and now turns out it doesn't work as expected,
or there's a different function there.

esp8266/esp8266.ld

@@ -21,6 +21,11 @@ PHDRS
 }
 
 ENTRY(call_user_start)
+EXTERN(_DebugExceptionVector)
+EXTERN(_DoubleExceptionVector)
+EXTERN(_KernelExceptionVector)
+EXTERN(_NMIExceptionVector)
+EXTERN(_UserExceptionVector)
 
 PROVIDE(_memmap_vecbase_reset = 0x40000000);
 
@@ -101,6 +106,30 @@ SECTIONS
     {
         _stext = .;
         _text_start = ABSOLUTE(.);
+        *(.UserEnter.text)
+        . = ALIGN(16);
+        *(.DebugExceptionVector.text)
+        . = ALIGN(16);
+        *(.NMIExceptionVector.text)
+        . = ALIGN(16);
+        *(.KernelExceptionVector.text)
+        LONG(0)
+        LONG(0)
+        LONG(0)
+        LONG(0)
+        . = ALIGN(16);
+        *(.UserExceptionVector.text)
+        LONG(0)
+        LONG(0)
+        LONG(0)
+        LONG(0)
+        . = ALIGN(16);
+        *(.DoubleExceptionVector.text)
+        LONG(0)
+        LONG(0)
+        LONG(0)
+        LONG(0)
+        . = ALIGN (16);
         *(.entry.text)
         *(.init.literal)
         *(.init)

esp8266/modpybpin.c

@@ -40,7 +40,8 @@
 #define GPIO_MODE_OUTPUT (1)
 #define GPIO_PULL_NONE (0)
 #define GPIO_PULL_UP (1)
-#define GPIO_PULL_DOWN (2)
+// Removed in SDK 1.1.0
+//#define GPIO_PULL_DOWN (2)
 
 typedef struct _pyb_pin_obj_t {
     mp_obj_base_t base;
@@ -91,15 +92,20 @@ STATIC mp_obj_t pyb_pin_obj_init_helper(pyb_pin_obj_t *self, mp_uint_t n_args, c
 
     // configure the GPIO as requested
     PIN_FUNC_SELECT(self->periph, self->func);
+    #if 0
+    // Removed in SDK 1.1.0
     if ((pull & GPIO_PULL_DOWN) == 0) {
         PIN_PULLDWN_DIS(self->periph);
     }
+    #endif
     if ((pull & GPIO_PULL_UP) == 0) {
         PIN_PULLUP_DIS(self->periph);
     }
+    #if 0
     if ((pull & GPIO_PULL_DOWN) != 0) {
         PIN_PULLDWN_EN(self->periph);
     }
+    #endif
     if ((pull & GPIO_PULL_UP) != 0) {
         PIN_PULLUP_EN(self->periph);
     }
@@ -191,7 +197,7 @@ STATIC const mp_map_elem_t pyb_pin_locals_dict_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR_OUT_PP),    MP_OBJ_NEW_SMALL_INT(GPIO_MODE_OUTPUT) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_NONE), MP_OBJ_NEW_SMALL_INT(GPIO_PULL_NONE) },
     { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_UP),   MP_OBJ_NEW_SMALL_INT(GPIO_PULL_UP) },
-    { MP_OBJ_NEW_QSTR(MP_QSTR_PULL_DOWN), MP_OBJ_NEW_SMALL_INT(GPIO_PULL_DOWN) },
+    //{ MP_OBJ_NEW_QSTR(MP_QSTR_PULL_DOWN), MP_OBJ_NEW_SMALL_INT(GPIO_PULL_DOWN) },
 };
 
 STATIC MP_DEFINE_CONST_DICT(pyb_pin_locals_dict, pyb_pin_locals_dict_table);