Fix Exception 2 when using printf or vprintf

ets_vprintf signature is not the same as vprintf, it takes an output function as a first argument.

Author: igrr

cores/esp8266/libc_replacements.c

@@ -52,10 +52,9 @@ int ICACHE_RAM_ATTR putchar(int c) {
 }
 
 int ICACHE_RAM_ATTR printf(const char* format, ...) {
-    int ret;
     va_list arglist;
     va_start(arglist, format);
-    ret = ets_vprintf(format, arglist);
+    int ret = ets_vprintf(ets_putc, format, arglist);
     va_end(arglist);
     return ret;
 }
@@ -79,7 +78,7 @@ int ICACHE_RAM_ATTR snprintf(char* buffer, size_t size, const char* format, ...)
 }
 
 int ICACHE_RAM_ATTR vprintf(const char * format, va_list arg) {
-    return ets_vprintf(format, arg);
+    return ets_vprintf(ets_putc, format, arg);
 }
 
 int ICACHE_RAM_ATTR vsnprintf(char * buffer, size_t size, const char * format, va_list arg) {

tools/sdk/include/ets_sys.h

@@ -155,7 +155,7 @@ inline uint32_t ETS_INTR_PENDING(void)
 
 #define ETS_SDIO_INTR_DISABLE() \
     ETS_INTR_DISABLE(ETS_SDIO_INUM)
-    
+
 
 void *pvPortMalloc(size_t xWantedSize, const char* file, int line) __attribute__((malloc, alloc_size(1)));
 void *pvPortRealloc(void* ptr, size_t xWantedSize, const char* file, int line) __attribute__((alloc_size(2)));
@@ -183,7 +183,8 @@ void ets_isr_attach(int intr, int_handler_t handler, void *arg);
 void ets_intr_lock();
 void ets_intr_unlock();
 int ets_vsnprintf(char * s, size_t n, const char * format, va_list arg)  __attribute__ ((format (printf, 3, 0)));
-int ets_vprintf(const char * format, va_list arg) __attribute__ ((format (printf, 1, 0)));
+int ets_vprintf(int (*print_function)(int), const char * format, va_list arg) __attribute__ ((format (printf, 2, 0)));
+int ets_putc(int);
 bool ets_task(ETSTask task, uint8 prio, ETSEvent *queue, uint8 qlen);
 bool ets_post(uint8 prio, ETSSignal sig, ETSParam par);