1 files changed, 36 insertions, 5 deletions
diff --git a/cros_ec/chip_stub/ec_uart.c b/cros_ec/chip_stub/ec_uart.c
index f76691169a..744e964f4a 100644
--- a/cros_ec/chip_stub/ec_uart.c
+++ b/cros_ec/chip_stub/ec_uart.c
@@ -3,39 +3,70 @@
  * found in the LICENSE file.
  */
 
-/* UART module for Chrome EC, empty implementation */
+/* UART module for Chrome EC, emulated/linux implementation */
+
+#include <stdio.h>
+#include <stdarg.h>
 
 #include "ec_uart.h"
 
 
+static void (*uart_input_callback)(void) = NULL;
+static int uart_input_callback_char = -1;
+static FILE *uart_stream = NULL;
+
+
+EcError EcUartInit(void) {
+  uart_stream = stdout;
+  return EC_SUCCESS;
+}
+
+
 EcError EcUartPrintf(const char* format, ...) {
-  return EC_ERROR_UNIMPLEMENTED;
+  va_list args;
+
+  va_start(args, format);
+  /* TODO; for now, printf() will be pretty close */
+  /* TODO: fixed-sizes for integers won't work because int is 64-bit
+   * by default on desktop Linux.  I don't distinguish between %d
+   * (int) and %d (int32_t). */
+  /* TODO: support for pointers (%p) */
+  vfprintf(uart_stream, format, args);
+  va_end(args);
+
+  return EC_SUCCESS;
 }
 
 
 EcError EcUartPuts(const char* outstr) {
-  return EC_ERROR_UNIMPLEMENTED;
+  fputs(outstr, uart_stream);
+  return EC_SUCCESS;
 }
 
 
-void EcUartFlush(void) {
+void EcUartFlushOutput(void) {
+  fflush(uart_stream);
 }
 
 
 void EcUartFlushInput(void) {
+  /* TODO */
 }
 
 
 int EcUartPeek(int c) {
+  /* TODO */
   return -1;
 }
 
 
 int EcUartGets(char* dest, int size) {
-  *dest = 0;
+  /* TODO */
   return 0;
 }
 
 
 void EcUartRegisterHasInputCallback(UartHasInputCallback callback, int c) {
+  uart_input_callback = callback;
+  uart_input_callback_char = c;
 }