Fix UART buffering, now it works

1 files changed, 6 insertions, 0 deletions

diff --git a/app/platform/stm32f0-gcc/retarget.cpp b/app/platform/stm32f0-gcc/retarget.cpp
index a6706d3..85e12b4 100644
--- a/app/platform/stm32f0-gcc/retarget.cpp
+++ b/app/platform/stm32f0-gcc/retarget.cpp
@@ -92,6 +92,12 @@ extern "C" ssize_t read(int fd, void *buf, size_t nbytes)
     switch (file->type) {
     case FileType::kUART:
         ret = UARTRead(reinterpret_cast<UART*>(file->extra), buf, nbytes);
+        // XXX if fcntl support for disabling O_NONBLOCK will ever be added,
+        // then it has to something with this block of code
+        if (ret == 0) {
+            errno = EWOULDBLOCK;
+            ret = -1;
+        }
         break;
     case FileType::kUARTDirect:
         ret = UARTReadDirect(reinterpret_cast<UART*>(file->extra), buf, nbytes);