From cbac0733ee3e24a52be1cce34e969fdbd11dd766 Mon Sep 17 00:00:00 2001
From: Marek Kraus <gamelaster@outlook.com>
Date: Sat, 21 Jan 2023 14:34:46 +0100
Subject: [PATCH] Final support of flashing on macOS

For some reason, macOS have issues with USB CDC,
surprisingly, CH340G convertor works just fine.
But FTDI and Bouffalo's USB CDC didn't worked.
Basically, without writing anything, we don't receive
response from board. This was fixed by adding drain
after writing BOUFALLOLABRESET handshake + adding
drains after every commmand write. Also, for some reason,
in USB CDC, the size of USB payload is limited, else
it will fail.
---
 lib/blisp.c      |  8 ++++++++
 lib/blisp_easy.c | 24 ++++++++++++++++++------
 2 files changed, 26 insertions(+), 6 deletions(-)

diff --git a/lib/blisp.c b/lib/blisp.c
index 0375bef..3491496 100644
--- a/lib/blisp.c
+++ b/lib/blisp.c
@@ -130,6 +130,10 @@ int32_t blisp_send_command(struct blisp_device* device,
     blisp_dlog("Received error or not written all data: %d", ret);
     return BLISP_ERR_UNKNOWN;
   }
+#ifdef __APPLE__
+  sp_drain(serial_port);
+#endif
+
   return BLISP_OK;
 }
 
@@ -191,6 +195,9 @@ int32_t blisp_device_handshake(struct blisp_device* device, bool in_ef_loader) {
     if (!in_ef_loader) {
       if (device->is_usb) {
         sp_blocking_write(serial_port, "BOUFFALOLAB5555RESET\0\0", 22, 100);
+#ifdef __APPLE__
+        sp_drain(serial_port);
+#endif
       }
     }
     ret = sp_blocking_write(serial_port, handshake_buffer, bytes_count, 500);
@@ -210,6 +217,7 @@ int32_t blisp_device_handshake(struct blisp_device* device, bool in_ef_loader) {
         return BLISP_OK;
       }
     }
+
   }
   blisp_dlog("Received no response from chip.");
   return BLISP_ERR_NO_RESPONSE;
diff --git a/lib/blisp_easy.c b/lib/blisp_easy.c
index 37a9216..d0df3a8 100644
--- a/lib/blisp_easy.c
+++ b/lib/blisp_easy.c
@@ -57,17 +57,23 @@ int32_t blisp_easy_load_segment_data(
     struct blisp_easy_transport* segment_transport,
     blisp_easy_progress_callback progress_callback) {
   int32_t ret;
+#ifdef __APPLE__
+  const uint16_t buffer_max_size = 252 * 16;
+#else
+  const uint16_t buffer_max_size = 4092;
+#endif
+
 
   uint32_t sent_data = 0;
   uint32_t buffer_size = 0;
-  uint8_t buffer[4092];
+  uint8_t buffer[buffer_max_size];
 
   blisp_easy_report_progress(progress_callback, 0, segment_size);
 
   while (sent_data < segment_size) {
     buffer_size = segment_size - sent_data;
-    if (buffer_size > 4092) {
-      buffer_size = 4092;
+    if (buffer_size > buffer_max_size) {
+      buffer_size = buffer_max_size;
     }
     blisp_easy_transport_read(segment_transport, buffer,
                               buffer_size);  // TODO: Error Handling
@@ -319,15 +325,21 @@ int32_t blisp_easy_flash_write(struct blisp_device* device,
                                uint32_t data_size,
                                blisp_easy_progress_callback progress_callback) {
   int32_t ret;
+#ifdef __APPLE__
+  const uint16_t buffer_max_size = 372 * 1;
+#else
+  const uint16_t buffer_max_size = 2052;
+#endif
+
   uint32_t sent_data = 0;
   uint32_t buffer_size = 0;
-  uint8_t buffer[8184];
+  uint8_t buffer[buffer_max_size];
   blisp_easy_report_progress(progress_callback, 0, data_size);
 
   while (sent_data < data_size) {
     buffer_size = data_size - sent_data;
-    if (buffer_size > 2052) {
-      buffer_size = 2052;
+    if (buffer_size > buffer_max_size) {
+      buffer_size = buffer_max_size;
     }
     blisp_easy_transport_read(data_transport, buffer,
                               buffer_size);  // TODO: Error Handling