From 88e1612c09f79c4b66b447cf0afa37d528bfbd39 Mon Sep 17 00:00:00 2001
From: Hector Martin <marcan@marcan.st>
Date: Sat, 17 Apr 2021 16:25:48 +0900
Subject: [PATCH] uartproxy: s/CRCERR/CSUMERR/ and actually use it

It's not a CRC.

Signed-off-by: Hector Martin <marcan@marcan.st>
---
 proxyclient/proxy.py |  6 +++---
 src/uartproxy.c      | 19 +++++++++++++------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/proxyclient/proxy.py b/proxyclient/proxy.py
index 3d99fc06..004480b9 100755
--- a/proxyclient/proxy.py
+++ b/proxyclient/proxy.py
@@ -75,7 +75,7 @@ class UartInterface:
     ST_BADCMD = -1
     ST_INVAL = -2
     ST_XFERERR = -3
-    ST_CRCERR = -4
+    ST_CSUMERR = -4
 
     CMD_LEN = 56
     REPLY_LEN = 36
@@ -200,7 +200,7 @@ class UartInterface:
                     raise UartRemoteError("Reply error: Invalid argument")
                 elif status == self.ST_XFERERR:
                     raise UartRemoteError("Reply error: Data transfer failed")
-                elif status == self.ST_CRCERR:
+                elif status == self.ST_CSUMERR:
                     raise UartRemoteError("Reply error: Data checksum failed")
                 else:
                     raise UartRemoteError("Reply error: Unknown error (%d)"%status)
@@ -250,7 +250,7 @@ class UartInterface:
             chexdump(data)
         ccsum = self.checksum(data)
         if checksum != ccsum:
-            raise UartCRCError("Reply data checksum error: Expected 0x%08x, got 0x%08x"%(checksum, ccsum))
+            raise UartChecksumError("Reply data checksum error: Expected 0x%08x, got 0x%08x"%(checksum, ccsum))
         return data
 
     def readstruct(self, addr, stype):
diff --git a/src/uartproxy.c b/src/uartproxy.c
index cc98fe23..4632d9ee 100644
--- a/src/uartproxy.c
+++ b/src/uartproxy.c
@@ -44,11 +44,11 @@ typedef struct {
 #define REQ_MEMWRITE 0x03AA55FF
 #define REQ_BOOT     0x04AA55FF
 
-#define ST_OK     0
-#define ST_BADCMD -1
-#define ST_INVAL  -2
-#define ST_XFRERR -3
-#define ST_CRCERR -4
+#define ST_OK      0
+#define ST_BADCMD  -1
+#define ST_INVAL   -2
+#define ST_XFRERR  -3
+#define ST_CSUMERR -4
 
 // I just totally pulled this out of my arse
 // Noinline so that this can be bailed out by exc_guard = EXC_RETURN
@@ -95,8 +95,15 @@ void uartproxy_run(void)
         bytes = uart_read((&request.type) + 1, REQ_SIZE - 4);
         if (bytes != REQ_SIZE - 4)
             continue;
-        if (checksum(&(request.type), REQ_SIZE - 4) != request.checksum)
+
+        if (checksum(&(request.type), REQ_SIZE - 4) != request.checksum) {
+            memset(&reply, 0, sizeof(reply));
+            reply.type = request.type;
+            reply.status = ST_CSUMERR;
+            reply.checksum = checksum(&reply, REPLY_SIZE - 4);
+            uart_write(&reply, REPLY_SIZE);
             continue;
+        }
 
         memset(&reply, 0, sizeof(reply));
         reply.type = request.type;