serial_transfer: increase serial line speed to 312500 bps

Interestingly, this did not cause a perceptible improvement in the
overall data transfer rate.

client.py

@@ -8,7 +8,7 @@ dest = 0xac02_0000
 
 ret = []
 
-def sync(ser, b, wait=0.5):
+def sync(ser, b, wait=0.1):
     l = []
     for i, c in enumerate(b):
         if i % 32 == 0 and i != 0:
@@ -17,11 +17,11 @@ def sync(ser, b, wait=0.5):
         ser.write(bytes([c]))
         time.sleep(1000 / 1000000)
         if ser.in_waiting == 0:
-            time.sleep(0.01)
+            time.sleep(0.001)
         while ser.in_waiting > 0:
             res = ser.read(ser.in_waiting)
             l.extend(res)
-            time.sleep(0.01)
+            time.sleep(0.001)
 
     time.sleep(wait)
     res = ser.read(ser.in_waiting)
@@ -42,7 +42,7 @@ def symmetric(ser, b):
             if len(l) + 8 >= i:
                 break
             else:
-                time.sleep(0.001)
+                time.sleep(0.0001)
 
         ser.write(bytes([c]))
 
@@ -98,7 +98,8 @@ def console(ser):
 with open(sys.argv[1], 'rb') as f:
     b = f.read()
 
-with serial.Serial('/dev/ttyUSB0', 120192, timeout=1) as ser:
+#with serial.Serial('/dev/ttyUSB0', 120192, timeout=1) as ser:
+with serial.Serial('/dev/ttyUSB0', 312500, timeout=1) as ser:
     #console(ser)
     print("waiting: ", end=' ')
     sys.stdout.flush()

example/serial_transfer.cpp

@@ -2,7 +2,7 @@
 
 #include "sh7091/sh7091.hpp"
 #include "sh7091/sh7091_bits.hpp"
-#include "sh7091/cache.hpp"
+#include "sh7091/serial.hpp"
 
 #include "serial_load.hpp"
 
@@ -11,14 +11,7 @@ extern uint32_t __bss_link_end __asm("__bss_link_end");
 
 void main()
 {
-  cache::init();
+  serial::init(4);
-
-  uint32_t * start = &__bss_link_start;
-  uint32_t * end = &__bss_link_end;
-  while (start < end) {
-    *start++ = 0;
-  }
-
   load_init();
 
   while (1) {

serial_load.cpp

@@ -120,8 +120,8 @@ void load_recv(uint8_t c)
       debug("prejump\n");
       holly.VO_BORDER_COL = (31 << 11);
       void (*fptr)(void) = (void (*)(void))state.addr1;
-      holly.VO_BORDER_COL = (63 << 5) | (31 << 0);
       fptr();
+      holly.VO_BORDER_COL = (63 << 5) | (31 << 0);
       debug("postjump\n");
       return;
       break;