configs/makerlisp: Add VGA initialization logic.

configs/makerlisp/Kconfig

@@ -5,4 +5,11 @@
 
 if ARCH_BOARD_MAKERLISP
 
+config MAKERLISP_VGA
+	bool "VGA Controller attached?"
+	default n
+	---help---
+		Select this option if you have an I/O Controller and a VGA vide card
+		connected.
+
 endif # ARCH_BOARD_MAKERLISP

configs/makerlisp/README.txt

@@ -160,8 +160,9 @@ Serial Keyboard and VGA Display
         expansion board GPIO PB1.
      e. Transmit 'TX' pin on VGA board to USB keyboard controller 'R'
 
-     TBD:  Beyond the simple UART interface, what additional support for the
-           ready pin 'C' is required.
+     To use the VGA display controller with stdout and stderr, you also
+     need to selection CONFIG_MAKERLISP_VGA=y in your configuration.  This
+     enables a required VGA initialization sequence.
 
   2. USB keyboard controller (UART0 RX)
 
@@ -289,7 +290,9 @@ Configuration Subdirectories
 
        The default baud setting is 57600N1.
 
-       TBD:  Although the UART0 is the same with the VGA and Keyboard
-             controller boards, this configuration may not compatible with
-             those accessories.  Those may require additional support for
-             the VGA data ready pin.  A BAUD mismatch is also likely.
+       To use the VGA display controller with stdout and stderr, you also
+       need to selection CONFIG_MAKERLISP_VGA=y in your configuration.  This
+       enables a required VGA initialization sequence.
+
+       TBD:  What is the UART configuration when used with the VGA and
+       Keyboard controllers?

configs/makerlisp/src/ez80_bringup.c

@@ -68,11 +68,10 @@ int ez80_bringup(void)
 #ifdef CONFIG_FS_PROCFS
   /* Mount the procfs file system */
 
-  ret = mount(NULL, STM32_PROCFS_MOUNTPOINT, "procfs", 0, NULL);
+  ret = mount(NULL, "/proc", "procfs", 0, NULL);
   if (ret < 0)
     {
-      serr("ERROR: Failed to mount procfs at %s: %d\n",
-           STM32_PROCFS_MOUNTPOINT, ret);
+      serr("ERROR: Failed to mount procfs at /proc: %d\n", ret);
     }
 #endif
 

configs/makerlisp/src/ez80_lowinit.c

@@ -4,7 +4,8 @@
  *   Copyright (C) 2019 Gregory Nutt. All rights reserved.
  *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
- * Based upon sample code included with the Zilog ZDS-II toolchain.
+ * Parts of this file are based on MakerLisp sample code by Luther Johnson
+ * which has a compatible MIT license
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -47,6 +48,7 @@
 #include <arch/chip/io.h>
 
 #include "chip.h"
+#include "up_internal.h"
 #include "makerlisp.h"
 
 /****************************************************************************
@@ -55,6 +57,66 @@
 
 bool g_ebpresent = false;  /* True:  I/O Expansion board is present */
 
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+#define VGA_MAX_DELAY 2000000
+
+/****************************************************************************
+ * Private Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: ez80_vga_initialize
+ *
+ * Description:
+ *   If CONFIG_MAKERLISP_VGA is defined and the I/O controller is attached,
+ *   then initialize the VGA interface.
+ *
+ ****************************************************************************/
+
+#ifdef CONFIG_MAKERLISP_VGA
+static void ez80_vga_initialize(void)
+{
+  /* I/O Expansion board attached? */
+
+  if (g_ebpresent)
+    {
+      bool vgapresent = false;
+      int delay;
+
+      /* Wait for VGA ready */
+
+      for (delay = 0; delay < VGA_MAX_DELAY; delay++)
+       {
+          if *(inp(EZ80_PB_DR) & EZ80_GPIOD1) != 0)
+            {
+              vgapresent = true;
+              break;
+            }
+        }
+
+      /* Is VGA ready (and, hence, present)? */
+
+      if (vgapresent)
+        {
+          /* Yes.. set newline mode, graphic attributes:
+           *
+           * \033 = ESCAPE character
+           * Assumption:  VGA is on the console UART.
+           */
+
+          up_puts("\033[20h\033[0m");
+
+          /* Clear, home cursor, beep */
+
+          up_puts("\033[2J\033[H\a");
+        }
+    }
+}
+#endif
+
 /****************************************************************************
  * Public Functions
  ****************************************************************************/
@@ -136,6 +198,15 @@ void ez80_lowinit(void)
   /* Wait for the SD card to power up */
 
   up_udelay(750);
+
+#ifdef CONFIG_MAKERLISP_VGA
+  /* Initialize the VGA interface.  We want to do this as early as possible
+   * in the boot-up sequence.  Debug output prior initializing VGA will be
+   * lost.
+   */
+
+  ez80_vga_initialize();
+#endif
 }
 
 /****************************************************************************