avionic design with actual uboot and tooling

submodule of avionic design uboot bootloader and with included tools to
get you started , read readme.md and readme-tk1-loader.md

u-boot/cmd/portio.c

@@ -0,0 +1,145 @@
+/*
+ * (C) Copyright 2003
+ * Marc Singer, elf@buici.com
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * Port I/O Functions
+ *
+ * Copied from FADS ROM, Dan Malek (dmalek@jlc.net)
+ */
+
+#include <common.h>
+#include <command.h>
+
+/* Display values from last command.
+ * Memory modify remembered values are different from display memory.
+ */
+static uint in_last_addr, in_last_size;
+static uint out_last_addr, out_last_size, out_last_value;
+
+
+int do_portio_out (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
+{
+	uint addr = out_last_addr;
+	uint size = out_last_size;
+	uint value = out_last_value;
+
+	if (argc != 3)
+		return CMD_RET_USAGE;
+
+	if ((flag & CMD_FLAG_REPEAT) == 0) {
+		/*
+		 * New command specified.  Check for a size specification.
+		 * Defaults to long if no or incorrect specification.
+		 */
+		size = cmd_get_data_size (argv[0], 1);
+		addr = simple_strtoul (argv[1], NULL, 16);
+		value = simple_strtoul (argv[2], NULL, 16);
+	}
+#if defined (CONFIG_X86)
+
+	{
+		unsigned short port = addr;
+
+		switch (size) {
+		default:
+		case 1:
+		    {
+			unsigned char ch = value;
+			__asm__ volatile ("out %0, %%dx"::"a" (ch), "d" (port));
+		    }
+			break;
+		case 2:
+		    {
+			unsigned short w = value;
+			__asm__ volatile ("out %0, %%dx"::"a" (w), "d" (port));
+		    }
+			break;
+		case 4:
+			__asm__ volatile ("out %0, %%dx"::"a" (value), "d" (port));
+
+			break;
+		}
+	}
+
+#endif							/* CONFIG_X86 */
+
+	out_last_addr = addr;
+	out_last_size = size;
+	out_last_value = value;
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	out,	3,	1,	do_portio_out,
+	"write datum to IO port",
+	"[.b, .w, .l] port value\n    - output to IO port"
+);
+
+int do_portio_in (cmd_tbl_t * cmdtp, int flag, int argc, char * const argv[])
+{
+	uint addr = in_last_addr;
+	uint size = in_last_size;
+
+	if (argc != 2)
+		return CMD_RET_USAGE;
+
+	if ((flag & CMD_FLAG_REPEAT) == 0) {
+		/*
+		 * New command specified.  Check for a size specification.
+		 * Defaults to long if no or incorrect specification.
+		 */
+		size = cmd_get_data_size (argv[0], 1);
+		addr = simple_strtoul (argv[1], NULL, 16);
+	}
+#if defined (CONFIG_X86)
+
+	{
+		unsigned short port = addr;
+
+		switch (size) {
+		default:
+		case 1:
+		    {
+			unsigned char ch;
+			__asm__ volatile ("in %%dx, %0":"=a" (ch):"d" (port));
+
+			printf (" %02x\n", ch);
+		    }
+			break;
+		case 2:
+		    {
+			unsigned short w;
+			__asm__ volatile ("in %%dx, %0":"=a" (w):"d" (port));
+
+			printf (" %04x\n", w);
+		    }
+			break;
+		case 4:
+		    {
+			unsigned long l;
+			__asm__ volatile ("in %%dx, %0":"=a" (l):"d" (port));
+
+			printf (" %08lx\n", l);
+		    }
+			break;
+		}
+	}
+#endif	/* CONFIG_X86 */
+
+	in_last_addr = addr;
+	in_last_size = size;
+
+	return 0;
+}
+
+U_BOOT_CMD(
+	in,	2,	1,	do_portio_in,
+	"read data from an IO port",
+	"[.b, .w, .l] port\n"
+	"    - read datum from IO port"
+);