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/board/freescale/m5235evb/m5235evb.c

@@ -0,0 +1,109 @@
+/*
+ * (C) Copyright 2000-2003
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * Copyright (C) 2004-2007, 2012 Freescale Semiconductor, Inc.
+ * TsiChung Liew (Tsi-Chung.Liew@freescale.com)
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <config.h>
+#include <common.h>
+#include <asm/immap.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int checkboard(void)
+{
+	puts("Board: ");
+	puts("Freescale M5235 EVB\n");
+	return 0;
+};
+
+phys_size_t initdram(int board_type)
+{
+	sdram_t *sdram = (sdram_t *)(MMAP_SDRAM);
+	gpio_t *gpio = (gpio_t *)(MMAP_GPIO);
+	u32 dramsize, i, dramclk;
+
+	/*
+	 * When booting from external Flash, the port-size is less than
+	 * the port-size of SDRAM.  In this case it is necessary to enable
+	 * Data[15:0] on Port Address/Data.
+	 */
+	out_8(&gpio->par_ad,
+		GPIO_PAR_AD_ADDR23 | GPIO_PAR_AD_ADDR22 | GPIO_PAR_AD_ADDR21 |
+		GPIO_PAR_AD_DATAL);
+
+	/* Initialize PAR to enable SDRAM signals */
+	out_8(&gpio->par_sdram,
+		GPIO_PAR_SDRAM_SDWE | GPIO_PAR_SDRAM_SCAS |
+		GPIO_PAR_SDRAM_SRAS | GPIO_PAR_SDRAM_SCKE |
+		GPIO_PAR_SDRAM_SDCS(3));
+
+	dramsize = CONFIG_SYS_SDRAM_SIZE * 0x100000;
+	for (i = 0x13; i < 0x20; i++) {
+		if (dramsize == (1 << i))
+			break;
+	}
+	i--;
+
+	if (!(in_be32(&sdram->dacr0) & SDRAMC_DARCn_RE)) {
+		dramclk = gd->bus_clk / (CONFIG_SYS_HZ * CONFIG_SYS_HZ);
+
+		/* Initialize DRAM Control Register: DCR */
+		out_be16(&sdram->dcr, SDRAMC_DCR_RTIM_9CLKS |
+			SDRAMC_DCR_RTIM_6CLKS |
+			SDRAMC_DCR_RC((15 * dramclk) >> 4));
+
+		/* Initialize DACR0 */
+		out_be32(&sdram->dacr0,
+			SDRAMC_DARCn_BA(CONFIG_SYS_SDRAM_BASE) |
+			SDRAMC_DARCn_CASL_C1 | SDRAMC_DARCn_CBM_CMD20 |
+			SDRAMC_DARCn_PS_32);
+		asm("nop");
+
+		/* Initialize DMR0 */
+		out_be32(&sdram->dmr0,
+			((dramsize - 1) & 0xFFFC0000) | SDRAMC_DMRn_V);
+		asm("nop");
+
+		/* Set IP (bit 3) in DACR */
+		setbits_be32(&sdram->dacr0, SDRAMC_DARCn_IP);
+
+		/* Wait 30ns to allow banks to precharge */
+		for (i = 0; i < 5; i++) {
+			asm("nop");
+		}
+
+		/* Write to this block to initiate precharge */
+		*(u32 *) (CONFIG_SYS_SDRAM_BASE) = 0xA5A59696;
+
+		/*  Set RE (bit 15) in DACR */
+		setbits_be32(&sdram->dacr0, SDRAMC_DARCn_RE);
+
+		/* Wait for at least 8 auto refresh cycles to occur */
+		for (i = 0; i < 0x2000; i++) {
+			asm("nop");
+		}
+
+		/* Finish the configuration by issuing the MRS. */
+		setbits_be32(&sdram->dacr0, SDRAMC_DARCn_IMRS);
+		asm("nop");
+
+		/* Write to the SDRAM Mode Register */
+		*(u32 *) (CONFIG_SYS_SDRAM_BASE + 0x400) = 0xA5A59696;
+	}
+
+	return dramsize;
+};
+
+int testdram(void)
+{
+	/* TODO: XXX XXX XXX */
+	printf("DRAM test not implemented!\n");
+
+	return (0);
+}