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/common/env_nvram.c

@@ -0,0 +1,114 @@
+/*
+ * (C) Copyright 2000-2010
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * (C) Copyright 2001 Sysgo Real-Time Solutions, GmbH <www.elinos.com>
+ * Andreas Heppel <aheppel@sysgo.de>
+
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * 09-18-2001 Andreas Heppel, Sysgo RTS GmbH <aheppel@sysgo.de>
+ *
+ * It might not be possible in all cases to use 'memcpy()' to copy
+ * the environment to NVRAM, as the NVRAM might not be mapped into
+ * the memory space. (I.e. this is the case for the BAB750). In those
+ * cases it might be possible to access the NVRAM using a different
+ * method. For example, the RTC on the BAB750 is accessible in IO
+ * space using its address and data registers. To enable usage of
+ * NVRAM in those cases I invented the functions 'nvram_read()' and
+ * 'nvram_write()', which will be activated upon the configuration
+ * #define CONFIG_SYS_NVRAM_ACCESS_ROUTINE. Note, that those functions are
+ * strongly dependent on the used HW, and must be redefined for each
+ * board that wants to use them.
+ */
+
+#include <common.h>
+#include <command.h>
+#include <environment.h>
+#include <linux/stddef.h>
+#include <search.h>
+#include <errno.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
+extern void *nvram_read(void *dest, const long src, size_t count);
+extern void nvram_write(long dest, const void *src, size_t count);
+env_t *env_ptr;
+#else
+env_t *env_ptr = (env_t *)CONFIG_ENV_ADDR;
+#endif
+
+char *env_name_spec = "NVRAM";
+
+#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
+uchar env_get_char_spec(int index)
+{
+	uchar c;
+
+	nvram_read(&c, CONFIG_ENV_ADDR + index, 1);
+
+	return c;
+}
+#endif
+
+void env_relocate_spec(void)
+{
+	char buf[CONFIG_ENV_SIZE];
+
+#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
+	nvram_read(buf, CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
+#else
+	memcpy(buf, (void *)CONFIG_ENV_ADDR, CONFIG_ENV_SIZE);
+#endif
+	env_import(buf, 1);
+}
+
+int saveenv(void)
+{
+	env_t	env_new;
+	int	rcode = 0;
+
+	rcode = env_export(&env_new);
+	if (rcode)
+		return rcode;
+
+#ifdef CONFIG_SYS_NVRAM_ACCESS_ROUTINE
+	nvram_write(CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE);
+#else
+	if (memcpy((char *)CONFIG_ENV_ADDR, &env_new, CONFIG_ENV_SIZE) == NULL)
+		rcode = 1;
+#endif
+	return rcode;
+}
+
+/*
+ * Initialize Environment use
+ *
+ * We are still running from ROM, so data use is limited
+ */
+int env_init(void)
+{
+#if defined(CONFIG_SYS_NVRAM_ACCESS_ROUTINE)
+	ulong crc;
+	uchar data[ENV_SIZE];
+
+	nvram_read(&crc, CONFIG_ENV_ADDR, sizeof(ulong));
+	nvram_read(data, CONFIG_ENV_ADDR + sizeof(ulong), ENV_SIZE);
+
+	if (crc32(0, data, ENV_SIZE) == crc) {
+		gd->env_addr	= (ulong)CONFIG_ENV_ADDR + sizeof(long);
+#else
+	if (crc32(0, env_ptr->data, ENV_SIZE) == env_ptr->crc) {
+		gd->env_addr	= (ulong)&env_ptr->data;
+#endif
+		gd->env_valid	= 1;
+	} else {
+		gd->env_addr	= (ulong)&default_environment[0];
+		gd->env_valid	= 0;
+	}
+
+	return 0;
+}