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/fs/fat/Makefile

@@ -0,0 +1,11 @@
+#
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_FS_FAT)	:= fat.o
+obj-$(CONFIG_FAT_WRITE):= fat_write.o
+
+ifndef CONFIG_SPL_BUILD
+obj-$(CONFIG_FS_FAT)	+= file.o
+endif

u-boot/fs/fat/file.c

@@ -0,0 +1,183 @@
+/*
+ * file.c
+ *
+ * Mini "VFS" by Marcus Sundberg
+ *
+ * 2002-07-28 - rjones@nexus-tech.net - ported to ppcboot v1.1.6
+ * 2003-03-10 - kharris@nexus-tech.net - ported to uboot
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <config.h>
+#include <malloc.h>
+#include <fat.h>
+#include <linux/stat.h>
+#include <linux/time.h>
+
+/* Supported filesystems */
+static const struct filesystem filesystems[] = {
+	{ file_fat_detectfs,  file_fat_ls,  file_fat_read,  "FAT" },
+};
+#define NUM_FILESYS	(sizeof(filesystems)/sizeof(struct filesystem))
+
+/* The filesystem which was last detected */
+static int current_filesystem = FSTYPE_NONE;
+
+/* The current working directory */
+#define CWD_LEN		511
+char file_cwd[CWD_LEN+1] = "/";
+
+const char *
+file_getfsname(int idx)
+{
+	if (idx < 0 || idx >= NUM_FILESYS)
+		return NULL;
+
+	return filesystems[idx].name;
+}
+
+static void
+pathcpy(char *dest, const char *src)
+{
+	char *origdest = dest;
+
+	do {
+		if (dest-file_cwd >= CWD_LEN) {
+			*dest = '\0';
+			return;
+		}
+		*(dest) = *(src);
+		if (*src == '\0') {
+			if (dest-- != origdest && ISDIRDELIM(*dest)) {
+				*dest = '\0';
+			}
+			return;
+		}
+		++dest;
+
+		if (ISDIRDELIM(*src))
+			while (ISDIRDELIM(*src)) src++;
+		else
+			src++;
+	} while (1);
+}
+
+int
+file_cd(const char *path)
+{
+	if (ISDIRDELIM(*path)) {
+		while (ISDIRDELIM(*path)) path++;
+		strncpy(file_cwd+1, path, CWD_LEN-1);
+	} else {
+		const char *origpath = path;
+		char *tmpstr = file_cwd;
+		int back = 0;
+
+		while (*tmpstr != '\0') tmpstr++;
+		do {
+			tmpstr--;
+		} while (ISDIRDELIM(*tmpstr));
+
+		while (*path == '.') {
+			path++;
+			while (*path == '.') {
+				path++;
+				back++;
+			}
+			if (*path != '\0' && !ISDIRDELIM(*path)) {
+				path = origpath;
+				back = 0;
+				break;
+			}
+			while (ISDIRDELIM(*path)) path++;
+			origpath = path;
+		}
+
+		while (back--) {
+			/* Strip off path component */
+			while (!ISDIRDELIM(*tmpstr)) {
+				tmpstr--;
+			}
+			if (tmpstr == file_cwd) {
+				/* Incremented again right after the loop. */
+				tmpstr--;
+				break;
+			}
+			/* Skip delimiters */
+			while (ISDIRDELIM(*tmpstr)) tmpstr--;
+		}
+		tmpstr++;
+		if (*path == '\0') {
+			if (tmpstr == file_cwd) {
+				*tmpstr = '/';
+				tmpstr++;
+			}
+			*tmpstr = '\0';
+			return 0;
+		}
+		*tmpstr = '/';
+		pathcpy(tmpstr+1, path);
+	}
+
+	return 0;
+}
+
+int
+file_detectfs(void)
+{
+	int i;
+
+	current_filesystem = FSTYPE_NONE;
+
+	for (i = 0; i < NUM_FILESYS; i++) {
+		if (filesystems[i].detect() == 0) {
+			strcpy(file_cwd, "/");
+			current_filesystem = i;
+			break;
+		}
+	}
+
+	return current_filesystem;
+}
+
+int
+file_ls(const char *dir)
+{
+	char fullpath[1024];
+	const char *arg;
+
+	if (current_filesystem == FSTYPE_NONE) {
+		printf("Can't list files without a filesystem!\n");
+		return -1;
+	}
+
+	if (ISDIRDELIM(*dir)) {
+		arg = dir;
+	} else {
+		sprintf(fullpath, "%s/%s", file_cwd, dir);
+		arg = fullpath;
+	}
+	return filesystems[current_filesystem].ls(arg);
+}
+
+int file_read(const char *filename, void *buffer, int maxsize)
+{
+	char fullpath[1024];
+	const char *arg;
+
+	if (current_filesystem == FSTYPE_NONE) {
+		printf("Can't load file without a filesystem!\n");
+		return -1;
+	}
+
+	if (ISDIRDELIM(*filename)) {
+		arg = filename;
+	} else {
+		sprintf(fullpath, "%s/%s", file_cwd, filename);
+		arg = fullpath;
+	}
+
+	return filesystems[current_filesystem].read(arg, buffer, maxsize);
+}