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/arch/sparc/lib/bootm.c

@@ -0,0 +1,166 @@
+/* SPARC code for booting linux 2.6
+ *
+ * (C) Copyright 2007
+ * Daniel Hellstrom, Gaisler Research, daniel@gaisler.com.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <command.h>
+#include <asm/byteorder.h>
+#include <asm/prom.h>
+#include <asm/cache.h>
+#include <image.h>
+
+#define PRINT_KERNEL_HEADER
+
+extern image_header_t header;
+extern void srmmu_init_cpu(unsigned int entry);
+extern void prepare_bootargs(char *bootargs);
+
+/* sparc kernel argument (the ROM vector) */
+struct linux_romvec *kernel_arg_promvec;
+
+/* page szie is 4k */
+#define PAGE_SIZE 0x1000
+#define RAMDISK_IMAGE_START_MASK	0x07FF
+#define RAMDISK_PROMPT_FLAG		0x8000
+#define RAMDISK_LOAD_FLAG		0x4000
+struct __attribute__ ((packed)) {
+	char traptable[PAGE_SIZE];
+	char swapper_pg_dir[PAGE_SIZE];
+	char pg0[PAGE_SIZE];
+	char pg1[PAGE_SIZE];
+	char pg2[PAGE_SIZE];
+	char pg3[PAGE_SIZE];
+	char empty_bad_page[PAGE_SIZE];
+	char empty_bad_page_table[PAGE_SIZE];
+	char empty_zero_page[PAGE_SIZE];
+	unsigned char hdr[4];	/* ascii "HdrS" */
+	/* 00.02.06.0b is for Linux kernel 2.6.11 */
+	unsigned char linuxver_mega_major;
+	unsigned char linuxver_major;
+	unsigned char linuxver_minor;
+	unsigned char linuxver_revision;
+	/* header version 0x0203 */
+	unsigned short hdr_ver;
+	union __attribute__ ((packed)) {
+		struct __attribute__ ((packed)) {
+			unsigned short root_flags;
+			unsigned short root_dev;
+			unsigned short ram_flags;
+			unsigned int sparc_ramdisk_image;
+			unsigned int sparc_ramdisk_size;
+			unsigned int reboot_command;
+			unsigned int resv[3];
+			unsigned int end;
+		} ver_0203;
+	} hdr_input;
+} *linux_hdr;
+
+/* temporary initrd image holder */
+image_header_t ihdr;
+
+void arch_lmb_reserve(struct lmb *lmb)
+{
+	/* Reserve the space used by PROM and stack. This is done
+	 * to avoid that the RAM image is copied over stack or
+	 * PROM.
+	 */
+	lmb_reserve(lmb, CONFIG_SYS_RELOC_MONITOR_BASE, CONFIG_SYS_RAM_END);
+}
+
+/* boot the linux kernel */
+int do_bootm_linux(int flag, int argc, char * const argv[], bootm_headers_t * images)
+{
+	char *bootargs;
+	ulong rd_len;
+	void (*kernel) (struct linux_romvec *, void *);
+	int ret;
+
+	/*
+	 * allow the PREP bootm subcommand, it is required for bootm to work
+	 */
+	if (flag & BOOTM_STATE_OS_PREP)
+		return 0;
+
+	if ((flag != 0) && (flag != BOOTM_STATE_OS_GO))
+		return 1;
+
+	/* Get virtual address of kernel start */
+	linux_hdr = (void *)images->os.load;
+
+	/* */
+	kernel = (void (*)(struct linux_romvec *, void *))images->ep;
+
+	/* check for a SPARC kernel */
+	if ((linux_hdr->hdr[0] != 'H') ||
+	    (linux_hdr->hdr[1] != 'd') ||
+	    (linux_hdr->hdr[2] != 'r') || (linux_hdr->hdr[3] != 'S')) {
+		puts("Error reading header of SPARC Linux kernel, aborting\n");
+		goto error;
+	}
+#ifdef PRINT_KERNEL_HEADER
+	printf("## Found SPARC Linux kernel %d.%d.%d ...\n",
+	       linux_hdr->linuxver_major,
+	       linux_hdr->linuxver_minor, linux_hdr->linuxver_revision);
+#endif
+
+	/* set basic boot params in kernel header now that it has been
+	 * extracted and is writeable.
+	 */
+
+	ret = image_setup_linux(images);
+	if (ret) {
+		puts("### Failed to relocate RAM disk\n");
+		goto error;
+	}
+
+	/* Calc length of RAM disk, if zero no ramdisk available */
+	rd_len = images->rd_end - images->rd_start;
+
+	if (rd_len) {
+		/* Update SPARC kernel header so that Linux knows
+		 * what is going on and where to find RAM disk.
+		 *
+		 * Set INITRD Image address relative to RAM Start
+		 */
+		linux_hdr->hdr_input.ver_0203.sparc_ramdisk_image =
+			images->initrd_start - CONFIG_SYS_RAM_BASE;
+		linux_hdr->hdr_input.ver_0203.sparc_ramdisk_size = rd_len;
+		/* Clear READ ONLY flag if set to non-zero */
+		linux_hdr->hdr_input.ver_0203.root_flags = 1;
+		/* Set root device to: Root_RAM0 */
+		linux_hdr->hdr_input.ver_0203.root_dev = 0x100;
+		linux_hdr->hdr_input.ver_0203.ram_flags = 0;
+	} else {
+		/* NOT using RAMDISK image, overwriting kernel defaults */
+		linux_hdr->hdr_input.ver_0203.sparc_ramdisk_image = 0;
+		linux_hdr->hdr_input.ver_0203.sparc_ramdisk_size = 0;
+		/* Leave to kernel defaults
+		   linux_hdr->hdr_input.ver_0203.root_flags = 1;
+		   linux_hdr->hdr_input.ver_0203.root_dev = 0;
+		   linux_hdr->hdr_input.ver_0203.ram_flags = 0;
+		 */
+	}
+
+	/* Copy bootargs from bootargs variable to kernel readable area */
+	bootargs = getenv("bootargs");
+	prepare_bootargs(bootargs);
+
+	/* turn on mmu & setup context table & page table for process 0 (kernel) */
+	srmmu_init_cpu((unsigned int)kernel);
+
+	/* Enter SPARC Linux kernel
+	 * From now on the only code in u-boot that will be
+	 * executed is the PROM code.
+	 */
+	kernel(kernel_arg_promvec, (void *)images->ep);
+
+	/* It will never come to this... */
+	while (1) ;
+
+      error:
+	return 1;
+}