imx-common: add m4boot command

Add m4boot command which allows to boot FIT images on the Cortex-M4
kernel. The command currently only supports FIT image, which allows
to provide entry point and load addresses for all boot artifacts.

Currently, the Cortex-M4 mini loader needs to be loaded manually
to Kernel loadaddr - 0x80 (e.g. 0x8f000000, if kernel is loaded at
0x8f000080).

3 files changed, 198 insertions, 0 deletions

diff --git a/arch/arm/imx-common/Makefile b/arch/arm/imx-common/Makefile
index 62ae6d64b8..175a36339d 100644
--- a/arch/arm/imx-common/Makefile
+++ b/arch/arm/imx-common/Makefile
@@ -28,6 +28,7 @@ endif
 obj-$(CONFIG_CMD_BMODE) += cmd_bmode.o
 obj-$(CONFIG_CMD_HDMIDETECT) += cmd_hdmidet.o
 obj-$(CONFIG_CMD_DEKBLOB) += cmd_dek.o
+obj-$(CONFIG_CMD_M4BOOT) += cmd_m4boot.o
 obj-$(CONFIG_CMD_WRITEBCB) += cmd_writebcb.o
 
 quiet_cmd_cpp_cfg = CFGS    $@
diff --git a/arch/arm/imx-common/cmd_m4boot.c b/arch/arm/imx-common/cmd_m4boot.c
new file mode 100644
index 0000000000..67c4c4fa07
--- /dev/null
+++ b/arch/arm/imx-common/cmd_m4boot.c
@@ -0,0 +1,193 @@
+/*
+ * Copyright (c) 2015, Stefan Agner.  All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <bootm.h>
+#include <command.h>
+#include <malloc.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/arch/crm_regs.h>
+#include <asm/io.h>
+#include <image.h>
+
+#ifndef CONFIG_SYS_FDT_PAD
+#define CONFIG_SYS_FDT_PAD 0x3000
+#endif
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#define CCM_CCOWR_START 0x00015a5a
+
+static void boot_startm4_linux(bootm_headers_t *images)
+{
+	struct src *src = (struct src *)SRC_BASE_ADDR;
+	struct ccm_reg *ccm = (struct ccm_reg *)CCM_BASE_ADDR;
+	ulong ep_loader = images->ep - 0x80;
+
+	printf("Booting Cortex-M4 @0x%08lx\n", ep_loader);
+
+	/* Write entry point to GPR2 (PERSISTENT_ENTRY1) */
+	writel(ep_loader, &src->gpr2);
+
+	/* Write fdt offset to GPR3 (PERSISTENT_ARG1) */
+	writel((ulong)images->ft_addr, &src->gpr3);
+
+	flush_dcache_all();
+
+	/* Gate Cortex-M4 clock... */
+	writel(CCM_CCOWR_START, &ccm->ccowr);
+}
+
+static int fdt_chosenm4(void *fdt)
+{
+	int   nodeoffset;
+	int   err;
+	char  *str;		/* used to set string properties */
+
+	err = fdt_check_header(fdt);
+	if (err < 0) {
+		printf("fdt_chosen: %s\n", fdt_strerror(err));
+		return err;
+	}
+
+	/* find or create "/chosen" node. */
+	nodeoffset = fdt_find_or_add_subnode(fdt, 0, "chosen");
+	if (nodeoffset < 0)
+		return nodeoffset;
+
+	str = getenv("bootargsm4");
+	if (str) {
+		err = fdt_setprop(fdt, nodeoffset, "bootargs", str,
+				  strlen(str) + 1);
+		if (err < 0) {
+			printf("WARNING: could not set bootargs %s.\n",
+			       fdt_strerror(err));
+			return err;
+		}
+	}
+
+	return 0;
+}
+
+static int do_m4boot(cmd_tbl_t *cmdtp, int flag, int argc,
+		       char * const argv[])
+{
+	int ret;
+	bootm_headers_t images;
+	ulong img_addr, initrd_len;
+
+	memset(&images, '\0', sizeof(images));
+
+	/* Consume 'm4boot' */
+	argc--; argv++;
+
+	/*
+	 * We support FIT images only, call directly into FIT image functions
+	 */
+	bootm_disable_interrupts();
+	lmb_init(&images.lmb);
+
+	/*
+	 * Parse provided address - default to load_addr in case not provided -
+	 * and store config name as string in fit_uname_cfg (e.g. config@1)
+	 */
+	fit_parse_conf(argc < 1 ? NULL : argv[0], load_addr, &img_addr,
+		       &images.fit_uname_cfg);
+
+
+	/*
+	 * Load OS image...
+	 */
+	ret = fit_image_load(&images, img_addr, &images.fit_uname_os,
+			     &images.fit_uname_cfg, IH_ARCH_ARM,
+			     IH_TYPE_KERNEL, BOOTSTAGE_ID_FIT_KERNEL_START,
+			     FIT_LOAD_OPTIONAL_NON_ZERO,
+			     &images.os.image_start, &images.os.image_len);
+
+	if (ret < 0) {
+		puts("ERROR: can't get kernel image!\n");
+		return 1;
+	}
+
+	images.fit_noffset_os = ret;
+	images.fit_hdr_os = map_sysmem(img_addr, 0);
+	fit_image_get_entry(images.fit_hdr_os, images.fit_noffset_os,
+			    &images.ep);
+	fit_image_get_os(images.fit_hdr_os, images.fit_noffset_os,
+			 &images.os.os);
+
+
+	ret = fit_image_load(&images, img_addr, &images.fit_uname_rd,
+			     &images.fit_uname_cfg, IH_ARCH_ARM,
+			     IH_TYPE_RAMDISK, BOOTSTAGE_ID_FIT_RD_START,
+			     FIT_LOAD_OPTIONAL_NON_ZERO,
+			     &images.initrd_start, &initrd_len);
+
+	if (ret) {
+		images.fit_noffset_rd = ret;
+		images.initrd_end = images.initrd_start + initrd_len;
+	}
+
+	ret = fit_image_load(&images, img_addr, &images.fit_uname_fdt,
+			     &images.fit_uname_cfg, IH_ARCH_ARM,
+			     IH_TYPE_FLATDT, BOOTSTAGE_ID_FIT_FDT_START,
+			     FIT_LOAD_OPTIONAL_NON_ZERO,
+			     (ulong *)&images.ft_addr, &images.ft_len);
+
+	if (ret > 0) {
+		images.fit_noffset_fdt = ret;
+		/*
+		 * We assume there is space after the existing fdt to use
+		 * for padding
+		 */
+		images.ft_len += CONFIG_SYS_FDT_PAD;
+		lmb_reserve(&images.lmb, (ulong)images.ft_addr, images.ft_len);
+		fdt_set_totalsize(images.ft_addr, images.ft_len);
+		printf("   Using Device Tree in place at %p, end %p\n",
+			images.ft_addr, images.ft_addr + images.ft_len - 1);
+
+		set_working_fdt_addr((ulong)images.ft_addr);
+
+		/*
+		 * We could use image_setup_libfdt here, however that function
+		 * goes through the whole arch/board/system fdt setup, which is
+		 * not what we want for Cortex-M4
+		 *
+		 * Fixup some properties directly...
+		 */
+		ret = fdt_chosenm4(images.ft_addr);
+		if (ret < 0)
+			return ret;
+
+		ret = fdt_initrd(images.ft_addr, images.initrd_start,
+				 images.initrd_end);
+		if (ret < 0)
+			return ret;
+	} else if (images.os.os == IH_OS_LINUX) {
+		/* Linux on Cortex-M4 needs a valid device tree... */
+		puts("Could not find a valid device tree\n");
+		return 1;
+	}
+
+	/* Verify entry point is a Thumb2 address */
+	if (!(images.ep & 0x1)) {
+		printf("Entry point 0x%08lx is not a valid Thumb2 address\n",
+			images.ep);
+		return 0;
+	}
+
+	boot_startm4_linux(&images);
+
+	return 1;
+}
+
+U_BOOT_CMD(
+	m4boot, CONFIG_SYS_MAXARGS, 1, do_m4boot,
+	"boot Linux on secondary Cortex-M4 core using FIT image from memory",
+	"[<addr>[#<conf>]]\n"
+	"    - boot Linux on secondary Cortex-M4 core using FIT image\n"
+	"The argument needs to be a valid FIT image\n"
+);
diff --git a/include/configs/colibri_vf.h b/include/configs/colibri_vf.h
index 8d10aa47e5..db0593988d 100644
--- a/include/configs/colibri_vf.h
+++ b/include/configs/colibri_vf.h
@@ -270,6 +270,10 @@
 #define CONFIG_SUPPORT_RAW_INITRD
 #define CONFIG_SYS_BOOT_RAMDISK_HIGH
 
+#define CONFIG_CMD_M4BOOT
+#define CONFIG_CMD_CACHE
+#define CONFIG_FIT
+
 #define CONFIG_SYS_NO_FLASH
 
 #define CONFIG_SYS_CACHELINE_SIZE 32