bootstd: Add an implementation of script boot
Add a bootmeth driver which handles distro boot from a disk via a U-Boot
script, so we can boot a bootflow using this commonly used mechanism. This
is required by Armbian, for example.
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/Kconfig b/boot/Kconfig
index 373871c..64e16f3 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -377,6 +377,17 @@
This is a sandbox bootmeth driver used for testing. It always returns
-ENOTSUPP when attempting to boot.
+config BOOTMETH_SCRIPT
+ bool "Bootdev support for U-Boot scripts"
+ default y if BOOTSTD_FULL
+ help
+ Enables support for booting a distro via a U-Boot script. This makes
+ the bootdevs look for a 'boot/boot.scr' file which can be used to
+ boot the distro.
+
+ This provides a way to try out standard boot on an existing boot flow.
+ It is not enabled by default to save space.
+
endif
config LEGACY_IMAGE_FORMAT
diff --git a/boot/Makefile b/boot/Makefile
index 444e697..a706742 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -28,6 +28,7 @@
obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_DISTRO_PXE) += bootmeth_pxe.o
obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_EFILOADER) += bootmeth_efi.o
obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_SANDBOX) += bootmeth_sandbox.o
+obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_SCRIPT) += bootmeth_script.o
ifdef CONFIG_$(SPL_TPL_)BOOTSTD_FULL
obj-$(CONFIG_$(SPL_TPL_)CMD_BOOTEFI_BOOTMGR) += bootmeth_efi_mgr.o
endif
diff --git a/boot/bootmeth_script.c b/boot/bootmeth_script.c
new file mode 100644
index 0000000..d1c3f94
--- /dev/null
+++ b/boot/bootmeth_script.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Bootmethod for booting via a U-Boot script
+ *
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <common.h>
+#include <blk.h>
+#include <bootflow.h>
+#include <bootmeth.h>
+#include <bootstd.h>
+#include <dm.h>
+#include <env.h>
+#include <fs.h>
+#include <image.h>
+#include <malloc.h>
+#include <mapmem.h>
+
+#define SCRIPT_FNAME1 "boot.scr.uimg"
+#define SCRIPT_FNAME2 "boot.scr"
+
+static int script_check(struct udevice *dev, struct bootflow_iter *iter)
+{
+ int ret;
+
+ /* This only works on block devices */
+ ret = bootflow_iter_uses_blk_dev(iter);
+ if (ret)
+ return log_msg_ret("blk", ret);
+
+ return 0;
+}
+
+static int script_read_bootflow(struct udevice *dev, struct bootflow *bflow)
+{
+ struct blk_desc *desc = NULL;
+ const char *const *prefixes;
+ struct udevice *bootstd;
+ const char *prefix;
+ int ret, i;
+
+ ret = uclass_first_device_err(UCLASS_BOOTSTD, &bootstd);
+ if (ret)
+ return log_msg_ret("std", ret);
+
+ /* We require a partition table */
+ if (!bflow->part)
+ return -ENOENT;
+
+ if (bflow->blk)
+ desc = dev_get_uclass_plat(bflow->blk);
+
+ prefixes = bootstd_get_prefixes(bootstd);
+ i = 0;
+ do {
+ prefix = prefixes ? prefixes[i] : NULL;
+
+ ret = bootmeth_try_file(bflow, desc, prefix, SCRIPT_FNAME1);
+ if (ret)
+ ret = bootmeth_try_file(bflow, desc, prefix,
+ SCRIPT_FNAME2);
+ } while (ret && prefixes && prefixes[++i]);
+ if (ret)
+ return log_msg_ret("try", ret);
+
+ bflow->subdir = strdup(prefix ? prefix : "");
+ if (!bflow->subdir)
+ return log_msg_ret("prefix", -ENOMEM);
+
+ ret = bootmeth_alloc_file(bflow, 0x10000, 1);
+ if (ret)
+ return log_msg_ret("read", ret);
+
+ return 0;
+}
+
+static int script_boot(struct udevice *dev, struct bootflow *bflow)
+{
+ struct blk_desc *desc = dev_get_uclass_plat(bflow->blk);
+ ulong addr;
+ int ret;
+
+ ret = env_set("devtype", blk_get_devtype(bflow->blk));
+ if (!ret)
+ ret = env_set_hex("devnum", desc->devnum);
+ if (!ret)
+ ret = env_set("prefix", bflow->subdir);
+ if (!ret && IS_ENABLED(CONFIG_ARCH_SUNXI) &&
+ !strcmp("mmc", blk_get_devtype(bflow->blk)))
+ ret = env_set_hex("mmc_bootdev", desc->devnum);
+ if (ret)
+ return log_msg_ret("env", ret);
+
+ log_debug("devtype: %s\n", env_get("devtype"));
+ log_debug("devnum: %s\n", env_get("devnum"));
+ log_debug("prefix: %s\n", env_get("prefix"));
+ log_debug("mmc_bootdev: %s\n", env_get("mmc_bootdev"));
+
+ addr = map_to_sysmem(bflow->buf);
+ ret = image_source_script(addr, NULL);
+ if (ret)
+ return log_msg_ret("boot", ret);
+
+ return 0;
+}
+
+static int script_bootmeth_bind(struct udevice *dev)
+{
+ struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
+
+ plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
+ "Script boot from a block device" : "script";
+
+ return 0;
+}
+
+static struct bootmeth_ops script_bootmeth_ops = {
+ .check = script_check,
+ .read_bootflow = script_read_bootflow,
+ .read_file = bootmeth_common_read_file,
+ .boot = script_boot,
+};
+
+static const struct udevice_id script_bootmeth_ids[] = {
+ { .compatible = "u-boot,script" },
+ { }
+};
+
+U_BOOT_DRIVER(bootmeth_script) = {
+ .name = "bootmeth_script",
+ .id = UCLASS_BOOTMETH,
+ .of_match = script_bootmeth_ids,
+ .ops = &script_bootmeth_ops,
+ .bind = script_bootmeth_bind,
+};