bootstd: Add an implementation of distro boot

Add a bootmeth driver which handles distro boot from a disk, so we can
boot a bootflow using this commonly used mechanism.

In effect, this provides the same functionality as the 'sysboot' command
and shares the same code. But the interface into it is via a bootmeth.

For now this requires the 'pxe' command be enabled. Future work may tidy
this up so that it can be used without CONFIG_CMDLINE being enabled.

Signed-off-by: Simon Glass <sjg@chromium.org>

diff --git a/MAINTAINERS b/MAINTAINERS
index 5a48b8419909b70f7abb4ab31b6ca6a5fc22d424..d9125fca850df6824413cba6f2cddc3d162c61fe 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -701,7 +701,8 @@ F:  boot/bootflow.c
 F:     boot/bootmeth*.c
 F:     boot/bootstd.c
 F:     cmd/bootdev.c
-F:     include/bootdev*.h
+F:     cmd/bootflow.c
+F:     include/bootdev.h
 F:     include/bootflow.h
 F:     include/bootmeth.h
 F:     include/bootstd.h

diff --git a/boot/Kconfig b/boot/Kconfig
index 9faa55a5418c4538e8e744473001c68383958632..d34c31303dcbdc0b7723a649ca7003593e7e3344 100644 (file)
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -326,6 +326,21 @@ config BOOTSTD_FULL
          - support for selecting the ordering of bootdevs using the devicetree
            as well as the "boot_targets" environment variable
 
+if BOOTSTD
+
+config BOOTMETH_DISTRO
+       bool "Bootdev support for distro boot"
+       depends on CMD_PXE
+       default y
+       help
+         Enables support for distro boot using bootdevs. This makes the
+         bootdevs look for a 'extlinux/extlinux.conf' on each filesystem
+         they scan.
+
+         This provides a way to try out standard boot on an existing boot flow.
+
+endif
+
 config LEGACY_IMAGE_FORMAT
        bool "Enable support for the legacy image format"
        default y if !FIT_SIGNATURE

diff --git a/boot/Makefile b/boot/Makefile
index ac861fd035f07f1e7c378ff5afb465b87c307da4..6b7014b41acd40dcf1db84165a51af28e64904f1 100644 (file)
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -24,6 +24,8 @@ obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootflow.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootmeth-uclass.o
 obj-$(CONFIG_$(SPL_TPL_)BOOTSTD) += bootstd-uclass.o
 
+obj-$(CONFIG_$(SPL_TPL_)BOOTMETH_DISTRO) += bootmeth_distro.o
+
 obj-$(CONFIG_$(SPL_TPL_)OF_LIBFDT) += image-fdt.o
 obj-$(CONFIG_$(SPL_TPL_)FIT_SIGNATURE) += fdt_region.o
 obj-$(CONFIG_$(SPL_TPL_)FIT) += image-fit.o

diff --git a/boot/bootmeth_distro.c b/boot/bootmeth_distro.c
new file mode 100644 (file)
index 0000000..2b41e65
--- /dev/null
+++ b/boot/bootmeth_distro.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Bootmethod for distro boot (syslinux boot from a block device)
+ *
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#define LOG_CATEGORY UCLASS_BOOTSTD
+
+#include <common.h>
+#include <bootdev.h>
+#include <bootflow.h>
+#include <bootmeth.h>
+#include <bootstd.h>
+#include <command.h>
+#include <distro.h>
+#include <dm.h>
+#include <fs.h>
+#include <malloc.h>
+#include <mapmem.h>
+#include <mmc.h>
+#include <pxe_utils.h>
+
+static int disto_getfile(struct pxe_context *ctx, const char *file_path,
+                        char *file_addr, ulong *sizep)
+{
+       struct distro_info *info = ctx->userdata;
+       ulong addr;
+       int ret;
+
+       addr = simple_strtoul(file_addr, NULL, 16);
+
+       /* Allow up to 1GB */
+       *sizep = 1 << 30;
+       ret = bootmeth_read_file(info->dev, info->bflow, file_path, addr,
+                                sizep);
+       if (ret)
+               return log_msg_ret("read", ret);
+
+       return 0;
+}
+
+static int distro_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 distro_read_bootflow(struct udevice *dev, struct bootflow *bflow)
+{
+       struct blk_desc *desc;
+       const char *const *prefixes;
+       struct udevice *bootstd;
+       const char *prefix;
+       loff_t size;
+       int ret, i;
+
+       ret = uclass_first_device_err(UCLASS_BOOTSTD, &bootstd);
+       if (ret)
+               return log_msg_ret("std", ret);
+
+       /* If a block device, we require a partition table */
+       if (bflow->blk && !bflow->part)
+               return -ENOENT;
+
+       prefixes = bootstd_get_prefixes(bootstd);
+       i = 0;
+       desc = bflow->blk ? dev_get_uclass_plat(bflow->blk) : NULL;
+       do {
+               prefix = prefixes ? prefixes[i] : NULL;
+
+               ret = bootmeth_try_file(bflow, desc, prefix, DISTRO_FNAME);
+       } while (ret && prefixes && prefixes[++i]);
+       if (ret)
+               return log_msg_ret("try", ret);
+       size = bflow->size;
+
+       ret = bootmeth_alloc_file(bflow, 0x10000, 1);
+       if (ret)
+               return log_msg_ret("read", ret);
+
+       return 0;
+}
+
+static int distro_boot(struct udevice *dev, struct bootflow *bflow)
+{
+       struct cmd_tbl cmdtp = {};      /* dummy */
+       struct pxe_context ctx;
+       struct distro_info info;
+       ulong addr;
+       int ret;
+
+       addr = map_to_sysmem(bflow->buf);
+       info.dev = dev;
+       info.bflow = bflow;
+       ret = pxe_setup_ctx(&ctx, &cmdtp, disto_getfile, &info, true,
+                           bflow->subdir);
+       if (ret)
+               return log_msg_ret("ctx", -EINVAL);
+
+       ret = pxe_process(&ctx, addr, false);
+       if (ret)
+               return log_msg_ret("bread", -EINVAL);
+
+       return 0;
+}
+
+static int distro_bootmeth_bind(struct udevice *dev)
+{
+       struct bootmeth_uc_plat *plat = dev_get_uclass_plat(dev);
+
+       plat->desc = IS_ENABLED(CONFIG_BOOTSTD_FULL) ?
+               "Syslinux boot from a block device" : "syslinux";
+
+       return 0;
+}
+
+static struct bootmeth_ops distro_bootmeth_ops = {
+       .check          = distro_check,
+       .read_bootflow  = distro_read_bootflow,
+       .read_file      = bootmeth_common_read_file,
+       .boot           = distro_boot,
+};
+
+static const struct udevice_id distro_bootmeth_ids[] = {
+       { .compatible = "u-boot,distro-syslinux" },
+       { }
+};
+
+U_BOOT_DRIVER(bootmeth_distro) = {
+       .name           = "bootmeth_distro",
+       .id             = UCLASS_BOOTMETH,
+       .of_match       = distro_bootmeth_ids,
+       .ops            = &distro_bootmeth_ops,
+       .bind           = distro_bootmeth_bind,
+};

diff --git a/include/distro.h b/include/distro.h
new file mode 100644 (file)
index 0000000..2ee1458
--- /dev/null
+++ b/include/distro.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#ifndef __distro_h
+#define __distro_h
+
+#define DISTRO_FNAME   "extlinux/extlinux.conf"
+
+/**
+ * struct distro_info - useful information for distro_getfile()
+ *
+ * @dev: bootmethod device being used to boot
+ * @bflow: bootflow being booted
+ */
+struct distro_info {
+       struct udevice *dev;
+       struct bootflow *bflow;
+       struct cmd_tbl *cmdtp;
+};
+
+#endif