[PATCH v3 18/31] bootstd: Add an implementation of distro boot
Simon Glass
sjg at chromium.org
Wed Jan 19 02:43:02 CET 2022
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 at chromium.org>
---
Changes in v3:
- Use new bootmeth_try_file() function
- Use a short name when BOOTSTD_FULL is not enabled
- Use common bootmeth functions
MAINTAINERS | 3 +-
boot/Kconfig | 15 +++++
boot/Makefile | 2 +
boot/bootmeth_distro.c | 142 +++++++++++++++++++++++++++++++++++++++++
include/distro.h | 24 +++++++
5 files changed, 185 insertions(+), 1 deletion(-)
create mode 100644 boot/bootmeth_distro.c
create mode 100644 include/distro.h
diff --git a/MAINTAINERS b/MAINTAINERS
index ea8f8fdec91..e907151276a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -668,7 +668,8 @@ 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 032f0b93c68..45d38a226cb 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -315,6 +315,21 @@ 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 f58c192ae07..d8f5c340b85 100644
--- a/boot/Makefile
+++ b/boot/Makefile
@@ -28,6 +28,8 @@ 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
index 00000000000..7960b70979b
--- /dev/null
+++ b/boot/bootmeth_distro.c
@@ -0,0 +1,142 @@
+// 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 at 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 = dev_get_uclass_plat(bflow->blk);
+ 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);
+
+ /* We require a partition table */
+ if (!bflow->part)
+ return -ENOENT;
+
+ prefixes = bootstd_get_prefixes(bootstd);
+ i = 0;
+ 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
index 00000000000..2ee145871b2
--- /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 at 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
--
2.34.1.703.g22d0c6ccf7-goog
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