[PATCH v4 22/33] bootstd: ethernet: Add a bootdev driver

Simon Glass
2022-03-06T12:54:14Z

Add a bootdev driver for Ethernet. It can use the PXE boot mechanism to
locate a file, added later.

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

(no changes since v1)

MAINTAINERS | 1 +
net/Kconfig | 9 +++++
net/Makefile | 1 +
net/eth-uclass.c | 8 ++++
net/eth_bootdev.c | 101 ++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 120 insertions(+)
create mode 100644 net/eth_bootdev.c

diff --git a/MAINTAINERS b/MAINTAINERS
index f4bbaeaf11..e90c43dd61 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -696,6 +696,7 @@ F: include/bootdev.h
F: include/bootflow.h
F: include/bootmeth.h
F: include/bootstd.h
+F: net/eth_bootdevice.c

BTRFS
M: Marek Behun <marek.behun@nic.cz>
diff --git a/net/Kconfig b/net/Kconfig
index 2ae9d6a020..41156977f9 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -14,6 +14,15 @@ config PROT_UDP
Enable a generic udp framework that allows defining a custom
handler for udp protocol.

+config BOOTDEV_ETH
+ bool "Enable bootdev for ethernet"
+ depends on BOOTSTD
+ default y
+ help
+ Provide a bootdev for ethernet so that is it possible to boot
+ an operationg system over the network, using the PXE (Preboot
+ Execution Environment) protocol.
+
config BOOTP_SEND_HOSTNAME
bool "Send hostname to DNS server"
help
diff --git a/net/Makefile b/net/Makefile
index fb3eba840f..6c812502d3 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_CMD_DNS) += dns.o
obj-$(CONFIG_DM_DSA) += dsa-uclass.o
ifdef CONFIG_DM_ETH
obj-$(CONFIG_NET) += eth-uclass.o
+obj-$(CONFIG_$(SPL_TPL_)BOOTDEV_ETH) += eth_bootdev.o
else
obj-$(CONFIG_NET) += eth_legacy.o
endif
diff --git a/net/eth-uclass.c b/net/eth-uclass.c
index 58c308f332..bcefc54ded 100644
--- a/net/eth-uclass.c
+++ b/net/eth-uclass.c
@@ -8,6 +8,7 @@
#define LOG_CATEGORY UCLASS_ETH

#include <common.h>
+#include <bootdev.h>
#include <bootstage.h>
#include <dm.h>
#include <env.h>
@@ -473,6 +474,8 @@ int eth_initialize(void)

static int eth_post_bind(struct udevice *dev)
{
+ int ret;
+
if (strchr(dev->name, ' ')) {
printf("\nError: eth device name \"%s\" has a space!\n",
dev->name);
@@ -482,6 +485,11 @@ static int eth_post_bind(struct udevice *dev)
#ifdef CONFIG_DM_ETH_PHY
eth_phy_binds_nodes(dev);
#endif
+ if (CONFIG_IS_ENABLED(BOOTDEV_ETH)) {
+ ret = bootdev_setup_for_dev(dev, "eth_bootdev");
+ if (ret)
+ return log_msg_ret("bootdev", ret);
+ }

return 0;
}
diff --git a/net/eth_bootdev.c b/net/eth_bootdev.c
new file mode 100644
index 0000000000..b735966d2b
--- /dev/null
+++ b/net/eth_bootdev.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Bootdevice for ethernet (uses PXE)
+ *
+ * Copyright 2021 Google LLC
+ * Written by Simon Glass <sjg@chromium.org>
+ */
+
+#include <common.h>
+#include <bootdev.h>
+#include <bootflow.h>
+#include <command.h>
+#include <bootmeth.h>
+#include <distro.h>
+#include <dm.h>
+#include <log.h>
+#include <net.h>
+
+static int eth_get_bootflow(struct udevice *dev, struct bootflow_iter *iter,
+ struct bootflow *bflow)
+{
+ char name[60];
+ int ret;
+
+ /* Must be an Ethernet device */
+ ret = bootflow_iter_uses_network(iter);
+ if (ret)
+ return log_msg_ret("net", ret);
+
+ ret = bootmeth_check(bflow->method, iter);
+ if (ret)
+ return log_msg_ret("check", ret);
+
+ /*
+ * Like distro boot, this assumes there is only one Ethernet device.
+ * In this case, that means that @eth is ignored
+ */
+
+ snprintf(name, sizeof(name), "%s.%d", dev->name, iter->part);
+ bflow->name = strdup(name);
+ if (!bflow->name)
+ return log_msg_ret("name", -ENOMEM);
+
+ /*
+ * There is not a direct interface to the network stack so run
+ * everything through the command-line interpreter for now.
+ *
+ * Don't bother checking the result of dhcp. It can fail with:
+ *
+ * DHCP client bound to address 192.168.4.50 (4 ms)
+ * *** Warning: no boot file name; using 'C0A80432.img'
+ * Using smsc95xx_eth device
+ * TFTP from server 192.168.4.1; our IP address is 192.168.4.50
+ * Filename 'C0A80432.img'.
+ * Load address: 0x200000
+ * Loading: *
+ * TFTP error: 'File not found' (1)
+ *
+ * This is not a real failure, since we don't actually care if the
+ * boot file exists.
+ */
+ log_debug("running dhcp\n");
+ run_command("dhcp", 0);
+ bflow->state = BOOTFLOWST_MEDIA;
+
+ /* See distro_pxe_read_bootflow() for the standard impl of this */
+ log_debug("dhcp complete - reading bootflow with method %s\n",
+ bflow->method->name);
+ ret = bootmeth_read_bootflow(bflow->method, bflow);
+ log_debug("reading bootflow returned %d\n", ret);
+ if (ret)
+ return log_msg_ret("method", ret);
+
+ return 0;
+}
+
+static int eth_bootdev_bind(struct udevice *dev)
+{
+ struct bootdev_uc_plat *ucp = dev_get_uclass_plat(dev);
+
+ ucp->prio = BOOTDEVP_4_NET_BASE;
+
+ return 0;
+}
+
+struct bootdev_ops eth_bootdev_ops = {
+ .get_bootflow = eth_get_bootflow,
+};
+
+static const struct udevice_id eth_bootdev_ids[] = {
+ { .compatible = "u-boot,bootdev-eth" },
+ { }
+};
+
+U_BOOT_DRIVER(eth_bootdev) = {
+ .name = "eth_bootdev",
+ .id = UCLASS_BOOTDEV,
+ .ops = &eth_bootdev_ops,
+ .bind = eth_bootdev_bind,
+ .of_match = eth_bootdev_ids,
+};
--
2.35.1.616.g0bdcbb4464-goog