bootstd: ethernet: Add a bootdev driver

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>

diff --git a/MAINTAINERS b/MAINTAINERS
index 239fa2e..77a3408 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -707,6 +707,7 @@ 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 ef0aa16..964a4fe 100644 (file)
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -25,6 +25,15 @@ 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 fb3eba8..6c81250 100644 (file)
--- 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 58c308f..bcefc54 100644 (file)
--- 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 (file)
index 0000000..b735966
--- /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,
+};