board: Enable ethernet, tftpboot support to pic32mzdask board.

This adds ethernet, TFTP support for PIC32MZ[DA] Starter Kit. Also
custom environment variables/scripts are added to help boot from network.

Signed-off-by: Purna Chandra Mandal <purna.mandal@microchip.com>

arch/mips/dts/pic32mzda.dtsi

@@ -161,4 +161,14 @@
 		bus-width = <4>;
 		status = "disabled";
 	};
+
+	ethernet: ethernet@1f882000 {
+		compatible = "microchip,pic32mzda-eth";
+		reg = <0x1f882000 0x1000>;
+		interrupts = <153 IRQ_TYPE_LEVEL_HIGH>;
+		clocks = <&clock PB5CLK>;
+		status = "disabled";
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
 };

arch/mips/dts/pic32mzda_sk.dts

@@ -42,4 +42,14 @@
 
 &sdhci {
 	status = "okay";
+};
+
+&ethernet {
+	reset-gpios = <&gpioJ 15 0>;
+	status = "okay";
+	phy-mode = "rmii";
+	phy-handle = <&ethernet_phy>;
+	ethernet_phy: lan8740_phy@0 {
+		reg = <0>;
+	};
 };

configs/pic32mzdask_defconfig

@@ -16,16 +16,19 @@ CONFIG_CMD_MEMINFO=y
 # CONFIG_CMD_FLASH is not set
 # CONFIG_CMD_FPGA is not set
 CONFIG_CMD_GPIO=y
-# CONFIG_CMD_NET is not set
-# CONFIG_CMD_NFS is not set
+CONFIG_CMD_RARP=y
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_PING=y
 CONFIG_CMD_TIME=y
 CONFIG_OF_EMBED=y
+CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_CLK=y
 CONFIG_DM_MMC=y
 CONFIG_PIC32_SDHCI=y
+CONFIG_DM_ETH=y
+CONFIG_PIC32_ETH=y
 CONFIG_PINCTRL=y
 # CONFIG_PINCTRL_FULL is not set
 CONFIG_SYS_VSNPRINTF=y
 CONFIG_USE_TINY_PRINTF=y
-CONFIG_REGEX=y
 CONFIG_CMD_DHRYSTONE=y

include/configs/pic32mzdask.h

@@ -73,6 +73,25 @@
 		(CONFIG_SYS_CBSIZE + sizeof(CONFIG_SYS_PROMPT) + 16)
 #define CONFIG_CMDLINE_EDITING		1
 
+/*-----------------------------------------------------------------------
+ * Networking Configuration
+ */
+#define CONFIG_MII
+#define CONFIG_PHY_SMSC
+#define CONFIG_SYS_RX_ETH_BUFFER	8
+#define CONFIG_NET_RETRY_COUNT		20
+#define CONFIG_ARP_TIMEOUT		500 /* millisec */
+
+#define CONFIG_CMD_MII
+
+/*
+ * BOOTP options
+ */
+#define CONFIG_BOOTP_BOOTFILESIZE
+#define CONFIG_BOOTP_BOOTPATH
+#define CONFIG_BOOTP_GATEWAY
+#define CONFIG_BOOTP_HOSTNAME
+
 /*
  * Handover flattened device tree (dtb file) to Linux kernel
  */
@@ -133,7 +152,8 @@
 		"fi; \0"
 
 #define BOOT_TARGET_DEVICES(func)	\
-	func(MMC, mmc, 0)
+	func(MMC, mmc, 0)		\
+	func(DHCP, dhcp, na)
 
 #include <config_distro_bootcmd.h>