uboot: HTTP netboot support

If we receive an option 67 (bootfile) matching http://IP/rootfs.itb,
use U-Boot's wget implementation to download the file. The web server
must listen on port 80. tftp:// is also supported.

Without a protocol prefix, assume that the bootfile should be fetched
using TFTP from ${serverip}.

board/common/uboot/extras.config

@@ -26,6 +26,10 @@ CONFIG_CMD_MMC=y
 CONFIG_FS_SQUASHFS=y
 CONFIG_CMD_SQUASHFS=y
 
+CONFIG_PROT_TCP=y
+CONFIG_PROT_TCP_SACK=y
+CONFIG_CMD_WGET=y
+
 CONFIG_USE_PREBOOT=y
 CONFIG_CMD_BOOTMENU=y
 CONFIG_CMD_PAUSE=y

board/common/uboot/scripts/ixprepdhcp.sh

@@ -1,16 +1,28 @@
-if dhcp ${ramdisk_addr_r}; then
+setenv autoload no
 
-    setenv old_fdt_addr ${fdt_addr}
-    if fdt addr ${ramdisk_addr_r}; then
-	fdt get value sqoffs /images/rootfs data-position
-	fdt get value sqsize /images/rootfs data-size
-	fdt addr ${old_fdt_addr}
+if dhcp; then
+    setenv proto tftp
+    setenv dltool tftpboot
 
-	setexpr sqaddr    ${ramdisk_addr_r} + ${sqoffs}
-	setexpr sqblkcnt  ${sqsize} / 0x200
-	setexpr sqkbsize  ${sqsize} / 0x400
+    if setexpr proto sub "^(http|tftp)://.*" "\\1" "${bootfile}" && setexpr bootfile sub "^(http|tftp)://([^/]+?)/(.*)" "\2:\3"; then
+	if test "${proto}" = "http"; then
+	    setenv dltool wget
+	fi
+    fi
 
-	setenv bootargs_root "root=/dev/ram0 ramdisk_size=0x${sqkbsize} initrd=0x${sqaddr},${sqsize}"
-	setenv prepared ok
+    if ${dltool} ${ramdisk_addr_r} "${bootfile}"; then
+	setenv old_fdt_addr ${fdt_addr}
+	if fdt addr ${ramdisk_addr_r}; then
+	    fdt get value sqoffs /images/rootfs data-position
+	    fdt get value sqsize /images/rootfs data-size
+	    fdt addr ${old_fdt_addr}
+
+	    setexpr sqaddr    ${ramdisk_addr_r} + ${sqoffs}
+	    setexpr sqblkcnt  ${sqsize} / 0x200
+	    setexpr sqkbsize  ${sqsize} / 0x400
+
+	    setenv bootargs_root "root=/dev/ram0 ramdisk_size=0x${sqkbsize} initrd=0x${sqaddr},${sqsize}"
+	    setenv prepared ok
+	fi
     fi
 fi