定义 dhcp命令
#if defined(CONFIG_CMD_DHCP)
static int do_dhcp(struct cmd_tbl *cmdtp, int flag, int argc,char *const argv[])
{return netboot_common(DHCP, cmdtp, argc, argv);
}U_BOOT_CMD(dhcp, 3, 1, do_dhcp,"boot image via network using DHCP/TFTP protocol","[loadAddress] [[hostIPaddr:]bootfilename]"
);
#endif
netboot_common
u-boot/cmd/net.cstatic int netboot_common(enum proto_t proto, struct cmd_tbl *cmdtp, int argc,
194 char *const argv[])
195{
196 char *s;
197 char *end;
198 int rcode = 0;
199 int size;
200 ulong addr;
201
202 net_boot_file_name_explicit = false;
203
204 /* pre-set image_load_addr */
205 s = env_get("loadaddr");
206 if (s != NULL)
207 image_load_addr = simple_strtoul(s, NULL, 16);
208
209 switch (argc) {
210 case 1:
211 /* refresh bootfile name from env */
212 copy_filename(net_boot_file_name, env_get(&#
