Use an Ipv4AddrConfig enum instead of the USE_DHCP constant

artiq/firmware/bootloader/main.rs

@@ -19,7 +19,7 @@ use board_misoc::{clock, ethmac, net_settings};
 use board_misoc::uart_console::Console;
 use riscv::register::{mcause, mepc, mtval};
 use smoltcp::iface::SocketStorage;
-use smoltcp::wire::HardwareAddress;
+use smoltcp::wire::{HardwareAddress, IpAddress, Ipv4Address};
 
 fn check_integrity() -> bool {
     extern {
@@ -410,10 +410,13 @@ fn network_boot() {
     let net_addresses = net_settings::get_adresses();
     println!("Network addresses: {}", net_addresses);
     let mut ip_addrs = [
-        IpCidr::new(net_addresses.ipv4_addr, 0),
+        IpCidr::new(IpAddress::Ipv4(Ipv4Address::UNSPECIFIED), 0),
         IpCidr::new(net_addresses.ipv6_ll_addr, 0),
         IpCidr::new(net_addresses.ipv6_ll_addr, 0)
     ];
+    if let net_settings::Ipv4AddrConfig::Static(ipv4) = net_addresses.ipv4_addr {
+        ip_addrs[0] = IpCidr::new(IpAddress::Ipv4(ipv4), 0);
+    }
     let mut interface = match net_addresses.ipv6_addr {
         Some(addr) => {
             ip_addrs[2] = IpCidr::new(addr, 0);

artiq/firmware/libboard_misoc/net_settings.rs

@@ -1,4 +1,6 @@
 use core::fmt;
+use core::fmt::{Display, Formatter};
+use core::str::FromStr;
 
 use smoltcp::wire::{EthernetAddress, IpAddress, Ipv4Address};
 
@@ -7,12 +9,36 @@ use config;
 use i2c_eeprom;
 
 
-pub const USE_DHCP: IpAddress = IpAddress::Ipv4(Ipv4Address::UNSPECIFIED);
+pub enum Ipv4AddrConfig {
+    UseDhcp,
+    Static(Ipv4Address),
+}
+
+impl FromStr for Ipv4AddrConfig {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(if s == "use_dhcp" {
+            Ipv4AddrConfig::UseDhcp
+        } else {
+            Ipv4AddrConfig::Static(Ipv4Address::from_str(s)?)
+        })
+    }
+}
+
+impl Display for Ipv4AddrConfig {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+        match self {
+            Ipv4AddrConfig::UseDhcp => write!(f, "use_dhcp"),
+            Ipv4AddrConfig::Static(ipv4) => write!(f, "{}", ipv4)
+        }
+    }
+}
 
 
 pub struct NetAddresses {
     pub hardware_addr: EthernetAddress,
-    pub ipv4_addr: IpAddress,
+    pub ipv4_addr: Ipv4AddrConfig,
     pub ipv6_ll_addr: IpAddress,
     pub ipv6_addr: Option<IpAddress>
 }
@@ -52,15 +78,9 @@ pub fn get_adresses() -> NetAddresses {
     }
 
     let ipv4_addr;
-    match config::read_str("ip", |r| r.map(|s| {
+    match config::read_str("ip", |r| r.map(|s| s.parse())) {
-        if s == "use_dhcp" {
-            Ok(USE_DHCP)
-        } else {
-            s.parse()
-        }
-    })) {
         Ok(Ok(addr)) => ipv4_addr = addr,
-        _ => ipv4_addr = USE_DHCP,
+        _ => ipv4_addr = Ipv4AddrConfig::UseDhcp,
     }
 
     let ipv6_ll_addr = IpAddress::v6(

artiq/firmware/runtime/main.rs

@@ -32,7 +32,7 @@ use smoltcp::wire::{HardwareAddress, IpAddress, IpCidr, Ipv4Address};
 use board_misoc::{csr, ident, clock, spiflash, config, net_settings, pmp, boot};
 #[cfg(has_ethmac)]
 use board_misoc::ethmac;
-use board_misoc::net_settings::{NetAddresses, USE_DHCP};
+use board_misoc::net_settings::{NetAddresses, Ipv4AddrConfig};
 #[cfg(has_drtio)]
 use board_artiq::drtioaux;
 use board_artiq::drtio_routing;
@@ -100,7 +100,9 @@ pub fn get_ip_addrs(net_addresses: &NetAddresses) -> [IpCidr; IP_ADDRESS_STORAGE
     let mut storage = [
         IpCidr::new(IpAddress::Ipv4(Ipv4Address::UNSPECIFIED), 0);  IP_ADDRESS_STORAGE_SIZE
     ];
-    storage[IPV4_INDEX] = IpCidr::new(net_addresses.ipv4_addr, 0);
+    if let Ipv4AddrConfig::Static(ipv4) = net_addresses.ipv4_addr {
+        storage[IPV4_INDEX] = IpCidr::new(IpAddress::Ipv4(ipv4), 0);
+    }
     storage[IPV6_LL_INDEX] = IpCidr::new(net_addresses.ipv6_ll_addr, 0);
     if let Some(ipv6) = net_addresses.ipv6_addr {
         storage[IPV6_INDEX] = IpCidr::new(ipv6, 0);
@@ -162,7 +164,7 @@ fn startup() {
         smoltcp::iface::NeighborCache::new(alloc::collections::btree_map::BTreeMap::new());
     let net_addresses = net_settings::get_adresses();
     info!("network addresses: {}", net_addresses);
-    let use_dhcp = if net_addresses.ipv4_addr == USE_DHCP {
+    let use_dhcp = if matches!(net_addresses.ipv4_addr, Ipv4AddrConfig::UseDhcp) {
         info!("Will try to acquire an IPv4 address with DHCP");
         true
     } else {