diff --git a/lib/std/Thread.zig b/lib/std/Thread.zig
index d7bcbee66f7f0564cdf51183e18f07dc259dd402..e2ee51e1dc95cb94dcb33cb96d4eaf06e35ecc30 100644
--- a/lib/std/Thread.zig
+++ b/lib/std/Thread.zig
@@ -624,7 +624,7 @@ const PosixThreadImpl = struct {
             .openbsd => {
                 var count: c_int = undefined;
                 var count_size: usize = @sizeOf(c_int);
-                const mib = [_]c_int{ os.CTL.HW, os.system.HW_NCPUONLINE };
+                const mib = [_]c_int{ os.CTL.HW, os.system.HW.NCPUONLINE };
                 os.sysctl(&mib, &count, &count_size, null, 0) catch |err| switch (err) {
                     error.NameTooLong, error.UnknownName => unreachable,
                     else => |e| return e,
diff --git a/lib/std/c/dragonfly.zig b/lib/std/c/dragonfly.zig
index 64a79710a40a42bf1f4c14abb0ebfe8968db45b2..824fc2757eab5b3a2bcdb97743b0324db179b13e 100644
--- a/lib/std/c/dragonfly.zig
+++ b/lib/std/c/dragonfly.zig
@@ -9,7 +9,7 @@ pub fn _errno() *c_int {
     return &errno;
 }
 
-pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) usize;
+pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) c_int;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
 pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize;
 pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
diff --git a/lib/std/c/freebsd.zig b/lib/std/c/freebsd.zig
index b3e6c6769ac0964cab514faa42d386d9da4bfb57..b351128b0324f105e04090a66986c0857215be19 100644
--- a/lib/std/c/freebsd.zig
+++ b/lib/std/c/freebsd.zig
@@ -75,7 +75,7 @@ pub const _errno = __error;
 
 pub extern "c" var malloc_options: [*:0]const u8;
 
-pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) usize;
+pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) isize;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
 pub extern "c" fn getrandom(buf_ptr: [*]u8, buf_len: usize, flags: c_uint) isize;
 pub extern "c" fn getentropy(buf_ptr: [*]u8, buf_len: usize) c_int;
diff --git a/lib/std/c/openbsd.zig b/lib/std/c/openbsd.zig
index dc5f8a14c9fa252ad50d7aab8c95c495374b40ea..93681b77e18b70499a03e5873c3895619abb617d 100644
--- a/lib/std/c/openbsd.zig
+++ b/lib/std/c/openbsd.zig
@@ -16,7 +16,7 @@ pub extern "c" fn arc4random_buf(buf: [*]u8, len: usize) void;
 pub extern "c" fn getthrid() pid_t;
 pub extern "c" fn pipe2(fds: *[2]fd_t, flags: u32) c_int;
 
-pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) usize;
+pub extern "c" fn getdents(fd: c_int, buf_ptr: [*]u8, nbytes: usize) c_int;
 pub extern "c" fn sigaltstack(ss: ?*stack_t, old_ss: ?*stack_t) c_int;
 
 pub const pthread_mutex_t = extern struct {
@@ -1606,31 +1606,34 @@ pub const KERN = struct {
     pub const PROC_NENV = 4;
 };
 
-pub const HW_MACHINE = 1;
-pub const HW_MODEL = 2;
-pub const HW_NCPU = 3;
-pub const HW_BYTEORDER = 4;
-pub const HW_PHYSMEM = 5;
-pub const HW_USERMEM = 6;
-pub const HW_PAGESIZE = 7;
-pub const HW_DISKNAMES = 8;
-pub const HW_DISKSTATS = 9;
-pub const HW_DISKCOUNT = 10;
-pub const HW_SENSORS = 11;
-pub const HW_CPUSPEED = 12;
-pub const HW_SETPERF = 13;
-pub const HW_VENDOR = 14;
-pub const HW_PRODUCT = 15;
-pub const HW_VERSION = 16;
-pub const HW_SERIALNO = 17;
-pub const HW_UUID = 18;
-pub const HW_PHYSMEM64 = 19;
-pub const HW_USERMEM64 = 20;
-pub const HW_NCPUFOUND = 21;
-pub const HW_ALLOWPOWERDOWN = 22;
-pub const HW_PERFPOLICY = 23;
-pub const HW_SMT = 24;
-pub const HW_NCPUONLINE = 25;
+pub const HW = struct {
+    pub const MACHINE = 1;
+    pub const MODEL = 2;
+    pub const NCPU = 3;
+    pub const BYTEORDER = 4;
+    pub const PHYSMEM = 5;
+    pub const USERMEM = 6;
+    pub const PAGESIZE = 7;
+    pub const DISKNAMES = 8;
+    pub const DISKSTATS = 9;
+    pub const DISKCOUNT = 10;
+    pub const SENSORS = 11;
+    pub const CPUSPEED = 12;
+    pub const SETPERF = 13;
+    pub const VENDOR = 14;
+    pub const PRODUCT = 15;
+    pub const VERSION = 16;
+    pub const SERIALNO = 17;
+    pub const UUID = 18;
+    pub const PHYSMEM64 = 19;
+    pub const USERMEM64 = 20;
+    pub const NCPUFOUND = 21;
+    pub const ALLOWPOWERDOWN = 22;
+    pub const PERFPOLICY = 23;
+    pub const SMT = 24;
+    pub const NCPUONLINE = 25;
+    pub const POWER = 26;
+};
 
 /// TODO refines if necessary
 pub const PTHREAD_STACK_MIN = switch (builtin.cpu.arch) {
diff --git a/lib/std/fs.zig b/lib/std/fs.zig
index 38b94873e6213efdb1f69a8aa2205c2fec757024..bb0890be4ba7ba7fdf53991b922f48fc8292317f 100644
--- a/lib/std/fs.zig
+++ b/lib/std/fs.zig
@@ -478,6 +478,9 @@ pub const IterableDir = struct {
                             .FAULT => unreachable,
                             .NOTDIR => unreachable,
                             .INVAL => unreachable,
+                            // Introduced in freebsd 13.2: directory unlinked but still open.
+                            // To be consistent, iteration ends if the directory being iterated is deleted during iteration.
+                            .NOENT => return null,
                             else => |err| return os.unexpectedErrno(err),
                         }
                         if (rc == 0) return null;
diff --git a/lib/std/os.zig b/lib/std/os.zig
index 20f7e4ce222cd5bae9d4feae86d1b6686f34b9dd..4699d0186c79ec75b648f3953963f7b47615817e 100644
--- a/lib/std/os.zig
+++ b/lib/std/os.zig
@@ -88,6 +88,10 @@ pub const F = system.F;
 pub const FD_CLOEXEC = system.FD_CLOEXEC;
 pub const Flock = system.Flock;
 pub const HOST_NAME_MAX = system.HOST_NAME_MAX;
+pub const HW = switch (builtin.os.tag) {
+    .openbsd => system.HW,
+    else => .{},
+};
 pub const IFNAMESIZE = system.IFNAMESIZE;
 pub const IOV_MAX = system.IOV_MAX;
 pub const IPPROTO = system.IPPROTO;
diff --git a/lib/std/process.zig b/lib/std/process.zig
index 6ad0df868ead2cff24b4059d05ebcce81d934ccc..f27b7e835b10540acc252688494b218bf66ffa9a 100644
--- a/lib/std/process.zig
+++ b/lib/std/process.zig
@@ -1163,7 +1163,7 @@ pub fn totalSystemMemory() TotalSystemMemoryError!usize {
         .linux => {
             return totalSystemMemoryLinux() catch return error.UnknownTotalSystemMemory;
         },
-        .freebsd, .netbsd, .openbsd, .dragonfly, .macos => {
+        .freebsd, .netbsd, .dragonfly, .macos => {
             var physmem: c_ulong = undefined;
             var len: usize = @sizeOf(c_ulong);
             const name = switch (builtin.os.tag) {
@@ -1177,6 +1177,23 @@ pub fn totalSystemMemory() TotalSystemMemoryError!usize {
             };
             return @intCast(usize, physmem);
         },
+        .openbsd => {
+            const mib: [2]c_int = [_]c_int{
+                std.os.CTL.HW,
+                std.os.HW.PHYSMEM64,
+            };
+            var physmem: i64 = undefined;
+            var len: usize = @sizeOf(@TypeOf(physmem));
+            std.os.sysctl(&mib, &physmem, &len, null, 0) catch |err| switch (err) {
+                error.NameTooLong => unreachable, // constant, known good value
+                error.PermissionDenied => unreachable, // only when setting values,
+                error.SystemResources => unreachable, // memory already on the stack
+                error.UnknownName => unreachable, // constant, known good value
+                else => return error.UnknownTotalSystemMemory,
+            };
+            assert(physmem >= 0);
+            return @bitCast(usize, physmem);
+        },
         .windows => {
             var sbi: std.os.windows.SYSTEM_BASIC_INFORMATION = undefined;
             const rc = std.os.windows.ntdll.NtQuerySystemInformation(