--- /n/sources/plan9/sys/include/libc.h	Wed Sep 18 22:45:28 2013
+++ /sys/include/libc.h	Sun Jun 21 00:00:00 2026
@@ -48,6 +48,23 @@
 	Runemax		= 0x10FFFF,	/* 21-bit rune */
 	Runemask	= 0x1FFFFF,	/* bits used by runes (see grep) */
 };
+
+/*
+ * byte serialization
+ */
+extern	uint	begeth(void *vp);
+extern	uint	begetl(void *vp);
+extern	uvlong	begetvl(void *vp);
+extern	void*	beputh(void *vp, ushort l);
+extern	void*	beputl(void *vp, ulong l);
+extern	void*	beputvl(void *vp, uvlong l);
+
+extern	uint	legeth(void *vp);
+extern	uint	legetl(void *vp);
+extern	uvlong	legetvl(void *vp);
+extern	void*	leputh(void *vp, ushort l);
+extern	void*	leputl(void *vp, ulong l);
+extern	void*	leputvl(void *vp, uvlong l);
 
 /*
  * rune routines
--- /n/sources/plan9/sys/src/libc/port/mkfile	Wed Apr 24 22:51:53 2013
+++ /sys/src/libc/port/mkfile	Sun Jun 21 00:00:00 2026
@@ -12,6 +12,7 @@
 	atof.c\
 	atol.c\
 	atoll.c\
+	byteserial.c\
 	cistrcmp.c\
 	cistrncmp.c\
 	cistrstr.c\
--- /dev/null	Sun Jun 21 20:07:59 2026
+++ /sys/src/libc/port/byteserial.c	Sun Jun 21 00:00:00 2026
@@ -0,0 +1,146 @@
+/*
+ * byte serialization
+ */
+#include <u.h>
+#include <libc.h>
+
+/* convert bytes to integers, by byte order and integer length */
+
+uint
+legeth(void *vp)
+{
+	uchar *p;
+
+	p = vp;
+	return p[1]<<8 | p[0];
+}
+
+uint
+begeth(void *vp)
+{
+	uchar *p;
+
+	p = vp;
+	return p[0]<<8 | p[1];
+}
+
+uint
+legetl(void *vp)
+{
+	uchar *p;
+
+	p = vp;
+	return p[3]<<24 | p[2]<<16 | p[1]<<8 | p[0];
+}
+
+uint
+begetl(void *vp)
+{
+	uchar *p;
+
+	p = vp;
+	return p[0]<<24 | p[1]<<16 | p[2]<<8 | p[3];
+}
+
+uvlong
+legetvl(void *vp)
+{
+	return (uvlong)legetl((uchar *)vp+4) << 32 | legetl(vp);
+}
+
+uvlong
+begetvl(void *vp)
+{
+	return (uvlong)begetl(vp) << 32 | begetl((uchar *)vp+4);
+}
+
+
+/* convert integers to bytes, by byte order and integer length */
+
+void *
+leputh(void *vp, ushort l)
+{
+	uchar *p;
+
+	p = vp;
+	*p++ = l; l >>= 8;
+	*p++ = l;
+	return p;
+}
+
+void *
+beputh(void *vp, ushort l)
+{
+	uchar *p, *ep;
+
+	p = vp;
+	p += sizeof l;
+	ep = p;
+	*--p = l; l >>= 8;
+	*--p = l;
+	return ep;
+}
+
+void *
+leputl(void *vp, ulong l)
+{
+	uchar *p;
+
+	p = vp;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l;
+	return p;
+}
+
+void *
+beputl(void *vp, ulong l)
+{
+	uchar *p, *ep;
+
+	p = vp;
+	p += sizeof l;
+	ep = p;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l;
+	return ep;
+}
+
+void *
+leputvl(void *vp, uvlong l)
+{
+	uchar *p;
+
+	p = vp;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l; l >>= 8;
+	*p++ = l;
+	return p;
+}
+
+void *
+beputvl(void *vp, uvlong l)
+{
+	uchar *p, *ep;
+
+	p = vp;
+	p += sizeof l;
+	ep = p;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l; l >>= 8;
+	*--p = l;
+	return ep;
+}
--- /dev/null	Sun Jun 21 20:07:59 2026
+++ /sys/man/2/byteserial	Sun Jun 21 00:00:00 2026
@@ -0,0 +1,54 @@
+.TH BYTESERIAL 2
+.SH NAME
+byteserial: begeth, begetl, begetvl, beputh, beputl, beputvl, legeth, legetl, legetvl, leputh, leputl, leputvl \- converts integers to bytes, and vice versa, in either byte order
+.SH SYNOPSIS
+.EX
+#include <u.h>
+#include <libc.h>
+.EE
+.PP
+.EX
+uint	begeth(void *vp)
+uint	begetl(void *vp)
+uvlong	begetvl(void *vp)
+void*	beputh(void *vp, ushort l)
+void*	beputl(void *vp, ulong l)
+void*	beputvl(void *vp, uvlong l)
+.EE
+.PP
+.EX
+uint	legeth(void *vp)
+uint	legetl(void *vp)
+uvlong	legetvl(void *vp)
+void*	leputh(void *vp, ushort l)
+void*	leputl(void *vp, ulong l)
+void*	leputvl(void *vp, uvlong l)
+.EE
+.SH DESCRIPTION
+The
+.I get
+functions convert bytes at
+.I vp
+by shifting bytes and OR-ing them into unsigned integers, which they return.
+Host byte order is irrelevant.
+The
+.B be*
+functions assume big-endian (e.g., 68020, MIPS) byte order:
+the first byte is the most significant.
+The
+.B le*
+functions assume little-endian (e.g., 386) byte order:
+the first byte is the least significant.
+.PP
+The
+.I put
+functions do the reverse, converting unsigned integers to bytes at
+.I vp
+and returning the address of the byte after those generated.
+.SH SOURCE
+.B /sys/src/libc/port/byteserial.c
+.SH SEE ALSO
+.IR ip (2)
+.SH BUGS
+Only the common byte orders are supported.
+PDP-11 (a.k.a. middle-endian or German) byte order is not supported.