1 files changed, 119 insertions, 0 deletions
diff --git a/util/libreboot-utils/lib/num.c b/util/libreboot-utils/lib/num.c
new file mode 100644
index 00000000..e13a8853
--- /dev/null
+++ b/util/libreboot-utils/lib/num.c
@@ -0,0 +1,119 @@
+/* SPDX-License-Identifier: MIT
+ * Copyright (c) 2026 Leah Rowe <leah@libreboot.org>
+ *
+ * Non-randomisation-related numerical functions.
+ * For rand functions, see: rand.c
+ */
+
+#ifdef __OpenBSD__
+#include <sys/param.h>
+#endif
+#include <sys/types.h>
+
+#include <errno.h>
+#if !((defined(__OpenBSD__) && (OpenBSD) >= 201) || \
+    defined(__FreeBSD__) || \
+    defined(__NetBSD__) || defined(__APPLE__))
+#include <fcntl.h> /* if not arc4random: /dev/urandom */
+#endif
+#include <ctype.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../include/common.h"
+
+unsigned short
+hextonum(char ch_s)
+{
+	int saved_errno = errno;
+
+	unsigned char ch;
+	size_t rval;
+
+	ch = (unsigned char)ch_s;
+
+	if ((unsigned int)(ch - '0') <= 9)
+		return ch - '0';
+
+	ch |= 0x20;
+
+	if ((unsigned int)(ch - 'a') <= 5)
+		return ch - 'a' + 10;
+
+	if (ch == '?' || ch == 'x')
+		return rsize(16); /* <-- with rejection sampling! */
+
+	return 16;
+}
+
+/* basically hexdump -C */
+/*
+	TODO: optimise this
+	write a full util for hexdump
+	how to optimise:
+	don't call print tens of thousands of times!
+	convert the numbers manually, and cache everything
+	in a BUFSIZ sized buffer, with everything properly
+	aligned. i worked out that i could fit 79 rows
+	in a 8KB buffer (1264 bytes of numbers represented
+	as strings in hex)
+	this depends on the OS, and would be calculated at
+	runtime.
+	then:
+	don't use printf. just write it to stdout (basically
+	a simple cat implementation)
+*/
+void
+spew_hex(const void *data, size_t len)
+{
+	const unsigned char *buf = (const unsigned char *)data;
+	unsigned char c;
+	size_t i;
+	size_t j;
+
+	if (buf == NULL ||
+	    len == 0)
+		return;
+
+	for (i = 0; i < len; i += 16) {
+
+		if (len <= 4294967296) /* below 4GB */
+			printf("%08zx  ", i);
+		else
+			printf("%0*zx  ", sizeof(size_t) * 2, i);
+
+		for (j = 0; j < 16; j++) {
+
+			if (i + j < len)
+				printf("%02x ", buf[i + j]);
+			else
+				printf("   ");
+
+			if (j == 7)
+				printf(" ");
+		}
+
+		printf(" |");
+
+		for (j = 0; j < 16 && i + j < len; j++) {
+
+			c = buf[i + j];
+			printf("%c", isprint(c) ? c : '.');
+		}
+
+		printf("|\n");
+	}
+
+	printf("%08zx\n", len);
+}
+
+void
+check_bin(size_t a, const char *a_name)
+{
+	if (a > 1)
+		err_exit(EINVAL, "%s must be 0 or 1, but is %lu",
+		    a_name, (size_t)a);
+}