1 files changed, 157 insertions, 0 deletions
diff --git a/demo/util.c b/demo/util.c
new file mode 100644
index 0000000..d08ec20
--- /dev/null
+++ b/demo/util.c
@@ -0,0 +1,157 @@
+#include <stddef.h>
+
+#include "demo.h"
+
+static void bad_input(void)
+{
+	print("bad input");
+}
+
+static void unexpected_eof(void)
+{
+	print("unexpected end-of-input");
+}
+
+static int parse_cpu_token(const char *token, unsigned *cpu)
+{
+	if (token[0] != 'c' || token[1] != 'p' || token[2] != 'u'
+	|| !('0' <= token[3] && token[3] < '0' + NUM_CPUS) || token[4]) {
+		bad_input();
+		return -1;
+	}
+
+	*cpu = token[3] - '0';
+	return 0;
+}
+
+int strcmp(const char *s1, const char *s2)
+{
+    while (*s1 && *s1 == *s2)
+        s1++, s2++;
+
+    return (int)*(const unsigned char *)s1 - (int)*(const unsigned char *)s2;
+}
+
+char *strtok_input(char **tokens)
+{
+	char *start = *tokens;
+	while (*start && *start == ' ')
+		++start;
+
+	if (!*start) {
+		*tokens = start;
+		return NULL;
+	}
+
+	char *end = start + 1;
+	while (*end && *end != ' ')
+		++end;
+
+	*tokens = *end ? end + 1 : end;
+	*end = '\0';
+
+	return start;
+}
+
+int parse_cpu(char **tokens, unsigned *cpu)
+{
+	char *token = strtok_input(tokens);
+	if (!token) {
+		unexpected_eof();
+		return -1;
+	}
+
+	return parse_cpu_token(token, cpu);
+}
+
+int parse_cpu_mask(char **tokens, unsigned *mask)
+{
+	*mask = 0;
+
+	char *token;
+	while ((token = strtok_input(tokens))) {
+		unsigned cpu;
+		if (parse_cpu_token(token, &cpu) < 0)
+			return -1;
+
+		*mask |= 1 << cpu;
+	}
+
+	if (!*mask) {
+		print("must specify at least one cpu");
+		return -1;
+	}
+
+	return 0;
+}
+
+int parse_hex(char **tokens, unsigned *val)
+{
+	char *token = strtok_input(tokens);
+	if (!token) {
+		unexpected_eof();
+		return -1;
+	} else if (token[0] != '0' || token[1] != 'x') {
+		bad_input();
+		return -1;
+	}
+
+	*val = 0;
+
+	char *c = &token[2];
+	unsigned nibbles = 0;
+
+	while (*c) {
+		*val <<= 4;
+
+		if ('0' <= *c && *c <= '9')
+			*val |= *c - '0';
+		else if ('a' <= *c && *c <= 'f')
+			*val |= *c - 'a' + 10;
+		else if ('A' <= *c && *c <= 'F')
+			*val |= *c - 'A' + 10;
+
+		++c;
+		++nibbles;
+	}
+
+	if (!nibbles || nibbles > 8) {
+		bad_input();
+		return -1;
+	}
+
+	return 0;
+}
+
+int parse_ptr(char **tokens, void **ptr)
+{
+	unsigned ptr_val;
+	if (parse_hex(tokens, &ptr_val) < 0)
+		return -1;
+
+	*ptr = (void *)ptr_val;
+	return 0;
+}
+
+int parse_aligned(char **tokens, void **ptr)
+{
+	if (parse_ptr(tokens, ptr) < 0)
+		return -1;
+	else if ((unsigned)*ptr & 0b11) {
+		print("unaligned address: %p", *ptr);
+		return -1;
+	}
+
+	return 0;
+}
+
+int expect_end(char **tokens)
+{
+	char *token = strtok_input(tokens);
+	if (token) {
+		print("too many arguments starting from '%s'", token);
+		return -1;
+	}
+
+	return 0;
+}