Move fdt handling logic out of main.c.
This is in preparation for having archs/platforms that don't use FDT.
diff --git a/src/memiter.c b/src/memiter.c
new file mode 100644
index 0000000..d3d37d2
--- /dev/null
+++ b/src/memiter.c
@@ -0,0 +1,103 @@
+#include "memiter.h"
+
+#include "std.h"
+
+/**
+ * Initialises the given memory iterator.
+ */
+void memiter_init(struct memiter *it, const void *data, size_t size)
+{
+ it->next = data;
+ it->limit = it->next + size;
+}
+
+/**
+ * Determines if the next character is a whitespace.
+ */
+static bool memiter_isspace(struct memiter *it)
+{
+ switch (*it->next) {
+ case ' ':
+ case '\t':
+ case '\n':
+ case '\r':
+ return true;
+ default:
+ return false;
+ }
+}
+
+/**
+ * Moves iterator to the next non-whitespace character.
+ */
+static void memiter_skip_space(struct memiter *it)
+{
+ while (it->next < it->limit && memiter_isspace(it)) {
+ it->next++;
+ }
+}
+
+/**
+ * Compares the iterator to a null-terminated string.
+ */
+bool memiter_iseq(const struct memiter *it, const char *str)
+{
+ size_t len = strlen(str);
+ if (len != it->limit - it->next) {
+ return false;
+ }
+ return memcmp(it->next, str, len) == 0;
+}
+
+/**
+ * Retrieves the next string that is delimited by whitespaces. The result is
+ * stored in "str".
+ */
+bool memiter_parse_str(struct memiter *it, struct memiter *str)
+{
+ /* Skip all white space and fail if we reach the end of the buffer. */
+ memiter_skip_space(it);
+ if (it->next >= it->limit) {
+ return false;
+ }
+
+ str->next = it->next;
+
+ /* Find the end of the string. */
+ while (it->next < it->limit && !memiter_isspace(it)) {
+ it->next++;
+ }
+
+ str->limit = it->next;
+
+ return true;
+}
+
+/**
+ * Parses the next string that represents a 64-bit number.
+ */
+bool memiter_parse_uint(struct memiter *it, uint64_t *value)
+{
+ uint64_t v = 0;
+
+ /* Skip all white space and fail if we reach the end of the buffer. */
+ memiter_skip_space(it);
+ if (it->next >= it->limit) {
+ return false;
+ }
+
+ /* Fail if it's not a number. */
+ if (*it->next < '0' || *it->next > '9') {
+ return false;
+ }
+
+ /* Parse the number. */
+ do {
+ v = v * 10 + *it->next - '0';
+ it->next++;
+ } while (it->next < it->limit && *it->next >= '0' && *it->next <= '9');
+
+ *value = v;
+
+ return true;
+}