kernel_args: redo implementation

kernel-src/sys/kernel_args.c

@@ -0,0 +1,82 @@
+#include <kernel/kernel_args.h>
+#include <kernel/alloc.h>
+#include <hashtable.h>
+#include <limine.h>
+#include <logging.h>
+
+#define TOTAL_ARGUMENTS_CHARACTER_LIMIT 4096
+
+static volatile struct limine_kernel_file_request kernel_file_request = {
+	.id = LIMINE_KERNEL_FILE_REQUEST,
+	.revision = 0
+};
+
+static size_t allocated = 0;
+static char argument_buffer[TOTAL_ARGUMENTS_CHARACTER_LIMIT];
+
+extern kernel_argument_t *kernel_arguments[];
+extern kernel_argument_t *kernel_arguments_end[];
+
+static void insert_argument(const char *key, const char *value) {
+	size_t argument_count = ((uintptr_t)kernel_arguments_end - (uintptr_t)kernel_arguments) / sizeof(kernel_argument_t *);
+	char *buffer = &argument_buffer[allocated];
+	if (value) {
+		strcpy(buffer, value);
+		allocated += strlen(value) + 1;
+	}
+
+	for (int i = 0; i < argument_count; ++i) {
+		if (strcmp(kernel_arguments[i]->key, key))
+			continue;
+
+		kernel_arguments[i]->found = true;
+
+		switch (kernel_arguments[i]->type) {
+			case KERNEL_ARGUMENT_TYPE_STR:
+				kernel_arguments[i]->value_str = value ? buffer : NULL;
+				break;
+			case KERNEL_ARGUMENT_TYPE_INT:
+				kernel_arguments[i]->value_int = value ? atoll(buffer) : 0;
+				break;
+		}
+	}
+}
+
+void kernel_arguments_parse(void) {
+	__assert(kernel_file_request.response);
+	const char *cmdline = kernel_file_request.response->kernel_file->cmdline;
+	__assert(cmdline);
+	size_t length = min(strlen(cmdline), TOTAL_ARGUMENTS_CHARACTER_LIMIT);
+	char temp_buffer[length];
+	memcpy(temp_buffer, cmdline, length);
+
+	bool escaping = false;
+	const char *key = temp_buffer[0] == ' ' ? NULL : temp_buffer;
+	const char *value = NULL;
+	for (int i = 0; i < length; ++i) {
+		if (temp_buffer[i] == '"') {
+			escaping = !escaping;
+			temp_buffer[i] = '\0';
+			continue;
+		}
+
+		if (temp_buffer[i] == '=') {
+			value = &temp_buffer[i + 1];
+			temp_buffer[i] = '\0';
+			continue;
+		}
+
+		if (temp_buffer[i] == ' ' && !escaping) {
+			temp_buffer[i] = '\0';
+
+			if (key)
+				insert_argument(key, value);
+
+			key = &temp_buffer[i + 1];
+			value = NULL;
+		}
+	}
+
+	if (key != temp_buffer + length)
+		insert_argument(key, value);
+}