1 files changed, 210 insertions, 0 deletions
diff --git a/src/loader/config.c b/src/loader/config.c
new file mode 100644
index 0000000..2471d87
--- /dev/null
+++ b/src/loader/config.c
@@ -0,0 +1,210 @@
+// MIT License, Copyright (c) 2021 Marvin Borner
+
+#include <config.h>
+#include <device.h>
+#include <protocols/all.h>
+#include <library.h>
+#include <log.h>
+#include <panic.h>
+
+// Keys
+#define TIMEOUT "TIMEOUT"
+#define PATH "PATH"
+
+// Config structure
+static struct cfg cfg = { 0 };
+
+// Config file contents (if found)
+static char file[1024] = { 0 };
+
+// Find config file
+static u8 config_find(struct dev *dev)
+{
+	if (!dev->p.disk.fs.read)
+		return 0; // No fs found or not readable - continue!
+
+	s32 res = dev->p.disk.fs.read("/boot/segelboot.cfg", file, 0, sizeof(file), dev);
+	if (res > 0)
+		return 1; // Break foreach
+
+	// Continue foreach
+	return 0;
+}
+
+// Checks if index is appropriate as some key/value need to be in entry
+static void config_in_entry(u8 index)
+{
+	if (index == 0xff)
+		panic("No entry name given\n");
+}
+
+// Add/overwrite value by key and entry index
+static void config_add(u8 index, enum config_key key, const char *value)
+{
+	struct config_entry *entry = &cfg.entry[index];
+	entry->exists = 1;
+
+	switch (key) {
+	case CONFIG_NAME:
+		config_in_entry(index);
+		strlcpy(entry->name, value, sizeof(entry->name));
+		break;
+	case CONFIG_TIMEOUT:
+		cfg.timeout = atoi(value);
+		break;
+	case CONFIG_PATH:
+		config_in_entry(index);
+		strlcpy(entry->full_path, value, sizeof(entry->full_path));
+		break;
+	case CONFIG_NONE:
+	default:
+		panic("Invalid config\n");
+	}
+}
+
+// TODO: This code is kind of messy
+// Structure per line: KEY=VALUE
+static void config_parse(void)
+{
+	// Entry index
+	u8 entry = 0xff;
+
+	// Value per key
+	char value[64] = { 0 };
+	u8 value_index = 0;
+
+	// States
+	enum config_key current = CONFIG_NONE; // Value key type
+	u8 state = 0; // 0 is key, 1 is value, 2 is entry
+
+	const char *start = file; // Start is at the beginning of the key
+	for (const char *p = start; *p; p++) {
+		if (state == 0) {
+			// We're at key parsing
+			if (*p == '\n') { // A key can't just end but ok
+				start = p + 1;
+			} else if (*p == '#') {
+				state = 2; // Let's parse the entry name
+				p++;
+				continue;
+			} else if (*p != '=') {
+				continue;
+			}
+
+			// The key is now at start until p
+			u8 diff = p - start;
+
+			// Timeout key
+			if (diff == sizeof(TIMEOUT) - 1 && memcmp(start, TIMEOUT, diff) == 0) {
+				current = CONFIG_TIMEOUT;
+				state = 1;
+				continue;
+			}
+
+			// Path key
+			if (diff == sizeof(PATH) - 1 && memcmp(start, PATH, diff) == 0) {
+				current = CONFIG_PATH;
+				state = 1;
+				continue;
+			}
+		} else if (state == 1) {
+			// We're at value parsing
+			assert(value_index + 1 < (u8)sizeof(value));
+			if (*p == '\n') { // Finished
+				value[value_index] = 0;
+				config_add(entry, current, value);
+				value_index = 0;
+				state = 0;
+				p--; // Repeat parse normally
+			} else {
+				value[value_index++] = *p;
+			}
+		} else if (state == 2) {
+			// We're at entry name parsing
+			assert(value_index + 1 < (u8)sizeof(value));
+			if (*p == '\n') { // Finished
+				entry = entry == 0xff ? 0 : entry + 1;
+				value[value_index] = 0;
+				config_add(entry, CONFIG_NAME, value);
+				value_index = 0;
+				state = 0;
+				p--; // Repeat parse normally
+			} else {
+				value[value_index++] = *p;
+			}
+		}
+	}
+}
+
+// Extract the disk from path by returning index of delimiter or 0xff
+// Example: disk:/boot/config.cfg returns 4 (:)
+static u8 config_path_disk(const char *path)
+{
+	for (const char *p = path; *p; p++)
+		if (*p == ':')
+			return p - path;
+	return 0xff;
+}
+
+// Find matching disk dev for every entry and verify path existence and readability
+static void config_verify(void)
+{
+	for (u8 i = 0; i < COUNT(cfg.entry) && cfg.entry[i].exists; i++) {
+		struct config_entry *entry = &cfg.entry[i];
+
+		u8 len = config_path_disk(entry->full_path);
+		struct dev *dev = device_get_by_name(entry->full_path, len);
+		if (!dev || dev->type != DEVICE_DISK)
+			panic("Invalid device in config\n");
+		entry->dev = dev;
+
+		if (!dev->p.disk.fs.read)
+			panic("Device fs not readable\n");
+
+		// This is now the correct path (due to "disk:PATH")
+		const char *path = &entry->full_path[len + 1];
+		entry->path = path;
+
+		u8 buf[1] = { 0 }; // Just for existence-check
+		s32 ret = dev->p.disk.fs.read(path, buf, 0, sizeof(buf), dev);
+		if (ret != 1 || !buf[0])
+			panic("Path is invalid\n");
+
+		if (!impl_detect(entry))
+			panic("No boot implementation found\n");
+	}
+}
+
+// Call cb for each entry config
+void config_foreach(u8 (*cb)(struct config_entry *))
+{
+	for (u8 i = 0; i < COUNT(cfg.entry) && cfg.entry[i].exists; i++) {
+		if (cb(&cfg.entry[i])) // 1 means break
+			break;
+	}
+}
+
+// Print all configs and entry values
+static void config_print(void)
+{
+	log("[CFG] Global: %d\n", cfg.timeout);
+
+	for (u8 i = 0; i < COUNT(cfg.entry) && cfg.entry[i].exists; i++)
+		log("[CFG] Entry: %s at %s\n", cfg.entry[i].name, cfg.entry[i].full_path);
+}
+
+// Execute entry implementation
+void config_exec(struct config_entry *entry)
+{
+	impl_exec(entry);
+}
+
+void config_read(void)
+{
+	device_foreach(DEVICE_DISK, &config_find);
+	if (!file[0])
+		panic("No config found\n");
+	config_parse();
+	config_verify();
+	config_print();
+}