tools: add tool to decode AML files and build an ACPI namespace

tools/amldecode/table.c

@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include "table.h"
+
+enum loader_status acpi_table_load(const char *path, struct acpi_table **out)
+{
+	FILE *fp = fopen(path, "rb");
+	if (!fp) {
+		return LOADER_IOERR;
+	}
+
+	fseek(fp, 0, SEEK_END);
+	size_t len = ftell(fp);
+	fseek(fp, 0, SEEK_SET);
+
+	unsigned char *buf = malloc(len);
+	if (!buf) {
+		fclose(fp);
+		return LOADER_NOMEM;
+	}
+
+	size_t r = fread(buf, 1, len, fp);
+	if (r != len) {
+		free(buf);
+		fclose(fp);
+		return LOADER_IOERR;
+	}
+
+	fclose(fp);
+
+	size_t sum = 0;
+	for (size_t i = 0; i < len; i++) {
+		sum += buf[i];
+	}
+
+	if ((sum % 0x100) != 0) {
+		free(buf);
+		return LOADER_BADSUM;
+	}
+
+	struct acpi_table *table = (struct acpi_table *)buf;
+	*out = table;
+
+	return LOADER_OK;
+}
+
+void acpi_table_destroy(struct acpi_table *table)
+{
+	free(table);
+}
+
+void acpi_table_get_payload(struct acpi_table *table, void **p, size_t *len)
+{
+	*p = (unsigned char *)table + sizeof *table;
+	*len = table->length;
+}
+
+#define STATUS_STRING(code) \
+	case code: \
+	return #code;
+
+const char *loader_status_string(enum loader_status status)
+{
+	switch (status) {
+	STATUS_STRING(LOADER_OK)
+	STATUS_STRING(LOADER_IOERR)
+	STATUS_STRING(LOADER_BADSUM)
+	STATUS_STRING(LOADER_NOMEM)
+	default:
+		return "<unknown>";
+	}
+}