1 files changed, 75 insertions, 0 deletions
diff --git a/common/main.c b/common/main.c
new file mode 100644
index 0000000..fb388cb
--- /dev/null
+++ b/common/main.c
@@ -0,0 +1,75 @@
+/*
+ * main.c - the C entry. console up first, then load the payload and
+ * jump. called from start.S with x0 = whatever the firmware passed.
+ *
+ * the osdev model, arm64: the firmware services do the work, the
+ * kernel goes at a fixed known address, whatever x0 we were handed
+ * goes straight through to the payload.
+ *
+ * Copyright (c) 2026 Bradley Morgan <brads@mainlining.org>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files
+ * (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge,
+ * publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
+ * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <stdint.h>
+#include <debug.h>
+#include <semihosting.h>
+#include <boot.h>
+
+#define TB_VERSION "0.1"
+
+extern int tb_console_init(void);
+
+/*
+ * fixed load address, the osdev way. past the bootloader at the
+ * bottom of RAM, the image header decides its final resting place.
+ */
+#define TB_LOAD_ADDR	0x40200000
+
+/* the file semihosting serves as the payload */
+#define TB_BOOTFILE	"Image"
+
+extern void __NO_RETURN tb_boot_linux(uintptr_t ep, uintptr_t fw_arg);
+
+void tashaboot_main(uintptr_t fw_arg)
+{
+	struct tb_image img;
+	int ret;
+
+	if (tb_console_init())
+		return;
+
+	dprintf(ALWAYS, "tashaboot " TB_VERSION "\n");
+
+	ret = tb_load_semihosting(TB_BOOTFILE, TB_LOAD_ADDR, &img);
+	if (ret) {
+		dprintf(ALWAYS, "load failed (%d), halting\n", ret);
+		platform_halt();
+	}
+
+	dprintf(ALWAYS, "loaded %llu bytes at %lx, entry %lx\n",
+		(unsigned long long)img.size, img.load, img.ep);
+	dprintf(ALWAYS, "jumping\n");
+
+	tb_boot_linux(img.ep, fw_arg);
+}