1 files changed, 33 insertions, 0 deletions
diff --git a/src/boot/loader_stage2.c b/src/boot/loader_stage2.c
new file mode 100644
index 0000000..fc3ae1c
--- /dev/null
+++ b/src/boot/loader_stage2.c
@@ -0,0 +1,33 @@
+#include <stddef.h>
+#include <stdint.h>
+#include "uart.h"
+#include "io.h"
+#include "global.h"
+
+void *const kernel_load_addr = ((void*) 0x8000);
+
+void _stage2_main(uint32_t r0, uint32_t r1, uint32_t atags)
+{
+  uart_init();
+
+  // get kernel size via uart (little endian)
+  uint32_t b0, b1, b2, b3;
+  
+  b0 = getchar();
+  b1 = getchar();
+  b2 = getchar();
+  b3 = getchar();
+  
+  uint32_t kernel_size = b0 | (b1 << 8) | (b2 << 16) | (b3 << 24);
+
+  // load kernel at kernel_load_addr
+  char *dst = kernel_load_addr, *end = dst + kernel_size;
+
+  while (dst < end)
+    *(dst++) = getchar();
+
+  // jump to kernel
+  ((void(*)(uint32_t, uint32_t, uint32_t)) kernel_load_addr)
+    (r0, r1, atags);
+}
+