1 files changed, 63 insertions, 0 deletions
diff --git a/startup/entry.cpp b/startup/entry.cpp
new file mode 100644
index 0000000..d7385f8
--- /dev/null
+++ b/startup/entry.cpp
@@ -0,0 +1,63 @@
+#include <stdint.h>
+#include <rcc/rcc.h>
+
+int main();
+
+typedef void (*funcp_t)();
+
+// Symbols from linker script.
+extern uint32_t _data_rom;
+extern uint32_t _data_start;
+extern uint32_t _data_end;
+extern uint32_t _bss_start;
+extern uint32_t _bss_end;
+extern funcp_t _init_array_start;
+extern funcp_t _init_array_end;
+extern funcp_t _fini_array_start;
+extern funcp_t _fini_array_end;
+
+void __attribute__((naked)) entry() {
+	// Initialize HAL.
+	rcc_init();
+	
+	// Load .data from rom image.
+	uint32_t* rp = &_data_rom;
+	uint32_t* wp = &_data_start;
+	
+	while(wp < &_data_end) {
+		*wp++ = *rp++;
+	}
+	
+	// Clear .bss.
+	wp = &_bss_start;
+	
+	while(wp < &_bss_end) {
+		*wp++ = 0;
+	}
+	
+	// Call constructors.
+	funcp_t* fp = &_init_array_start;
+	
+	while(fp < &_init_array_end) {
+		(*fp++)();
+	}
+	
+	// Call main().
+	main();
+	
+	// Call destructors.
+	fp = &_fini_array_start;
+	
+	while(fp < &_fini_array_end) {
+		(*fp++)();
+	}
+	
+	// Halt.
+	while(1);
+}
+
+extern "C" void __cxa_pure_virtual() {
+	while (1);
+}
+
+void* __dso_handle = 0;