bootloader: Sanitize global interrupt handling.

We now disable interrupts before jumping to application,
as overwriting the VTOR with interrupts enabled is rather risky.

Also don't assume that interrupts are enabled when the bootloader
is run -- enable them explicitly when we need them.

diff --git a/src/bootloader/main.rs b/src/bootloader/main.rs
index ca459fdc2eccf1c406b52b6423e8d40aab307be9..afd28dc994ca0794e33eb7f8d62d69dfda88d7db 100644 (file)
--- a/src/bootloader/main.rs
+++ b/src/bootloader/main.rs
@@ -40,6 +40,9 @@ use common::usb_serial;
 type Reg32 = register::Register<u32>;
 
 extern {
+    fn enable_interrupts();
+    fn disable_interrupts();
+
     fn jump_to_application(address: u32);
 }
 
@@ -84,6 +87,8 @@ pub unsafe extern fn main() {
     port::set_af(port::PORTE, 24, 1);
     port::set_pull(port::PORTE, 24, port::Pull::Up);
 
+    enable_interrupts();
+
     if application_missing() || bootloader_requested() {
         usb_serial::init(0xf055, USB_PID);
 
@@ -95,5 +100,7 @@ pub unsafe extern fn main() {
         usb_serial::shutdown();
     }
 
+    disable_interrupts();
+
     jump_to_application(APPLICATION_ADDR);
 }