[bootloader] MPU config

bootloader/jump_to_firmware.s

@@ -5,7 +5,5 @@
 .thumb
 .global jump_to_firmware
 jump_to_firmware:
-  dsb 0xF
-  isb 0xF
   msr msp, r0
   bx r1

bootloader/main.cpp

@@ -2,6 +2,7 @@
 #include <ion.h>
 #include <bootloader/slot.h>
 #include <assert.h>
+#include <ion/src/device/shared/drivers/board.h>
 
 #include "interface.h"
 
@@ -23,10 +24,6 @@ void ion_main(int argc, const char * const argv[]) {
     }
   }
 
-  /*
-  KDContext * ctx = KDIonContext::sharedContext();
-  ctx->drawString(Bootloader::s_slotA->version(), KDPoint(0, 20));
-
-  */
+  Ion::Device::Board::bootloaderMPU();
   Bootloader::s_slotA->boot();
 }

ion/src/device/n0110/drivers/board.cpp

@@ -24,6 +24,28 @@ namespace Board {
 
 using namespace Regs;
 
+void bootloaderMPU() {
+  // 1. Disable the MPU
+  // 1.1 Memory barrier
+  Cache::dmb();
+
+  // 1.3 Disable the MPU and clear the control register
+  MPU.CTRL()->setENABLE(false);
+
+  MPU.RNR()->setREGION(7);
+  MPU.RBAR()->setADDR(0x90000000);
+  MPU.RASR()->setXN(false);
+  MPU.RASR()->setENABLE(true);
+
+  // 2.3 Enable MPU
+  MPU.CTRL()->setENABLE(true);
+
+  // 3. Data/instruction synchronisation barriers to ensure that the new MPU configuration is used by subsequent instructions.
+  Cache::disable();
+  Cache::dsb();
+  Cache::isb();
+}
+
 void initMPU() {
   // 1. Disable the MPU
   // 1.1 Memory barrier

ion/src/device/shared/drivers/board.h

@@ -9,6 +9,7 @@ namespace Board {
 
 void init();
 
+void bootloaderMPU();
 void initFPU();
 void initClocks();
 void shutdownClocks(bool keepLEDAwake = false);