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authorScott Allen <saydisp-git@yahoo.ca>2017-11-13 17:41:23 +0100
committerMartino Facchin <m.facchin@arduino.cc>2017-11-13 17:41:34 +0100
commit7d4bca50419f2b2e57f92e9bec1cbbbe6d846fc1 (patch)
tree9fe993a839ec06b4faeb3f920ab8031369385319 /cores
parent31223160ebfeb6aef21dded0572003eedb2b8fd1 (diff)
Always read key to check for new LUFA bootloader
Instead of checking for the NEW_LUFA_SIGNATURE once in program memory and then setting a flag which is used for further checks, a function is used that always checks program memory directly. If a flag is used, there's a slight chance that its location in RAM could fall on MAGIC_KEY_POS. In this case, an aborted USB auto-reset sequence may fail.
Diffstat (limited to 'cores')
-rw-r--r--cores/arduino/CDC.cpp9
-rw-r--r--cores/arduino/USBCore.cpp7
-rw-r--r--cores/arduino/USBCore.h3
3 files changed, 7 insertions, 12 deletions
diff --git a/cores/arduino/CDC.cpp b/cores/arduino/CDC.cpp
index 39373f6..142f8f6 100644
--- a/cores/arduino/CDC.cpp
+++ b/cores/arduino/CDC.cpp
@@ -36,8 +36,6 @@ static volatile int32_t breakValue = -1;
static u8 wdtcsr_save;
-bool _updatedLUFAbootloader = false;
-
#define WEAK __attribute__ ((weak))
extern const CDCDescriptor _cdcInterface PROGMEM;
@@ -59,6 +57,11 @@ const CDCDescriptor _cdcInterface =
D_ENDPOINT(USB_ENDPOINT_IN (CDC_ENDPOINT_IN ),USB_ENDPOINT_TYPE_BULK,USB_EP_SIZE,0)
};
+bool isLUFAbootloader()
+{
+ return pgm_read_word(FLASHEND - 1) == NEW_LUFA_SIGNATURE;
+}
+
int CDC_GetInterface(u8* interfaceNum)
{
interfaceNum[0] += 2; // uses 2
@@ -108,7 +111,7 @@ bool CDC_Setup(USBSetup& setup)
#if MAGIC_KEY_POS != (RAMEND-1)
// For future boards save the key in the inproblematic RAMEND
// Which is reserved for the main() return value (which will never return)
- if (_updatedLUFAbootloader) {
+ if (isLUFAbootloader()) {
// horray, we got a new bootloader!
magic_key_pos = (RAMEND-1);
}
diff --git a/cores/arduino/USBCore.cpp b/cores/arduino/USBCore.cpp
index e00fb02..81f689d 100644
--- a/cores/arduino/USBCore.cpp
+++ b/cores/arduino/USBCore.cpp
@@ -35,7 +35,6 @@ extern const u16 STRING_LANGUAGE[] PROGMEM;
extern const u8 STRING_PRODUCT[] PROGMEM;
extern const u8 STRING_MANUFACTURER[] PROGMEM;
extern const DeviceDescriptor USB_DeviceDescriptorIAD PROGMEM;
-extern bool _updatedLUFAbootloader;
const u16 STRING_LANGUAGE[2] = {
(3<<8) | (2+2),
@@ -819,12 +818,6 @@ void USBDevice_::attach()
UDIEN = (1<<EORSTE) | (1<<SOFE) | (1<<SUSPE); // Enable interrupts for EOR (End of Reset), SOF (start of frame) and SUSPEND
TX_RX_LED_INIT;
-
-#if MAGIC_KEY_POS != (RAMEND-1)
- if (pgm_read_word(FLASHEND - 1) == NEW_LUFA_SIGNATURE) {
- _updatedLUFAbootloader = true;
- }
-#endif
}
void USBDevice_::detach()
diff --git a/cores/arduino/USBCore.h b/cores/arduino/USBCore.h
index 18560b6..4210ced 100644
--- a/cores/arduino/USBCore.h
+++ b/cores/arduino/USBCore.h
@@ -285,8 +285,7 @@ typedef struct
// Old Caterina bootloader places the MAGIC key into unsafe RAM locations (it can be rewritten
// by the running sketch before to actual reboot).
// Newer bootloaders, recognizable by the LUFA "signature" at the end of the flash, can handle both
-// the usafe and the safe location. Check once (in USBCore.cpp) if the bootloader in new, then set the global
-// _updatedLUFAbootloader variable to true/false and place the magic key consequently
+// the usafe and the safe location.
#ifndef MAGIC_KEY
#define MAGIC_KEY 0x7777
#endif