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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/arduino/CDC.cpp
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/arduino/CDC.cpp')
-rw-r--r--cores/arduino/CDC.cpp9
1 files changed, 6 insertions, 3 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);
}