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[AVR] Discover newer bootloader at runtime

Replaces #4280, only checks for the bootloader once

Tested with Hoodloader2, should work with every LUFA-derived bootloader released after 2014 (.apitable_signatures section must be placed at end of the flash)

BootloaderAPITable.S :

.global BootloaderAPI_Signatures
BootloaderAPI_Signatures:

    .long BOOT_START_ADDR ; Start address of the bootloader
    .word 0xDF00 ; Signature for the CDC class bootloader
    .word 0xDCFB ; Signature for a LUFA class bootloader

makefile:

BOOT_API_LD_FLAGS    += $(call BOOT_SECTION_LD_FLAG, .apitable_signatures,  BootloaderAPI_Signatures,  8)
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facchinm committed Apr 6, 2016
1 parent f74afc4 commit 4c901d3f9f347177b3f263c451885ddc3b1b6ab0
@@ -34,6 +34,8 @@ typedef struct
static volatile LineInfo _usbLineInfo = { 57600, 0x00, 0x00, 0x00, 0x00 };
static volatile int32_t breakValue = -1;
bool _updatedLUFAbootloader = false;
#define WEAK __attribute__ ((weak))
extern const CDCDescriptor _cdcInterface PROGMEM;
@@ -99,24 +101,32 @@ bool CDC_Setup(USBSetup& setup)
// with a relatively long period so it can finish housekeeping tasks
// like servicing endpoints before the sketch ends
#ifndef MAGIC_KEY
#define MAGIC_KEY 0x7777
#endif
#ifndef MAGIC_KEY_POS
#define MAGIC_KEY_POS 0x0800
uint16_t magic_key_pos = MAGIC_KEY_POS;
// If we don't use the new RAMEND directly, check manually if we have a newer bootloader.
// This is used to keep compatible with the old leonardo bootloaders.
// You are still able to set the magic key position manually to RAMEND-1 to save a few bytes for this check.
#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) {
// horray, we got a new bootloader!
magic_key_pos = (RAMEND-1);
}
#endif
// We check DTR state to determine if host port is open (bit 0 of lineState).
if (1200 == _usbLineInfo.dwDTERate && (_usbLineInfo.lineState & 0x01) == 0)
{
#if MAGIC_KEY_POS != (RAMEND-1)
*(uint16_t *)(RAMEND-1) = *(uint16_t *)MAGIC_KEY_POS;
*(uint16_t *)MAGIC_KEY_POS = MAGIC_KEY;
#else
// for future boards save the key in the inproblematic RAMEND
// which is reserved for the main() return value (which will never return)
*(uint16_t *)MAGIC_KEY_POS = MAGIC_KEY;
// Backup ram value if its not a newer bootloader.
// This should avoid memory corruption at least a bit, not fully
if (magic_key_pos != (RAMEND-1)) {
*(uint16_t *)(RAMEND-1) = *(uint16_t *)magic_key_pos;
}
#endif
// Store boot key
*(uint16_t *)magic_key_pos = MAGIC_KEY;
wdt_enable(WDTO_120MS);
}
else
@@ -129,10 +139,15 @@ bool CDC_Setup(USBSetup& setup)
wdt_disable();
wdt_reset();
#if MAGIC_KEY_POS != (RAMEND-1)
*(uint16_t *)MAGIC_KEY_POS = *(uint16_t *)(RAMEND-1);
#else
*(uint16_t *)MAGIC_KEY_POS = 0x0000;
// Restore backed up (old bootloader) magic key data
if (magic_key_pos != (RAMEND-1)) {
*(uint16_t *)magic_key_pos = *(uint16_t *)(RAMEND-1);
} else
#endif
{
// Clean up RAMEND key
*(uint16_t *)magic_key_pos = 0x0000;
}
}
}
return true;
@@ -35,6 +35,7 @@ extern const u8 STRING_PRODUCT[] PROGMEM;
extern const u8 STRING_MANUFACTURER[] PROGMEM;
extern const DeviceDescriptor USB_DeviceDescriptor PROGMEM;
extern const DeviceDescriptor USB_DeviceDescriptorB PROGMEM;
extern bool _updatedLUFAbootloader;
const u16 STRING_LANGUAGE[2] = {
(3<<8) | (2+2),
@@ -806,6 +807,12 @@ 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()
@@ -366,4 +366,22 @@ const uint8_t PROGMEM analog_pin_to_channel_PGM[] = {
// Alias SerialUSB to Serial
#define SerialUSB SERIAL_PORT_USBVIRTUAL
// Bootloader related fields
// Old Caterian 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
#ifndef MAGIC_KEY
#define MAGIC_KEY 0x7777
#endif
#ifndef MAGIC_KEY_POS
#define MAGIC_KEY_POS 0x0800
#endif
#ifndef NEW_LUFA_SIGNATURE
#define NEW_LUFA_SIGNATURE 0xDCFB
#endif
#endif /* Pins_Arduino_h */

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