westfw:
It's questionable whether 115200bps works at 8MHz. Try a lower bitrate.Without DTR/etc, you'll need to do a manual reset, which is a close thing with the existing 1s timeout.
Ok modified Makefile to:
atmega324: CFLAGS += '-DLED_START_FLASHES=5' '-DBAUD_RATE=9600'
Recompiled with "make -l Makefile atmega324".
Uploaded to atmega324a via avrdude, led flashed 5 times.
Holding GND to Reset (i have no pullup on Reset, but it doesn't cause any problems I think) I press enter in the terminal invoking this:
avrdude -P /dev/ttyS0 -b 9600 -c arduino -p m328p -F -v -v -v -v -U flash:w:Blink.cpp.hex
When I see in the terminal screen "avrdude: Send: 0 [30] [20]" I immediately disconnect GND from Reset and then this happens (didn't post everything, just the start):
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Recv: . [14]
avrdude: Recv: . [10]
AVR Part : ATMEGA328P
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PC2
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
eeprom 65 5 4 0 no 1024 4 0 3600 3600 0xff 0xff
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
flash 65 6 128 0 yes 32768 128 256 4500 4500 0xff 0xff
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
lfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
hfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
efuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
lock 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00
Programmer Type : Arduino
Description : Arduino
avrdude: Send: A [41] . [80] [20]
avrdude: Recv: . [14]
avrdude: Recv: . [03]
avrdude: Recv: . [10]
avrdude: Send: A [41] . [81] [20]
avrdude: Recv: . [14]
avrdude: Recv: . [03]
avrdude: Recv: . [10]
avrdude: Send: A [41] . [82] [20]
After it's done, you are greeted with a "Thank you" from avrdude and the LED magically starts to blink in a repetitive 1s interval.
Thank you for your help, it works.