diff options
| author | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 07:27:52 +0000 |
|---|---|---|
| committer | Christian Krinitsin <mail@krinitsin.com> | 2025-07-03 07:27:52 +0000 |
| commit | d0c85e36e4de67af628d54e9ab577cc3fad7796a (patch) | |
| tree | f8f784b0f04343b90516a338d6df81df3a85dfa2 /results/classifier/gemma3:12b/peripherals/1525 | |
| parent | 7f4364274750eb8cb39a3e7493132fca1c01232e (diff) | |
| download | qemu-analysis-d0c85e36e4de67af628d54e9ab577cc3fad7796a.tar.gz qemu-analysis-d0c85e36e4de67af628d54e9ab577cc3fad7796a.zip | |
add deepseek and gemma results
Diffstat (limited to 'results/classifier/gemma3:12b/peripherals/1525')
| -rw-r--r-- | results/classifier/gemma3:12b/peripherals/1525 | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/results/classifier/gemma3:12b/peripherals/1525 b/results/classifier/gemma3:12b/peripherals/1525 new file mode 100644 index 000000000..dfaad84c0 --- /dev/null +++ b/results/classifier/gemma3:12b/peripherals/1525 @@ -0,0 +1,79 @@ + +Wrong initial value of stack pointer on AVR devices +Description of problem: +The initial value of stack pointer of AVR MCUs should be RAMEND (address of the end of their RAM), but QEMU initialize them to 0. + +`qemu-system-avr -machine help` lists 4 flavors of MCUs which are ATmega168, ATmega2560, ATmega1280, ATmega328P. According to their datasheets, the stack pointer should be initialized as follows on reset. + +- [ATmega168](https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-9365-Automotive-Microcontrollers-ATmega88-ATmega168_Datasheet.pdf#page=12): RAMEND (which is 0x04FF) +- [ATmega2560 and ATmega1280](https://ww1.microchip.com/downloads/en/devicedoc/atmel-2549-8-bit-avr-microcontroller-atmega640-1280-1281-2560-2561_datasheet.pdf#page=15): RAMEND (which is 0x21FF) +- [ATmega328P](https://ww1.microchip.com/downloads/aemDocuments/documents/MCU08/ProductDocuments/DataSheets/ATmega48A-PA-88A-PA-168A-PA-328-P-DS-DS40002061B.pdf#page=22): RAMEND (which is 0x08FF) +Steps to reproduce: +1. Assemble the assembly code below: `avrasm2 -fI test.asm` + + ```asm + ;; test.asm + .INCLUDE "m328Pdef.inc" + + .EQU F_CPU = 16000000 + .EQU BAUD_RATE = 9600 + .EQU PRESCALE = (F_CPU / (16 * BAUD_RATE)) - 1 + + .CSEG + start: + ;; initialize USART (serial port) + LDI R16, LOW(PRESCALE) + LDI R17, HIGH(PRESCALE) + STS UBRR0L, R16 + STS UBRR0H, R17 + LDI R16, (1 << RXEN0) | (1 << TXEN0) + STS UCSR0B, R16 + + ;; Get stack pointer low byte and print it in ASCII + IN R16, SPL + LDI R17, 0x30 + ADD R16, R17 + print1: + LDS r17, UCSR0A + SBRS r17, UDRE0 + RJMP print1 + STS UDR0, r16 + + ;; Get stack pointer high byte and print it in ASCII + IN R16, SPH + LDI R17, 0x30 + ADD R16, R17 + print2: + LDS r17, UCSR0A + SBRS r17, UDRE0 + RJMP print2 + STS UDR0, r16 + + end: + RJMP end + ``` + +2. Convert it to bin file: `avr-objcopy --input-target=ihex --output-target=binary test.hex test.bin` + +3. Run it with QEMU: `qemu-system-avr -machine uno -bios test.bin -serial stdio` + +This should print 00 which means that the stack pointer is initialized to 0. +Additional information: +I examined the source code and I think that editing the function `avr_cpu_reset_hold` in `/target/avr/cpu.c` might fix this issue. This is my first time seeing QEMU source code, so I might be wrong, though. + +```c +// in /target/avr/cpu.c line 70 +static void avr_cpu_reset_hold(Object *obj) +{ + // ... + + env->rampD = 0; + env->rampX = 0; + env->rampY = 0; + env->rampZ = 0; + env->eind = 0; + env->sp = 0; // <-- change this value in accordance with board type? + + //... +} +``` |