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Diffstat (limited to 'results/classifier/118/peripherals/2462')
| -rw-r--r-- | results/classifier/118/peripherals/2462 | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/results/classifier/118/peripherals/2462 b/results/classifier/118/peripherals/2462 new file mode 100644 index 00000000..4acd39eb --- /dev/null +++ b/results/classifier/118/peripherals/2462 @@ -0,0 +1,69 @@ +peripherals: 0.928 +performance: 0.919 +ppc: 0.897 +user-level: 0.856 +PID: 0.832 +architecture: 0.817 +graphic: 0.811 +permissions: 0.753 +debug: 0.737 +network: 0.716 +device: 0.712 +arm: 0.683 +semantic: 0.672 +files: 0.653 +hypervisor: 0.622 +kernel: 0.615 +assembly: 0.611 +TCG: 0.601 +socket: 0.584 +risc-v: 0.582 +x86: 0.569 +vnc: 0.569 +mistranslation: 0.547 +register: 0.541 +i386: 0.526 +boot: 0.497 +virtual: 0.462 +VMM: 0.442 +KVM: 0.421 + +QEMU SIFIVE reading from stdin hangs +Description of problem: +I have a simple test program (C and ASM) that reads from stdin. When i was using the qemu provided by Ubuntu, QEMU emulator version 8.0.4 (Debian 1:8.0.4+dfsg-1ubuntu3.23.10.5), my test was working, and was able to read bytes from stdin. + +Using the latest Qemu from git, breaks my test. I can still print, but now reading hangs, like its always waiting for input but never getting it. + +My guess is that this commit breaks my code: +https://github.com/qemu/qemu/commit/6ee7ba1b8a10bd8eb1d3b918eaaf9f832a51adb4 + +Before the above commit, `qemu_chr_fe_set_handlers` was being called, and that is what allowed the default behavior of reading from stdin is on by default? + +from sifive_uart.c +``` + qemu_chr_fe_set_handlers(&s->chr, sifive_uart_can_rx, sifive_uart_rx, + sifive_uart_event, sifive_uart_be_change, s, + NULL, true); +``` +Steps to reproduce: +1. compile simple C program that calls `read` reading a single byte from stdin +2. do not initialize UART options +3. run in QEMU, send input, hangs. +Additional information: +Other examples online, like riscv-probe, use a uart init function like below: +``` +static void sifive_uart_init() +{ + uart = (int *)(void *)getauxval(SIFIVE_UART0_CTRL_ADDR); + uint32_t uart_freq = getauxval(UART0_CLOCK_FREQ); + uint32_t baud_rate = getauxval(UART0_BAUD_RATE); + uint32_t divisor = uart_freq / baud_rate - 1; + uart[UART_REG_DIV] = divisor; + uart[UART_REG_TXCTRL] = UART_TXEN; + uart[UART_REG_RXCTRL] = UART_RXEN; + uart[UART_REG_IE] = 0; +} +``` + +However, when I was using QEMU 8.0.4, i did not have to write a function like above to init UART, because stdin and stdout were working out of the box. +Below is my C and ASM: |