RetroBSD на QEMU

[vak]

Внезапно выяснилось, что в RetroBSD была старая ошибка, из-за которой он не запускался на QEMU. Инструкция ERET попадала в delay-слот условного перехода. Строго говоря, это неопределённое поведение. В железе на PIC32 оно работает, но симулятор такого не прощает. Поправил, теперь всё с порядке.

$ qemu-pic32 -machine pic32mx7-max32 -nographic -monitor none -serial stdio -bios boot-max32.hex -kernel unix.hex -sd retrobsd.img
Board: chipKIT Max32
Processor: M4K
RAM size: 128 kbytes
Load file: 'boot-max32.hex', 6720 bytes
Load file: 'unix.hex', 141140 bytes
Card0 image 'retrobsd.img', 102401 kbytes

2.11 BSD Unix for PIC32, revision G512 build 3:
     Compiled 2025-02-07 by vak@bumba:
     /home/vak/Project/BSD/retrobsd/sys/pic32/max32
cpu: 795F512L 80 MHz, bus 80 MHz
oscillator: HS crystal, PLL div 1:2 mult x20
spi2: pins sdi=RG7/sdo=RG8/sck=RG6
uart1: pins rx=RF2/tx=RF8, interrupts 26/27/28, console
uart2: pins rx=RF4/tx=RF5, interrupts 40/41/42
uart4: pins rx=RD14/tx=RD15, interrupts 67/68/69
sd0: port SPI2, pin cs=RC14
gpio0: portA, pins ii---ii-iiiioiii
gpio1: portB, pins iiiiiiiiiiiiiiii
gpio2: portC, pins i-ii-------iiii-
gpio3: portD, pins --iiiiiiiiiiiiii
gpio4: portE, pins ------iiiiiiiiii
gpio5: portF, pins --ii--------i-ii
gpio6: portG, pins iiii--i-----iiii
adc: 15 channels
pwm: 5 channels
sd0: type I, size 102400 kbytes, speed 10 Mbit/sec
sd0a: partition type b7, sector 2, size 102400 kbytes
sd0b: partition type b8, sector 204802, size 2048 kbytes
sd0c: partition type b7, sector 208898, size 102400 kbytes
phys mem  = 128 kbytes
user mem  = 96 kbytes
root dev  = (0,1)
swap dev  = (0,2)
root size = 102400 kbytes
swap size = 2048 kbytes
/dev/sd0a: 1444 files, 12342 used, 89657 free
Starting daemons: update cron 

2.11 BSD UNIX (pic32) (console)

login: root
Password:
Welcome to RetroBSD!
erase ^?, kill ^U, intr ^C

# date
Sun Jan 24 23:08:07 PST 2016

# df
Filesystem  1K-blocks     Used    Avail Capacity  Mounted on
/dev/sd0a      101999    12345    89654    12%    /

# ps aux
USER       PID NICE SZ TTY  TIME COMMAND
root         0   0   3 ?    0:00 swapper
root         1   0  35 ?    0:00 init - 
root        10   0   7 ?    0:00 update 
root        12   0  54 ?    0:00 cron 
root        13   0  39 0    0:00 -sh 
root        17   0  42 0    0:00 ps aux 

# ls /bin
[            crontab      hostname     pagesize     size         uucico
adb          date         id           passwd       sl           uuclean
adc-demo     dc           iostat       pdc          sleep        uucp
aout         dd           join         picoc        smux         uudecode
apropos      df           kill         portio       sort         uuencode
ar           diff         la           pr           split        uulog
as           diskspeed    last         printenv     strip        uuname
awk          du           lcc          printf       stty         uupoll
basename     echo         lcpp         ps           su           uuq
basic        ed           ld           pwd          sum          uusend
bc           egrep        ln           pwm          sx           uusnap
cal          emg          login        ranlib       sync         uux
calendar     env          lol          rb           sysctl       uuxqt
cat          expr         ls           re           sz           vi
cb           false        mail         renice       tail         vmstat
cc           fgrep        make         renumber     tar          w
chat-server  file         man          retroforth   tee          wall
chflags      find         md5          rev          telnet       wc
chfn         fold         med          rm           test         web-client
chgrp        forth        mesg         rmail        time         web-server
chmod        fstat        mkdir        rmdir        tip          whatis
chpass       glcdtest     more         rx           touch        whereis
chsh         globdump     msec         rz           tr           who
cmp          globread     mv           sb           true         whoami
col          globwrite    nice         scc          tsort        write
comm         grep         nm           scm          tty          xargs
compress     groups       nohup        sed          uname        zcat
cp           head         ntpdate      setty        uncompress
cpp          hostid       od           sh           uniq

# cd /share/examples/asm
# make clean
rm -f *.o ashello echo *.dis *~

# cat ashello.S
/*
 * This is an example of MIPS assembly program for RetroBSD.
 *
 * To compile this program, type:
 *  cc -c ashello.S
 *  ld ashello.o -o ashello
 */
#include <syscall.h>

        .data                               // begin data segment
hello:  .ascii  "Hello, assembly world!\n"  // a string

        .text                               // begin code segment
        .globl  start                       // entry point for ld
start:
        li      $a0, 0                      // arg 1: stdout fd
        la      $a1, hello                  // arg 2: string address
        li      $a2, 23                     // arg 3: string length
        syscall SYS_write                   // call the kernel: write()
        nop                                 // returns here on error
        nop                                 // skips two words on success

        li      $a0, 0                      // arg 1: exit status
        syscall SYS_exit                    // call the kernel: exit()
        // no return

# make ashello
cc  -c ashello.S
ld ashello.o -o ashello

# ./ashello
Hello, assembly world!

# cd /share/examples/c
# make clean
rm -f *.o *~ hello stdarg skeleton primelist primesum test1 test2 test3  gpio adc rain q8 tetris lcd6

# cat hello.c
#include <stdio.h>

int main()
{
    printf ("Hello, C World!\n");
    return 0;
}

# make hello
cc  -o hello  hello.c

# ./hello
Hello, C World!

# halt
killing processes... done
syncing disks... done
halted

Обратите внимание: работают ассемблер и Си компилятор.