Re: [RFC PATCH 00/34] The rest of the x86_64-gnu port

[Sergey Bugaev]

On Tue, Mar 21, 2023 at 2:04 PM Sergey Bugaev <bugaevc@gmail.com> wrote:
> It seems to parse the bootscript correctly. It starts the initial
> thread, which loads the ELF and then hangs right here (on printf???):
>
> <snip>
>
> Does that ring any bells?

Maybe this will shed some light:

(gdb) s
charput (pos=3840, ch=116 't', chattr=7 '\a') at ../i386/i386at/kd.c:2591
2591 *(vid_start + pos) = ch;
(gdb) bt
#0  charput (pos=3840, ch=116 't', chattr=7 '\a') at ../i386/i386at/kd.c:2591
#1  0xffffffff8100d4c0 in kd_putc (ch=<optimized out>) at
../i386/i386at/kd.c:1291
#2  0xffffffff8100f9a5 in kd_putc_esc (c=<optimized out>) at
../i386/i386at/kd.c:1240
#3  kdcnputc (dev=<optimized out>, c=<optimized out>) at
../i386/i386at/kd.c:2938
#4  0xffffffff8102c888 in cnputc (c=116 't') at ../device/cons.c:163
#5  0xffffffff81014365 in _doprnt (fmt=fmt@entry=0xffffffff81066a56
"task loaded:", argp=argp@entry=0xffffffffbf112f20,
putc=0xffffffff8102cb30 <cnputc>,
    radix=radix@entry=16, putc_arg=putc_arg@entry=0) at ../kern/printf.c:177
#6  0xffffffff81015252 in vprintf (listp=0xffffffffbf112f20,
fmt=0xffffffff81066a56 "task loaded:") at ../kern/printf.c:502
#7  printf (fmt=fmt@entry=0xffffffff81066a56 "task loaded:") at
../kern/printf.c:511
#8  0xffffffff8104ad9b in user_bootstrap () at ../kern/bootstrap.c:815
#9  0x0000000000000000 in ?? ()
(gdb) p vid_start
$67 = (u_char *) 0xffffffff800b8000 <error: Cannot access memory at
address 0xffffffff800b8000>
(gdb) p *vid_start
Cannot access memory at address 0xffffffff800b8000
(gdb) info mem
Using memory regions provided by the target.
There are no memory regions defined.
(gdb) s
t_page_fault () at ../x86_64/locore.S:442
442 pushq $(T_PAGE_FAULT) /* mark a page fault trap */
(gdb) bt
#0  t_page_fault () at ../x86_64/locore.S:442
#1  0x0000000000000002 in ?? ()
#2  0xffffffff8100c8eb in charput (pos=3840, ch=116 't', chattr=7
'\a') at ../i386/i386at/kd.c:2591
#3  0x0000000000000008 in ?? ()
#4  0x0000000000000202 in ?? ()
#5  0xffffffffbf112e20 in ?? ()
#6  0x0000000000000010 in ?? ()
#7  0xffffffff8100d4c0 in kd_putc (ch=<optimized out>) at
../i386/i386at/kd.c:1291
#8  0xffffffff8100f9a5 in kd_putc_esc (c=<optimized out>) at
../i386/i386at/kd.c:1240
#9  kdcnputc (dev=<optimized out>, c=<optimized out>) at
../i386/i386at/kd.c:2938
#10 0xffffffff8102c888 in cnputc (c=116 't') at ../device/cons.c:163
#11 0xffffffff81014365 in _doprnt (fmt=fmt@entry=0xffffffff81066a56
"task loaded:", argp=argp@entry=0xffffffffbf112f20,
putc=0xffffffff8102cb30 <cnputc>,
    radix=radix@entry=16, putc_arg=putc_arg@entry=0) at ../kern/printf.c:177
#12 0xffffffff81015252 in vprintf (listp=0xffffffffbf112f20,
fmt=0xffffffff81066a56 "task loaded:") at ../kern/printf.c:502
#13 printf (fmt=fmt@entry=0xffffffff81066a56 "task loaded:") at
../kern/printf.c:511
#14 0xffffffff8104ad9b in user_bootstrap () at ../kern/bootstrap.c:815
#15 0x0000000000000000 in ?? ()
(gdb)

Sergey