[H8-uclinux-port] /bin/init process execution and busybox console

[Aleix B. i B. <a....@ca...>]

Dear all, I've some problems executing uclinux (linux-2.6.7 + uclinux +
h8300 port) using gdb debugger.

It looks like if there's no kernel initialization problem:
  - MTD initialization (RAM)
  - FS (romfs) initialization
  - console registration
  - sys_open /dev/console

NOTE: I'm using rootimage from uclinux-h8.sourceforge.jp with some /dev
modifications

crw-------    1 root     root       5,   1 gen  1  1970 console
crw-------    1 root     root       4,   0 gen  1  1970 tty0
crw-------    1 root     root       4,  64 gen  1  1970 ttySC0
crw-------    1 root     root       4,  65 gen  1  1970 ttySC1


but it fails (or at least it looks like it fail) as there's no ouput,
when trying to execute /bin/init, just like idle task?=BF. I'm not sure if
/bin/init is running but gdb can't trace that process that way, or if
there's really a problem on kernel execve (-> syscall).


....
    if (execute_command)
             run_init_process(execute_command);

     run_init_process("/sbin/init");  -> fails (OK rootimage->/bin/init)
     run_init_process("/etc/init");   -> fails (OK rootimage->/bin/init)
     run_init_process("/bin/init");   -> OK (MTD OK, romfs OK)
     run_init_process("/bin/sh");

      panic("No init found.  Try passing init=3D option to kernel.");
....


Breakpoint 5, sys_execve (name=3D0x5bb000 "/bin/init", argv=3D0x202004,=20
    envp=3D0x20202c, dummy=3D703605) at arch/h8300/kernel/process.c:256
256             error =3D do_execve(filename, argv, envp, regs);
3: error =3D 6008832
(gdb) n
257             putname(filename);
3: error =3D 0
(gdb)=20


GDB should show some init starting message (perhaps not the same as
busybox code below and rootimage are extracted from different busybox
versions)

extern int init_main(int argc, char **argv)
{

..=20
  /* Hello world */
  message(MAYBE_CONSOLE | LOG, "init started:  %s",
bb_msg_full_version);
...

}

Perhaps bad busybox console initialization ?


I've no clear idea about gdb execution and the way console (struct
console) gdb_console, registred as gdb_con, is used by debugger; the
same with /dev/ttySC* or /dev/ttyS*


I just insert gdb vmlinux debugging output and attach .config file:

(gdb) target sim
SCI0 =3D /dev/pts/9
Connected to the simulator.

(gdb) load
Loading section .vectors, size 0x100 vma 0x0
Loading section .text, size 0xb4410 vma 0x100
Loading section .data, size 0xfc40 vma 0x200000
Loading section .romfs, size 0xc400 vma 0x218a98
Start address 0x200
Transfer rate: 6826624 bits in <1 sec.

(gdb) r
Starting program: /home/usuari/linux-2.6.7/vmlinux=20
Linux version 2.6.7-uc0 (usuari@debian) (gcc version 3.1.1) #77 Mon Sep
6 08:38:01 CEST 2004


uClinux H8/300H
Target Hardware: generic
Flat model support (C) 1998,1999 Kenneth Albanowski, D. Jeff Dionne
H8/300 series support by Yoshinori Sato <ys...@us...>
On node 0 totalpages: 1536
  DMA zone: 0 pages, LIFO batch:1
  Normal zone: 1536 pages, LIFO batch:1
  HighMem zone: 0 pages, LIFO batch:1
Built 1 zonelists
Kernel command line: console=3DttySC0,38400n81
PID hash table entries: 16 (order 4: 128 bytes)
Linux version 2.6.7-uc0 (usuari@debian) (gcc version 3.1.1) #77 Mon Sep
6 08:38:01 CEST 2004


uClinux H8/300H
Target Hardware: generic
Flat model support (C) 1998,1999 Kenneth Albanowski, D. Jeff Dionne
H8/300 series support by Yoshinori Sato <ys...@us...>
On node 0 totalpages: 1536
  DMA zone: 0 pages, LIFO batch:1
  Normal zone: 1536 pages, LIFO batch:1
  HighMem zone: 0 pages, LIFO batch:1
Built 1 zonelists
Kernel command line: console=3DttySC0,38400n81
PID hash table entries: 16 (order 4: 128 bytes)
Memory available: 3860k/999k RAM, 0k/0k ROM (720k kernel code, 98k data)
Calibrating delay loop... 5.00 BogoMIPS
Dentry cache hash table entries: 1024 (order: 0, 4096 bytes)
Inode-cache hash table entries: 1024 (order: 0, 4096 bytes)
Mount-cache hash table entries: 512 (order: 0, 4096 bytes)
Linux NoNET1.0 for Linux 2.6
SuperH SCI(F) driver initialized
ttySC0 at MMIO 0xffffb0 (irq =3D 54) is a sci
ttySC1 at MMIO 0xffffb8 (irq =3D 58) is a sci
ttySC2 at MMIO 0xffffc0 (irq =3D 62) is a sci
Using anticipatory io scheduler
uclinux[mtd]: RAM probe address=3D0x218a98 size=3D0xd000
Creating 1 MTD partitions on "RAM":
0x00000000-0x0000d000 : "ROMfs"
uclinux[mtd]: set ROMfs to be root filesystem
VFS: Mounted root (romfs filesystem) readonly.

Program received signal SIGSEGV, Segmentation fault.
0x0006c5a4 in L1a5 () at lib/radix-tree.c:756
756     }
(gdb)=20


Regards,


--=20
Aleix Badia i Bosch
a....@ca...