I work at Broadcom and I was asked to see if I can get running our new chip with openwrt (at this point just a proof-of-concept). I substituted the tooolchain with our own and pointed to our own kernel tree (all done through make menuconfig).  I did not change anything else in the openwrt config - all default packages. The build succeeded and I have a vmlinux, vmllinux-initramfs as well as rootfs.tar.gz

Unfortunately my board fails during the boot process fails with the following error:
[    3.966865] VFS: Mounted root (ubifs filesystem) readonly on device 0:12.
[    3.975124] devtmpfs: mounted
[    3.978231] Freeing unused kernel memory: 264K (c0745000 - c0787000)
[    3.996134] Kernel panic - not syncing: No working init found.  Try passing init= option to kernel. See Linux Documentation/init.txt for guidance.
[    4.009279] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.13-1.2pre_rgu-1.5.00 #10
[    4.016963] [<c00149f8>] (unwind_backtrace) from [<c0010f08>] (show_stack+0x10/0x14)
[    4.024721] [<c0010f08>] (show_stack) from [<c056c3f8>] (dump_stack+0x80/0x90)
[    4.031955] [<c056c3f8>] (dump_stack) from [<c056a6f8>] (panic+0xa4/0x1f0)
[    4.038840] [<c056a6f8>] (panic) from [<c0567510>] (cpu_die+0x0/0x80)
[    4.045290] [<c0567510>] (cpu_die) from [<00000000>] (  (null))

I tried booting using vmlinux-initramfs and also tried vmlinux with the rootfs from the flash. The same error in both cases.

To see if the openwrt rootfs produced by the build is good I booted my board with the rootfs produced by the regular Broadcom build and mounted the openwrt rootfs. The mount succeeds and I can see the expected directory structure but any attempt to execute any of the binaries in the openwrt rootfs tree results in the following error:

# /mnt/flash/bin/busybox
sh: /mnt/flash/bin/busybox: No such file or directory

With strace:

# strace /mnt/flash/bin/busybox
execve("/mnt/flash/bin/busybox", ["/mnt/flash/bin/busybox"], [/* 9 vars */]) = -1 ENOENT (No such file or directory)
dup(2)                                  = 3
fcntl64(3, F_GETFL)                     = 0x20002 (flags O_RDWR|O_LARGEFILE)
fstat64(3, {st_mode=S_IFCHR|0600, st_rdev=makedev(4, 64), ...}) = 0
ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B115200 opost isig icanon echo ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb6f2b000
_llseek(3, 0, 0xbeae8a08, SEEK_CUR)     = -1 ESPIPE (Illegal seek)
write(3, "strace: exec: No such file or di"..., 40strace: exec: No such file or directory
) = 40
close(3)                                = 0
munmap(0xb6f2b000, 4096)                = 0
exit_group(1)                           = ?

It seems to me that the two problems (boot and executing mounted binary) are related but I am not sure what causes them.

Both Broadcom built and openwrt built busybox binaries seem to be compiled correctly:

# file /bin/busybox
/bin/busybox: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.16, stripped

# file /mnt/flash/bin/busybox
/mnt/flash/bin/busybox: ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.16, stripped

Any help appreciated.

Looks like it does not find the dynamic linker (ld.so). Try executing the binaries after a chroot.

Unfortunately I am unable to chroot:

# chroot /mnt/flash
chroot: can't execute '/bin/sh': No such file or directory
#
#
#
# strace chroot /mnt/flash
execve("/sbin/chroot", ["chroot", "/mnt/flash"], [/* 11 vars */]) = 0
brk(0)                                  = 0x78000
uname({sys="Linux", node="(none)", ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb6ff8000
access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/v7l/neon/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls/v7l/neon/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/v7l/neon/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls/v7l/neon", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/v7l/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls/v7l/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/v7l/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls/v7l", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/neon/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls/neon/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/neon/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls/neon", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/tls/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/tls", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/v7l/neon/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/v7l/neon/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/v7l/neon/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/v7l/neon", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/v7l/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/v7l/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/v7l/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/v7l", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/neon/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/neon/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/neon/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/neon", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/vfp/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = -1 ENOENT (No such file or directory)
stat64("/mnt/flash/lib/vfp", 0xbeb444e8) = -1 ENOENT (No such file or directory)
open("/mnt/flash/lib/libcrypt.so.1", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0@\t\0\0004\0\0\0"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=30400, ...}) = 0
mmap2(NULL, 254328, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb6f95000
mprotect(0xb6f9c000, 61440, PROT_NONE)  = 0
mmap2(0xb6fab000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x6) = 0xb6fab000
mmap2(0xb6fad000, 156024, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb6fad000
close(3)                                = 0
open("/mnt/flash/lib/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0(\0\1\0\0\0\rw\1\0004\0\0\0"..., 512) = 512
fstat64(3, {st_mode=S_IFREG|0755, st_size=902844, ...}) = 0
mmap2(NULL, 972136, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb6ea7000
mprotect(0xb6f7f000, 65536, PROT_NONE)  = 0
mmap2(0xb6f8f000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0xd8) = 0xb6f8f000
mmap2(0xb6f92000, 9576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb6f92000
close(3)                                = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb6ff7000
set_tls(0xb6ff76d0, 0xb6ffb058, 0xb6ff7db8, 0xb6ff76d0, 0xb6ffb058) = 0
mprotect(0xb6f8f000, 8192, PROT_READ)   = 0
mprotect(0xb6fab000, 4096, PROT_READ)   = 0
mprotect(0xb6ffa000, 4096, PROT_READ)   = 0
getuid32()                              = 0
chroot("/mnt/flash")                    = 0
chdir("/")                              = 0
execve("/bin/sh", ["/bin/sh", "-i"], [/* 11 vars */]) = -1 ENOENT (No such file or directory)
brk(0)                                  = 0x78000
brk(0x99000)                            = 0x99000
write(2, "chroot: can't execute '/bin/sh':"..., 59chroot: can't execute '/bin/sh': No such file or directory
) = 59
exit_group(127)                         = ?
#

Hmmm..... If I invoke the binary using dynamic linker directly everything works. What does it mean?

# /lib/ld-2.18-2013.10.so /mnt/flash/bin/busybox
BusyBox v1.22.1 (2015-03-04 10:34:46 EST) multi-call binary.
BusyBox is copyrighted by many authors between 1998-2012.
Licensed under GPLv2. See source distribution for detailed
copyright notices.

Usage: busybox [function [arguments]...]
   or: busybox --list
   or: function [arguments]...

    BusyBox is a multi-call binary that combines many common Unix
    utilities into a single executable.  Most people will create a
    link to busybox for each function they wish to use and BusyBox
    will act like whatever it was invoked as.

Currently defined functions:
    [, [[, arping, ash, awk, basename, brctl, bunzip2, bzcat, cat, chgrp,
    chmod, chown, chroot, clear, cmp, cp, crond, crontab, cut, date, dd,
    devmem, df, dirname, dmesg, du, echo, egrep, env, expr, false, fgrep,
    find, free, fsync, grep, gunzip, gzip, halt, head, hexdump, hostid,
    hwclock, id, ifconfig, kill, killall, less, ln, lock, logger, ls,
    md5sum, mkdir, mkfifo, mknod, mkswap, mktemp, mount, mv, nc, netmsg,
    netstat, nice, nslookup, ntpd, passwd, pgrep, pidof, ping, ping6,
    pivot_root, poweroff, printf, ps, pwd, readlink, reboot, reset, rm,
    rmdir, route, sed, seq, sh, sleep, sort, start-stop-daemon, strings,
    switch_root, sync, sysctl, tail, tar, tee, telnet, telnetd, test, time,
    top, touch, tr, traceroute, true, udhcpc, umount, uname, uniq, uptime,
    vconfig, vi, wc, wget, which, xargs, yes, zcat

# /mnt/flash/lib/ld-2.18-2013.10.so /mnt/flash/bin/busybox
BusyBox v1.22.1 (2015-03-04 10:34:46 EST) multi-call binary.
BusyBox is copyrighted by many authors between 1998-2012.
Licensed under GPLv2. See source distribution for detailed
copyright notices.

Usage: busybox [function [arguments]...]
   or: busybox --list
   or: function [arguments]...

    BusyBox is a multi-call binary that combines many common Unix
    utilities into a single executable.  Most people will create a
    link to busybox for each function they wish to use and BusyBox
    will act like whatever it was invoked as.

Currently defined functions:
    [, [[, arping, ash, awk, basename, brctl, bunzip2, bzcat, cat, chgrp,
    chmod, chown, chroot, clear, cmp, cp, crond, crontab, cut, date, dd,
    devmem, df, dirname, dmesg, du, echo, egrep, env, expr, false, fgrep,
    find, free, fsync, grep, gunzip, gzip, halt, head, hexdump, hostid,
    hwclock, id, ifconfig, kill, killall, less, ln, lock, logger, ls,
    md5sum, mkdir, mkfifo, mknod, mkswap, mktemp, mount, mv, nc, netmsg,
    netstat, nice, nslookup, ntpd, passwd, pgrep, pidof, ping, ping6,
    pivot_root, poweroff, printf, ps, pwd, readlink, reboot, reset, rm,
    rmdir, route, sed, seq, sh, sleep, sort, start-stop-daemon, strings,
    switch_root, sync, sysctl, tail, tar, tee, telnet, telnetd, test, time,
    top, touch, tr, traceroute, true, udhcpc, umount, uname, uniq, uptime,
    vconfig, vi, wc, wget, which, xargs, yes, zcat

#

OK. I think I understand the problem now. The section called ".interp" of each elf file contains the path to the dynamic linker. This path was added during build time. In my case:

# objdump -s -j .interp bin/busybox

bin/busybox:     file format elf32-little

Contents of section .interp:
10134 2f6c6962 2f6c642d 75436c69 62632e73  /lib/ld-uClibc.s
10144 6f2e3000                             o.0.           

However,  /lib/ld-uClibc.so is not present in my rootfs. Now I have to figure out how to set it properly during build.

I confirmed the problem by creating a soft link:

/lib/ld-uClibc.so.0 -> ld-2.18-2013.10.so

and executing /mn/flash/bin/busybox again.

Hi,
I would like to know the difference between this tow commandline:
  make -C feeds/my_projet/new_package/compile
  make package/new_package

please help me

In general "make -C" causes make to switch to the directory specified after "-C" and use the make file in this directory.

Is this question related to this thread somehow? If not it should have been posted as a new thread...