Invalid ELF file error in CFE bootloader

Question

I have a Broadcom switch board with a MPC8548E PowerPC CPU on it. I have created a toolchain for this very CPU using crosstool-ng. When I try to load the compiled binary using the CFE> boot loader on this board with the command load -elf 10.13.51.131:main, I get the following output:

CFE> load -elf 10.13.51.131:main
Loader:elf Filesys:tftp Dev:eth0 File:10.13.51.131:main Options:(null)
Loading: Warning: negative seek on tftp file attempted
Failed.
Could not load 10.13.51.131:main: Invalid ELF file
*** command status = -16

Why would it say Invalid ELF file? readelf -h shows me the following info:

$ readelf -h main
ELF Header:
  Magic:   7f 45 4c 46 01 02 01 00 00 00 00 00 00 00 00 00
  Class:                             ELF32
  Data:                              2's complement, big endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              EXEC (Executable file)
  Machine:                           PowerPC
  Version:                           0x1
  Entry point address:               0x100002c8
  Start of program headers:          52 (bytes into file)
  Start of section headers:          3972 (bytes into file)
  Flags:                             0x0
  Size of this header:               52 (bytes)
  Size of program headers:           32 (bytes)
  Number of program headers:         7
  Size of section headers:           40 (bytes)
  Number of section headers:         28
  Section header string table index: 25

How do I get the ELF file loaded, I don't even want to run anything yet, it first needs to accept the ELF. I have another ELF that's (supposedly) ready to run compiled with VxWorks but I get the same error using that one, too.

This for a Broadcom reference board for the switch BCM956440.

Answer 1

It looks like your file isn't being transferred (via tftp) correctly, leading to errors when the file is to be parsed as ELF.

Perhaps try running a packet capture on the tftp server, to inspect the traffic between booloader and server. Try something like this on the tftp server:

tcpdump -s 2048 -w tftp.pcap -i <interface> udp port tftp

- then open the resulting tftp.pcap file with wireshark.