Software breakpoints - debugging e5500 on T1024 based board

[saxomaniac]

We have a custom board based on the T1024 with two e5500 cores on it. I just recently built a Linux for this machine with yocto. So far we've managed to get it up and running. Now I wanted to check whether the debugger works and I created a toy program in order to cross-compile it and have it debugged on the board. So I tried to use gdb on the machine itself, this didn't work, it seems gdb has a bug on ppc machines since it mixes up the ppccommon and ppccommon64 architectures. So I tried with gdbserver and afterwards with lldb-server.

This is what I get when I debug an application with lldb (connecting to lldb-server) and I try to set a breakpoint:

GDB

(gdb) target remote testbox:1234
Remote debugging using testbox:1234
Reading /home/root/foo from remote target...
warning: File transfers from remote targets can be slow. Use "set sysroot" to access files locally instead.
warning: Selected architecture powerpc:common64 is not compatible with reported target architecture powerpc:common
warning: Architecture of file not recognized.
Reading /home/root/foo from remote target...
Reading symbols from target:/home/root/foo...
Reading /lib64/ld64.so.1 from remote target...
warning: Unable to find dynamic linker breakpoint function.
GDB will be unable to debug shared library initializers
and track explicitly loaded dynamic code.
0xf7fce8d0 in ?? ()
(gdb) b main
warning: could not convert 'main' from the host encoding (UTF-8) to UTF-32.
This normally should not happen, please file a bug report.
Breakpoint 1 at 0x1814: file /home/david/tests/vrag-linux/src/foo.cpp, line 15.
(gdb) c
Continuing.
Warning:
Cannot insert breakpoint 1.
Cannot access memory at address 0x1814
Cannot insert breakpoint -1.
Cannot access memory at address 0x1fb28

Command aborted.
(gdb) hbreak main
Note: breakpoint 1 also set at pc 0x1814.
Hardware assisted breakpoint 2 at 0x1814: file /home/david/tests/vrag-linux/src/foo.cpp, line 15.
(gdb) c
Continuing.
Warning:
Cannot insert breakpoint 1.
Cannot access memory at address 0x1814
Cannot insert hardware breakpoint 2.
Cannot insert breakpoint -1.
Cannot access memory at address 0x1fb28
Could not insert hardware breakpoints:
You may have requested too many hardware breakpoints/watchpoints.

Command aborted.
(gdb)

LLDB

(lldb) platform select remote-linux
  Platform: remote-linux
 Connected: no
(lldb) platform connect connect://testbox:1234
  Platform: remote-linux
    Triple: powerpc64-vrag-linux
OS Version: 6.4.0 (6.4.0-rc6-rt8-vrag-00002-g308420dc5151)
  Hostname: bf133
 Connected: yes
WorkingDir: /home/root
    Kernel: #1 SMP PREEMPT_RT Sun Jun 11 21:35:30 UTC 2023
(lldb) file build/src/foo
Current executable set to '/home/david/tests/vrag-linux/build/src/foo' (powerpc64).
(lldb) b main
Breakpoint 1: 2 locations.
(lldb) r
Process 461 launched: '/home/david/tests/vrag-linux/build/src/foo' (powerpc64)
Hi there from main
Hi there from foo
0123456789:;<=>?@ABCDEFGHIJKLMNO
Process 461 exited with status = 0 (0x00000000)
(lldb)

When I use the debugger protocol with codelldb to connect to lldb-server I get the following output (nvim-dap):

[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    category = "console",
    output = "  Platform: remote-linux\n Connected: no\n\n"
  },
  event = "output",
  seq = 4,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    category = "console",
    output = "  Platform: remote-linux\n    Triple: powerpc64-vrag-linux\nOS Version: 6.4.0 (6.4.0-rc6-rt8-vrag-00002-g308420dc5151)\n  Hostname: bf133\n Connected: yes\nWorkingDir: /home/root\n    Kernel: #1 SMP PREEMPT_RT Sun Jun 11 21:35:30 UTC 2023\n\n"
  },
  event = "output",
  seq = 5,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  event = "initialized",
  seq = 6,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:1672 ]	"request"	{
  arguments = {
    breakpoints = { {
        line = 16
      } },
    lines = { 16 },
    source = {
      name = "foo.cpp",
      path = "/home/david/tests/vrag-linux/src/foo.cpp"
    },
    sourceModified = false
  },
  command = "setBreakpoints",
  seq = 2,
  type = "request"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    module = {
      addressRange = "FFFFFFFFFFFFFFFF",
      id = "FFFFFFFFFFFFFFFF",
      name = "foo",
      path = "/home/david/tests/vrag-linux/build/src/foo",
      symbolFilePath = "/home/david/tests/vrag-linux/build/src/foo",
      symbolStatus = "Symbols loaded."
    },
    reason = "new"
  },
  event = "module",
  seq = 7,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    breakpoints = { {
        id = 1,
        line = 16,
        message = "Resolved locations: 0",
        verified = true
      } }
  },
  command = "setBreakpoints",
  request_seq = 2,
  seq = 8,
  success = true,
  type = "response"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:1672 ]	"request"	{
  arguments = {
    filters = { "cpp_throw" }
  },
  command = "setExceptionBreakpoints",
  seq = 3,
  type = "request"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  command = "setExceptionBreakpoints",
  request_seq = 3,
  seq = 9,
  success = true,
  type = "response"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:1672 ]	"request"	{
  command = "configurationDone",
  seq = 4,
  type = "request"
}
[ DEBUG ] 2023-09-28T12:12:28Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    category = "console",
    output = "Launching: /home/david/tests/vrag-linux/build/src/foo\n"
  },
  event = "output",
  seq = 10,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    category = "console",
    output = "Launched process 477\n"
  },
  event = "output",
  seq = 11,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  command = "launch",
  request_seq = 1,
  seq = 12,
  success = true,
  type = "response"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  command = "configurationDone",
  request_seq = 4,
  seq = 13,
  success = true,
  type = "response"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    module = {
      addressRange = "3FFFF7F9E000",
      id = "3FFFF7F9E000",
      name = "ld64.so.1",
      path = "/home/david/.lldb/module_cache/remote-linux/.cache/B9E2FC14-1A0D-3AA5-FF06-162D87714892-BBEEF361/ld64.so.1",
      symbolFilePath = "/home/david/.lldb/module_cache/remote-linux/.cache/B9E2FC14-1A0D-3AA5-FF06-162D87714892-BBEEF361/ld64.so.1",
      symbolStatus = "Symbols loaded."
    },
    reason = "new"
  },
  event = "module",
  seq = 14,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    module = {
      addressRange = "3FFFF7FF2000",
      id = "3FFFF7FF2000",
      name = "[vdso]",
      path = "[vdso]",
      symbolStatus = "Symbols not found"
    },
    reason = "new"
  },
  event = "module",
  seq = 15,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    module = {
      addressRange = "FFFFFFFFFFFE19B8",
      id = "FFFFFFFFFFFE19B8",
      name = "foo",
      path = "/home/david/tests/vrag-linux/build/src/foo",
      symbolFilePath = "/home/david/tests/vrag-linux/build/src/foo",
      symbolStatus = "Symbols loaded."
    },
    reason = "new"
  },
  event = "module",
  seq = 16,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    allThreadsContinued = true,
    threadId = 477
  },
  event = "continued",
  seq = 17,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    category = "stdout",
    output = "Hi there from main\r\nHi there from foo\r\n0123456789:;<=>?@ABCDEFGHIJKLMNO\r\n"
  },
  event = "output",
  seq = 18,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    category = "console",
    output = "Process exited with code 0.\n"
  },
  event = "output",
  seq = 19,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = {
    exitCode = 0
  },
  event = "exited",
  seq = 20,
  type = "event"
}
[ DEBUG ] 2023-09-28T12:12:29Z+0200 ] ...avid/.local/share/nvim/lazy/nvim-dap/lua/dap/session.lua:950 ]	1	{
  body = vim.empty_dict(),
  event = "terminated",
  seq = 21,
  type = "event"
}

GDB stops, lldb continues but does not stop at any breakpoint. The DAP log shows that the breakpoint could not be inserted (message = "Resolved locations: 0").

I have a slight feeling that there is something wrong with the MSR - or am I mistaken - is it that there is no software debugging capability on this product? I have searched for a MSR or SPR description of the E5500 but I could not find any. Now I am really confused.

I would be very happy if someone could bring some light into this issue.

[LFGP]

it is necessary to rebuilt it and chose the correct architecture for your objetives, please try to resolve the warning showed in the log before debug anything.

on the other hand, We use Codewarrior in order to develop a debug ( it's necessary to use a CW TAP ) 

[LFGP]

Could you please confirm if you are running GDBserver in one side and in the other side you are running GDB, Even you can use CodeWario IDE to develop a debug into the target.

[saxomaniac]

Yes, I am running gdbserver on the target - I have tried connecting to gdbserver, lldb-server, launching gdb directly on the target (does not work at all though) and using lldb directly to debug. All the same, the same problems, no breakpoints. And there are debug symbols compiled in and I turned off optimizations.

It's an e5500.