0cf38dc8c8
Add a new function backtrace_str() that returns a condensed backtrace string containing function names and line numbers separated by " <-". For example: "func_a:123 <-func_b:456 <-func_c:789" This is useful for logging and debugging where a compact representation of the call stack is needed. The depth is controlled by the new CONFIG_BACKTRACE_DEPTH option (default 3). Co-developed-by: Claude <noreply@anthropic.com> Signed-off-by: Simon Glass <simon.glass@canonical.com>