On 05/03/12 08:30, Tomas Frydrych wrote: > On 04/03/12 19:37, John Dallaway wrote: >> However, this success was achieved using arm-eabi-gdb 6.8.50.20080706. >> There does appear to be an issue with the length of the 'g' packet when >> using the new arm-eabi-gdb 7.3.1: >> >>> (gdb) tar rem /dev/ttyS0 >>> Remote debugging using /dev/ttyS0 >>> Remote 'g' packet reply is too long: >>> e14e000810000000000000001000000000000000000000000000000000000000000000000000000000000000fccf0d6800000000e8cf0d6895680008e24e00080000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000021 >>> (gdb) >> >> We will need to look into why the packet length has apparently changed >> for Cortex-M targets. I can connect to an ARM7 target using the new GDB >> without problem. > > This is a mismatch between the number of registers a gdb server reports > and the number that gdb expects for the given architecture. In this case > too many registers are being reported. IIRC, there should be 8 hex > digits for a register, so the above string seems to represent 42 > registers instead of the 21 that Cortex-M has. Looks like a bug in the > monitor stub code, or perhaps a work around for something broken in > older toolchains?
Done bit further digging around the sources, hal/cortexm/arch/.../cortexm_stub.h:64 defines 16 gpr, 8 fp or 12 bytes each and 2 ps registers; this adds up to the 336 bytes of the above output. Tomas > > Tomas
