Those few targets that have problems with fast_memory_access or dcc_downloads must add event handlers to the reset sequence to deal with this. The typical example are CPUs that run at kHz clocks.
Signed-off-by: Øyvind Harboe <oyvind.har...@zylin.com> --- doc/openocd.texi | 15 ++++++++++----- src/target/arm7_9_common.c | 8 ++++---- 2 files changed, 14 insertions(+), 9 deletions(-) diff --git a/doc/openocd.texi b/doc/openocd.texi index ea30092..43ea0d8 100644 --- a/doc/openocd.texi +++ b/doc/openocd.texi @@ -5642,18 +5642,23 @@ including ARM9TDMI, ARM920T, and ARM926EJ-S. @deffn Command {arm7_9 dcc_downloads} (@option{enable}|@option{disable}) @cindex DCC -Control the use of the debug communications channel (DCC) to write larger (>128 byte) +Enabled by default. Control the use of the debug communications channel (DCC) to write larger (>128 byte) amounts of memory. DCC downloads offer a huge speed increase, but might be -unsafe, especially with targets running at very low speeds. This command was introduced -with OpenOCD rev. 60, and requires a few bytes of working area. +unsafe, especially with targets running at very low speeds. This command requires +a few bytes of working area. This is implemented as an open loop where +OpenOCD pours data into the target. If the target is not able to keep +up, then OpenOCD will print an error message after the transfer +from OpenOCD is complete. @end deffn @anchor{arm7_9 fast_memory_access} @deffn Command {arm7_9 fast_memory_access} (@option{enable}|@option{disable}) -Enable or disable memory writes and reads that don't check completion of +Enabled by default. Enable or disable memory writes and reads that don't check completion of the operation. This provides a huge speed increase, especially with USB JTAG cables (FT2232), but might be unsafe if used with targets running at very low -speeds, like the 32kHz startup clock of an AT91RM9200. +speeds, like the 32kHz startup clock of an AT91RM9200. Targets that +require such low speeds during reset, will have to add reset event +handlers to turn this option off temporarily. @end deffn @subsection ARM720T specific commands diff --git a/src/target/arm7_9_common.c b/src/target/arm7_9_common.c index b5553cd..5438855 100644 --- a/src/target/arm7_9_common.c +++ b/src/target/arm7_9_common.c @@ -2828,8 +2828,8 @@ int arm7_9_init_arch_info(struct target *target, struct arm7_9_common *arm7_9) arm7_9->wp_available_max = 2; - arm7_9->fast_memory_access = false; - arm7_9->dcc_downloads = false; + arm7_9->fast_memory_access = true; + arm7_9->dcc_downloads = true; armv4_5->arch_info = arm7_9; armv4_5->read_core_reg = arm7_9_read_core_reg; @@ -2858,14 +2858,14 @@ static const struct command_registration arm7_9_any_command_handlers[] = { .mode = COMMAND_ANY, .usage = "<enable|disable>", .help = "use fast memory accesses instead of slower " - "but potentially safer accesses", + "but potentially safer accesses. Enabled by default.", }, { "dcc_downloads", .handler = &handle_arm7_9_dcc_downloads_command, .mode = COMMAND_ANY, .usage = "<enable | disable>", - .help = "use DCC downloads for larger memory writes", + .help = "use DCC downloads for larger memory writes. Enabled by default.", }, COMMAND_REGISTRATION_DONE }; -- 1.6.3.3 _______________________________________________ Openocd-development mailing list Openocd-development@lists.berlios.de https://lists.berlios.de/mailman/listinfo/openocd-development