From: Christopher Head Date: Sat, 27 Oct 2018 00:05:00 +0000 (-0700) Subject: target/stm32h7x: Fix documentation of reset_config X-Git-Tag: v0.11.0-rc1~955 X-Git-Url: https://review.openocd.org/gitweb?p=openocd.git;a=commitdiff_plain;h=5ea55a39753aa570c45cffbdb7c39f6f9a9bb359;ds=inline target/stm32h7x: Fix documentation of reset_config The stm32h7x.cfg does not specify connect_assert_srst or connect_deassert_srst in its reset_config. The comment claims that it will therefore connect in reset. However, per the manual, the default configuration is actually connect_deassert_srst, not connect_assert_srst. In actual fact, connect_assert_srst does not work on the STM32H7 because, while SRST is asserted, everything on the AXI bus is inaccessible. The CPU core is accessible, but since the examine-end event handler also pokes at the DBGMCU peripheral, that will fail in connect_assert_srst mode. So using connect_deassert_srst is appropriate, so fix the comment accordingly. Change-Id: If3e32e871fb19cc61183bdf911b7c5efd80b62e2 Signed-off-by: Christopher Head Reviewed-on: http://openocd.zylin.com/4741 Tested-by: jenkins Reviewed-by: Tomas Vanek --- diff --git a/tcl/target/stm32h7x.cfg b/tcl/target/stm32h7x.cfg index c9aec76126..0bfc43dfd4 100644 --- a/tcl/target/stm32h7x.cfg +++ b/tcl/target/stm32h7x.cfg @@ -56,7 +56,17 @@ if {[using_jtag]} { jtag_ntrst_delay 100 } -# use hardware reset, connect under reset +# use hardware reset +# +# The STM32H7 does not support connect_assert_srst mode because the AXI is +# unavailable while SRST is asserted, and that is used to access the DBGMCU +# component at 0x5C001000 in the examine-end event handler. +# +# It is possible to access the DBGMCU component at 0xE00E1000 via AP2 instead +# of the default AP0, and that works with SRST asserted; however, nonzero AP +# usage does not work with HLA, so is not done by default. That change could be +# made in a local configuration file if connect_assert_srst mode is needed for +# a specific application and a non-HLA adapter is in use. reset_config srst_only srst_nogate if {![using_hla]} {