Re: [OpenOCD-user] Advice on Snapdragon 820

[Matthias W. <mat...@we...>]

On Thursday 05 January 2017 23:21:36 Sergei Antonov wrote:
> The first time I try to connect after rebooting the device, behavior
> is different (though examination fails anyway):
> 
> Debug: 206 35 arm_adi_v5.c:603 dap_dp_init():
> Debug: 207 35 arm_adi_v5.c:636 dap_dp_init(): DAP: wait CDBGPWRUPACK
> Debug: 208 35 arm_adi_v5.h:432 dap_dp_poll_register(): DAP: poll 4,
> mask 0x20000000, value 0x20000000
> Debug: 209 136 arm_adi_v5.c:789 dap_find_ap(): Found APB-AP at AP
> index: 1 (IDR=0x44770002)
> Debug: 210 174 arm_adi_v5.c:716 mem_ap_init(): MEM_AP Packed Transfers:
> disabled Debug: 211 174 arm_adi_v5.c:727 mem_ap_init(): MEM_AP CFG: large
> data 0, long address 0, big-endian 0
> Error: 212 3761 adi_v5_jtag.c:450 jtagdp_overrun_check(): Timeout
> during WAIT recovery
> Error: 213 3780 arm_adi_v5.c:845 dap_lookup_cs_component(): Can't read
> component with base address 0x80030000, the corresponding core might
> be turned off
> Debug: 214 3780 openocd.c:150 handle_init_command(): target examination
> failed

It might be that your target definition is not for the first core on the 
device, or that the application cpu cores are not yet booted at the time you 
try to connect to them. If I recall correctly, on the Snapdragon CPUs there is 
an additional modem core that has control over the system at boot time. You 
may need to wait a bit longer after a reset. Apart from that I cannot say 
much, the problem seems not related to aarch64 support in general.

BR,
Matthias