HI,
Add some new findings:
"Debug: 1090 283 xtensa.c:2068 xtensa_poll(): [plmp.smcu] PWRSTAT: read 
0x10011111, clear 0x10010000, reread 0x80001111"
"Debug: 1199 346 xtensa.c:2068 xtensa_poll(): [plmp.pmcu] PWRSTAT: read 
0x90011111, clear 0x10010000, reread 0x80001111"


It seems that all APB writes will be problematic, as in the PWRSTAT register 
above, the default read =0x10011111 is correct.But when written, bit31 becomes 
1 again.


---

**[tickets:#445] openocd with xtensa core problem(about debug data reg)**

**Status:** new
**Milestone:** 0.11.0
**Created:** Fri Dec 06, 2024 05:30 AM UTC by vitocichen
**Last Updated:** Sat Dec 07, 2024 11:58 AM UTC
**Owner:** nobody


HI,
I am debugging xtensa core using openocd tool. The connection relationship of 
my system is as follows:
<< jlink--->coresight dap--->APB_AP(ap_num=0)----->xtensa core0/1/2 >>

The gdb tool I use is xt-gdb, but I find that the values of my pc registers, 
a0-a15,ar0-ar15, etc. are strange during reuse, their highest bit bit31 is 
always 1, bit30 is always 0, but this value is wrong.

I finally found that openocd had a problem when reading and writing the DDR 
(debug data reg) register, in order to better explain the phenomenon.
I've added a test function in openocd source, in the SRC/target/xtensa/xtensa. 
C I added a test function, the code is as follows:

/************************************************************************************/
void ddr_test(struct target target)
{
struct xtensa xtensa = target_to_xtensa(target);
uint8_t a3_buf[4]={0};
LOG_DEBUG("***ddr test******");
xtensa_queue_dbg_reg_write(xtensa, XDMREG_DDR, 0x12345678);
xtensa_queue_dbg_reg_read(xtensa, XDMREG_DDR,a3_buf);
LOG_DEBUG("A3[0]=%X",a3_buf[0]);
LOG_DEBUG("A3[1]=%X",a3_buf[1]);
LOG_DEBUG("A3[2]=%X",a3_buf[2]);
LOG_DEBUG("A3[3]=%X",a3_buf[3]);
xtensa_queue_dbg_reg_write(xtensa, XDMREG_DDR, 0);
xtensa_queue_dbg_reg_read(xtensa, XDMREG_DDR,a3_buf);
LOG_DEBUG("A3[0]=%X",a3_buf[0]);
LOG_DEBUG("A3[1]=%X",a3_buf[1]);
LOG_DEBUG("A3[2]=%X",a3_buf[2]);
LOG_DEBUG("A3[3]=%X",a3_buf[3]);
xtensa_queue_dbg_reg_write(xtensa, XDMREG_DDR, 0x5a5a8080);

xtensa_queue_dbg_reg_read(xtensa, XDMREG_DDR,a3_buf);
LOG_DEBUG("A3[0]=%X",a3_buf[0]);
LOG_DEBUG("A3[1]=%X",a3_buf[1]);
LOG_DEBUG("A3[2]=%X",a3_buf[2]);
LOG_DEBUG("A3[3]=%X",a3_buf[3]);
}
/************************************************************************************/
I put the above test function in a lot of event locations like 
xtensa_halt/xtensa_resume/xtensa_prepare_resume and other places.

Then I found that the DDR test always fails, bit31 is always 1, bit30 is always 
0, such as the above result:
0x12345678----->0x82345678 0x0---->0x8000000 0x5a5a8080--->9a5a8080

I tried to modify the speed of jlink can not improve this, below is my cfg 
file, can you help me find out the reason?

Here is my cfg file:

/************************************xxxx.cfg************************************************/
adapter driver jlink
adapter serial 601012352
transport select jtag
gdb_port 20005
bindto 0.0.0.0

source [find mem_helper.tcl]
set _CHIPNAME plmp
set _CPU0NAME smcu
set _CPU1NAME pmcu
set _TARGETNAME_0 $_CHIPNAME.$_CPU0NAME
set _TARGETNAME_1 $_CHIPNAME.$_CPU1NAME

set _CPUTAPID 0x6ba00477

source [find target/swj-dp.tcl]
swj_newdap $_CHIPNAME tap -irlen 4 -expected-id $_CPUTAPID

dap create $_CHIPNAME.dap -chain-position $_CHIPNAME.tap

target create $_CHIPNAME.axi mem_ap -dap $_CHIPNAME.dap -ap-num 1
target create $_TARGETNAME_0 xtensa -dap $_CHIPNAME.dap -ap-num 0 -coreid 1 
-dbgbase 0x0108000
source [find target/xtensa-core-lx7.cfg]

target create $_TARGETNAME_1 xtensa -dap $_CHIPNAME.dap -ap-num 0 -coreid 2 
-dbgbase 0x010c000
source [find target/xtensa-core-lx7.cfg]


---

Sent from sourceforge.net because openocd-devel@lists.sourceforge.net is 
subscribed to https://sourceforge.net/p/openocd/tickets/

To unsubscribe from further messages, a project admin can change settings at 
https://sourceforge.net/p/openocd/admin/tickets/options.  Or, if this is a 
mailing list, you can unsubscribe from the mailing list.


Reply via email to