[PATCH] arm64: zynqmp: Support semhosting boot method
Sean Anderson
sean.anderson at seco.com
Fri Feb 16 17:09:27 CET 2024
On 2/16/24 11:03, Sean Anderson wrote:
> On 2/16/24 10:06, Michal Simek wrote:
>>
>>
>> On 2/16/24 14:48, Michal Simek wrote:
>>>
>>>
>>> On 2/15/24 20:31, Sean Anderson wrote:
>>>> On 2/15/24 14:08, Michal Simek wrote:
>>>>>
>>>>>
>>>>> On 2/15/24 18:19, Sean Anderson wrote:
>>>>>> Currently, when we boot from JTAG we try to boot U-Boot from RAM.
>>>>>> However, this is a bit tricky to time, since the debugger has to wait
>>>>>> for SPL to initialize RAM before it can load U-Boot. This can result in
>>>>>> long waits, since occasionally initializing RAM (and other things in
>>>>>> psu_init) takes a long time to complete and the debugger must wait for
>>>>>> this worst case.
>>>>>>
>>>>>> Support semihosting if it is enabled, as it lets U-Boot tell the
>>>>>> debugger when we are ready for the image. This means we don't have to
>>>>>> wait any more than necessary. We don't change the default config to
>>>>>> ensure we don't break compatibility with existing debuggers that don't
>>>>>> expect us to hit semihosting breakpoints.
>>>>>>
>>>>>> Signed-off-by: Sean Anderson <sean.anderson at seco.com>
>>>>>> ---
>>>>>>
>>>>>> arch/arm/mach-zynqmp/spl.c | 10 ++++++++--
>>>>>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/arch/arm/mach-zynqmp/spl.c b/arch/arm/mach-zynqmp/spl.c
>>>>>> index a0f35f36faa..5af735aa5ce 100644
>>>>>> --- a/arch/arm/mach-zynqmp/spl.c
>>>>>> +++ b/arch/arm/mach-zynqmp/spl.c
>>>>>> @@ -9,6 +9,7 @@
>>>>>> #include <image.h>
>>>>>> #include <init.h>
>>>>>> #include <log.h>
>>>>>> +#include <semihosting.h>
>>>>>> #include <spl.h>
>>>>>> #include <linux/delay.h>
>>>>>>
>>>>>> @@ -66,6 +67,11 @@ void spl_board_init(void)
>>>>>> }
>>>>>> #endif
>>>>>>
>>>>>> +static u32 jtag_boot_device(void)
>>>>>> +{
>>>>>> + return semihosting_enabled() ? BOOT_DEVICE_SMH : BOOT_DEVICE_RAM;
>>>>>> +}
>>>>>> +
>>>>>> void board_boot_order(u32 *spl_boot_list)
>>>>>> {
>>>>>> spl_boot_list[0] = spl_boot_device();
>>>>>> @@ -75,7 +81,7 @@ void board_boot_order(u32 *spl_boot_list)
>>>>>> if (spl_boot_list[0] == BOOT_DEVICE_MMC2)
>>>>>> spl_boot_list[1] = BOOT_DEVICE_MMC1;
>>>>>>
>>>>>> - spl_boot_list[2] = BOOT_DEVICE_RAM;
>>>>>> + spl_boot_list[2] = jtag_boot_device();
>>>>>> }
>>>>>>
>>>>>> u32 spl_boot_device(void)
>>>>>> @@ -97,7 +103,7 @@ u32 spl_boot_device(void)
>>>>>>
>>>>>> switch (bootmode) {
>>>>>> case JTAG_MODE:
>>>>>> - return BOOT_DEVICE_RAM;
>>>>>> + return jtag_boot_device();
>>>>>> #ifdef CONFIG_SPL_MMC
>>>>>> case SD_MODE1:
>>>>>> case SD1_LSHFT_MODE: /* not working on silicon v1 */
>>>>>
>>>>> Good timing. Can you please tell me how to test this? What's the setup?
>>>>> Which debugger are you using?
>>>>
>>>> I am using OpenOCD with the patches at https://cas5-0-urlprotect.trendmicro.com:443/wis/clicktime/v1/query?url=https%3a%2f%2freview.openocd.org%2fc%2fopenocd%2f%2b%2f8133&umid=6e1be473-0b3f-4bc4-a4f0-403592e74baf&auth=d807158c60b7d2502abde8a2fc01f40662980862-afc15b07b0f91c910f832185958363d84f990a08
>>>>
>>>
>>> I am trying it on the top of the latest git but getting issue with event block and no idea how to fix it.
>>>
>>> # sudo openocd -f /usr/local/share/openocd/scripts/interface/ftdi/digilent_jtag_hs3.cfg -f /usr/local/share/openocd/scripts/target/xilinx_zynqmp.cfg
>>> Open On-Chip Debugger 0.12.0+dev-01509-g6d288937cb2d (2024-02-16-12:22)
>>> Licensed under GNU GPL v2
>>> For bug reports, read
>>> https://cas5-0-urlprotect.trendmicro.com:443/wis/clicktime/v1/query?url=http%3a%2f%2fopenocd.org%2fdoc%2fdoxygen%2fbugs.html&umid=6e1be473-0b3f-4bc4-a4f0-403592e74baf&auth=d807158c60b7d2502abde8a2fc01f40662980862-f501ab9aa5516ff666e387e53598fd624398f1bc
>>> Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'.
>>> wrong # args: should be "-event <event-name> <event-body>"
>>>
>>>
>>> Do you know how to fix it?
>>
>>
>> I actually bisect it and found that it is caused by
>> jtag: rewrite jim_jtag_configure() as COMMAND_HANDLER
>> ea2e26f7d521f5755b4bfda7bf12d99650277421
>
> Interesting. I have been testing with 0.12.
>
>> # sudo openocd -f /usr/local/share/openocd/scripts/interface/ftdi/digilent_jtag_smt2_nc.cfg -f /usr/local/share/openocd/scripts/target/xilinx_zynqmp.cfg
>
> FWIW after installing the udev rules I do not need sudo
>
>> Open On-Chip Debugger 0.12.0+dev-01512-g214206ebb972 (2024-02-16-15:38)
>> Licensed under GNU GPL v2
>> For bug reports, read
>> https://cas5-0-urlprotect.trendmicro.com:443/wis/clicktime/v1/query?url=http%3a%2f%2fopenocd.org%2fdoc%2fdoxygen%2fbugs.html&umid=6e1be473-0b3f-4bc4-a4f0-403592e74baf&auth=d807158c60b7d2502abde8a2fc01f40662980862-f501ab9aa5516ff666e387e53598fd624398f1bc
>> none separate
>> Info : auto-selecting first available session transport "jtag". To override use 'transport select <transport>'.
>> Info : Hardware thread awareness created
>> boot_apu
>> Info : Listening on port 6666 for tcl connections
>> Info : Listening on port 4444 for telnet connections
>> Warn : An adapter speed is not selected in the init scripts. OpenOCD will try to run the adapter at very low speed (100 kHz).
>> Warn : To remove this warnings and achieve reasonable communication speed with the target, set "adapter speed" or "jtag_rclk" in the init scripts.
>> Info : clock speed 100 kHz
>> Info : TAP uscale.tap does not have valid IDCODE (idcode=0x48e70126)
>> Info : JTAG tap: uscale.ps tap/device found: 0x24738093 (mfg: 0x049 (Xilinx), part: 0x4738, ver: 0x2)
>> Info : JTAG tap: uscale.tap tap/device found: 0x5ba00477 (mfg: 0x23b (ARM Ltd), part: 0xba00, ver: 0x5)
>> Info : JTAG tap: uscale.ps tap/device found: 0x24738093 (mfg: 0x049 (Xilinx), part: 0x4738, ver: 0x2)
>> Error: JTAG-DP STICKY ERROR
>> Error: [uscale.a53.0] Examination failed
>> Warn : target uscale.a53.0 examination failed
>> Info : [uscale.axi] Examination succeed
>> Info : starting gdb server for uscale.a53.0 on 3333
>> Info : Listening on port 3333 for gdb connections
>> Info : gdb port disabled
>>
>> but with zcu102 I am still not able to connect because error above.
>> The same behavior with recording SOM IDs I see on kv260 (via hs3 cable).
>> It looks like that not everything is working for zynqmp.
>
> Is this with the boot mode set to JTAG? If so, you will not be able to
> examine any of the CPUs until you have released them from reset. So you
> should be able to run
>
> targets uscale.axi
> boot_pmu /path/to/pmu-firmware.bin
> boot_apu /path/to/u-boot-spl.bin
>
> to boot a CPU. If you want to silence the above error, you can add
>
> uscale.a53.0 configure -defer-examine
>
> to your config. So the full command would be
>
> $ openocd -f interface/ftdi/digilent_jtag_smt2_nc.cfg \
> -f target/xilinx_zynqmp.cfg \
> -c 'uscale.a53.o configure -defer-examine' \
> -c init -c 'targets uscale.axi' \
> -c 'boot_pmu /path/to/pmu-firmware.bin' \
> -c 'boot_apu /path/to/boot.bin'
>
> Let me know if that works for you.
Oh, and I forgot to mention, but if you are testing semihosting then you will need to add
-c 'uscale.a53.0 arm semihosting enable'
to the end of that. I also find setting the semihosting base directory with
-c 'uscale.a53.0 arm semihosting_basedir $IMAGEDIR'
to be helpful.
As you can imagine this is a long command line, so I have a config which looks like
source [find interface/ftdi/digilent_jtag_smt2_nc.cfg]
adapter speed 25000
source [find target/xilinx_zynqmp.cfg]
uscale.a53.0 configure -defer-examine
proc boot {imagedir machine} {
targets uscale.axi
boot_pmu "${imagedir}/pmu-firmware-${machine}.bin"
boot_apu "${imagedir}/u-boot-spl.bin"
uscale.a53.0 arm semihosting enable
uscale.a53.0 arm semihosting_basedir $imagedir
}
which I invoke like
$ openocd -f my_config.cfg -c init -c 'boot /path/to/images my-machine'
--Sean
[Embedded World 2024, SECO SpA]<https://www.messe-ticket.de/Nuernberg/embeddedworld2024/Register/ew24517689>
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