arm: Support hardware debugging of ARM architecture #15616

W-M-R · 2025-01-20T10:28:26Z

Note: Please adhere to Contributing Guidelines.

Summary

Support hardware debugging of ARM architecture
We can use "up_debugpoint_add" or "up_debugpoint_remove" to add breakpoints, and the hardware will jump into the interrupt after detecting it.

Impact

Currently only available for single core
It will not affect our program.
The debug of arm32 jumps into the exception vector table, and it is also necessary to develop the jump function of the exception vector table in debug mode

Testing

Use arm32 boards, call "up_debugpoint_add", "up_debugpoint_remove" api, and set the breakpoint address.

    if (up_debugpoint_add(DEBUGPOINT_WATCHPOINT_WO, p-1, 1, NULL, NULL))
        {
            printf("Watchpoint added error\n");
        }
    if (up_debugpoint_add(DEBUGPOINT_WATCHPOINT_WO, p+4, 1, NULL, NULL))
        {
            printf("Watchpoint added error\n");
        }
    p[8]++;
    printf("p[8]: %d\n", p[8]);
    p[7]++;
    printf("p[7]: %d\n", p[7]);
    p[4]++;
    printf("p[4]: %d\n", p[4]);
    p[2]++;
    printf("p[2]: %d\n", p[2]);
    p[1]++;
    printf("p[1]: %d\n", p[1]);
    p[0]++;
    printf("p[0]: %d\n", p[0]);

log:

arm_enable_dbgmonitor: found 5 (+1 reserved) breakpoint and 4 watchpoint registers.
arm_enable_dbgmonitor: maximum watchpoint size is 8 bytes.
add_debugpoint: add debugpoints[0]: type = 2 addr = 0x40208f9f
add_debugpoint: add debugpoints[1]: type = 2 addr = 0x40208fa4
p[8]: 1
p[7]: 65
arm_dataabort: Data abort. PC: 0061f6a0 DFAR: 40208fa4 DFSR: 00000002
dump_assert_info: Current Version: NuttX  0.0.0 9d33530389-dirty Jan 21 2025 13:13:34 arm
dump_assert_info: Assertion failed panic: at file: armv7-a/arm_dataabort.c:159 task: hello process: hello 0x61f568
up_dump_register: R0: 00000009 R1: 00000000 R2: 00000049  R3: 40208fa4
up_dump_register: R4: 0061f568 R5: 00000001 R6: 40207fa8  R7: 00000000
up_dump_register: R8: 00000000 SB: 00000000 SL: 00000000  FP: 00000000
up_dump_register: IP: 6000005f SP: 40208f58 LR: 0061f68c  PC: 0061f6a0
up_dump_register: CPSR: 6000005f
dump_tasks:    PID GROUP PRI POLICY   TYPE    NPX STATE   EVENT      SIGMASK          STACKBASE  STACKSIZE      USED   FILLED    COMMAND
dump_tasks:   ----   --- --- -------- ------- --- ------- ---------- ---------------- 0x402003e0      2048       172     8.3%    irq
dump_task:       0     0   0 FIFO     Kthread -   Ready              0000000000000000 0x40204010      4080       712    17.4%    Idle_Task
dump_task:       1     0 192 RR       Kthread -   Waiting Semaphore  0000000000000000 0x40205438      4032       400     9.9%    hpwork 0x40200000 0x40200030
dump_task:       2     2 100 RR       Task    -   Waiting Semaphore  0000000000000000 0x40206850      4056      1072    26.4%    nsh_main
dump_task:       3     3 100 RR       Task    -   Running            0000000000000000 0x40207fb8      4064      1156    28.4%    hello

DFSR: 00000002 indicates that the abnormal debugging mode is entered

Signed-off-by: wangmingrong1 <[email protected]>

nuttxpr · 2025-01-20T10:32:35Z

[Experimental Bot, please feedback here]

This PR template itself meets the NuttX requirements by providing sections for all the requested information. However, a user submitting a PR needs to fill out all the sections completely and accurately for the PR to truly meet the requirements. Simply including the template without filling it out is insufficient.

Specifically, the template addresses the requirements by prompting for:

Summary: Reason for the change, affected code, mechanism of the change, and related issue references.
Impact: Detailed breakdown of the change's effects on various aspects of the system (user experience, build process, hardware, documentation, security, and compatibility).
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The inclusion of the contributing guidelines link further reinforces the importance of adhering to the broader project standards.

acassis

Please include commit message with more information

W-M-R · 2025-01-21T05:22:05Z

Please include commit message with more information

OK, I have improved the description

Signed-off-by: wangmingrong1 <[email protected]>

anchao · 2025-01-21T06:10:57Z

arch/arm/include/arch.h

@@ -164,6 +164,8 @@ typedef struct arch_addrenv_s arch_addrenv_t;
 * Public Function Prototypes
 ****************************************************************************/

+uintptr_t up_read_cpuid(void);


why not reuse this_cpu() / up_cpu_index()?

"up_read_cpuid" means I want to get the features supported by the current cpu instead of which cpu it is? Maybe the name is similar to "up_cpu_index", so should I change it to another name?

I think you don't need to add a new API, because your implementation is not common code, and the relevant interfaces have been implemented. You can refer to the implementation of arm_cpuinfo.c:

cortex-a/r:
cpuid = CP15_GET(MIDR);
cortex-m:
cpuid = getreg32(ARMV6M_SYSCON_CPUID);

anchao · 2025-01-21T06:12:42Z