STRUCT ETM_CONFIG(9)

💖 struct etm_config(9) — the Kernel API Manual, but make it a group chat 💖

okay so bestie, buckle up, because today we're talking about struct etm_config — the literal MAIN CHARACTER of the ETM world. It's a struct that holds all the configuration info related to an ETM, and yes, it's giving "backstage pass to the whole tracing operation." 🌸

This one lives in the Kernel API Manual, section 9, and it's gonna be a whole journey. Grab a strawberry drink 🍓 and let's go.

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✨ SYNOPSIS ✨

Lowkey the biggest vibe reveal of the whole page. Here's the whole struct, verbatim, no cuts, no skips, no "you get the idea":

struct etm_config {
    u32 mode;
    u32 ctrl;
    u32 trigger_event;
    u32 startstop_ctrl;
    u32 enable_event;
    u32 enable_ctrl1;
    u32 enable_ctrl2;
    u32 fifofull_level;
    u8 addr_idx;
    u32 addr_val[ETM_MAX_ADDR_CMP];
    u32 addr_acctype[ETM_MAX_ADDR_CMP];
    u32 addr_type[ETM_MAX_ADDR_CMP];
    u8 cntr_idx;
    u32 cntr_rld_val[ETM_MAX_CNTR];
    u32 cntr_event[ETM_MAX_CNTR];
    u32 cntr_rld_event[ETM_MAX_CNTR];
    u32 cntr_val[ETM_MAX_CNTR];
    u32 seq_12_event;
    u32 seq_21_event;
    u32 seq_23_event;
    u32 seq_31_event;
    u32 seq_32_event;
    u32 seq_13_event;
    u32 seq_curr_state;
    u8 ctxid_idx;
    u32 ctxid_pid[ETM_MAX_CTXID_CMP];
    u32 ctxid_mask;
    u32 sync_freq;
    u32 timestamp_event;
 };

like, that's the whole cast. every single one of them matters. 👑

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🎀 Members 🎀

okay now let's meet the members one by one, because they all have lore.

• mode — controls the various modes supported by this ETM/PTM. it's the vibe-setter fr fr.
• ctrl — used in conjunction with mode. they're a duo, you can't separate them, it's giving iconic partnership.
• trigger_event — setting for register ETMTRIGGER.
• startstop_ctrl — setting for register ETMTSSCR.
• enable_event — setting for register ETMTEEVR.
• enable_ctrl1 — setting for register ETMTECR1.
• enable_ctrl2 — setting for register ETMTECR2.
• fifofull_level — setting for register ETMFFLR.
• addr_idx — index for the address comparator selection.
• addr_val — value for address comparator register.
• addr_acctype — access type for address comparator register.
• addr_type — current status of the comparator register. not the past, not the future, the current status. periodt.
• cntr_idx — index for the counter register selection.
• cntr_rld_val — reload value of a counter register.
• cntr_event — control for counter enable register.
• cntr_rld_event — value for counter reload event register.
• cntr_val — counter value register.
• seq_12_event — event causing the transition from 1 to 2.
• seq_21_event — event causing the transition from 2 to 1.
• seq_23_event — event causing the transition from 2 to 3.
• seq_31_event — event causing the transition from 3 to 1.
• seq_32_event — event causing the transition from 3 to 2.
• seq_13_event — event causing the transition from 1 to 3.
• seq_curr_state — current value of the sequencer register.
• ctxid_idx — index for the context ID registers.
• ctxid_pid — value for the context ID to trigger on.
• ctxid_mask — mask applicable to all the context IDs. all of them. every last one. 💅
• sync_freq — Synchronisation frequency.
• timestamp_event — Defines an event that requests the insertion of a timestamp into the trace stream. time-stamping? we love to see it. ⭐

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🦋 SEE ALSO 🦋

go touch some other docs, bestie, they're right here:

• Kernel file ./drivers/hwtracing/coresight/coresight-etm.h struct etm_drvdata(9)

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ngl the sequencer transitions (1→2, 2→1, 2→3, 3→1, 3→2, 1→3) are lowkey the most dramatic part of this whole page. six events, all iconic, no cap. 🔥

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and that's the whole page, bestie!! 🫶 this little beauty comes to you from ./drivers/hwtracing/coresight, dated October 2026, and it's filed under struct etm_config(9). mwah, go forth and configure your ETM responsibly 💜✨🎀