of_fpga_reg...fy_pre_apply(9)

💅 of_fpga_region_notify_pre_apply — Kernel API Manual ✨

okay bestie, buckle up, because this one is literally the bouncer at the FPGA overlay club 🎀

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✨ NAME ✨

of_fpga_region_notify_pre_apply — the pre-apply overlay notification, aka the "wait, let me check your ID first" of FPGA region land 🫶

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🌸 SYNOPSIS 🌸

int of_fpga_region_notify_pre_apply(struct fpga_region *region,
                                    struct of_overlay_notify_data *nd);

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🦋 ARGUMENTS 🦋

• region — the FPGA region that the overlay was applied to. this is the main character of the whole operation 👑
• nd — the overlay notification data. the little info packet riding along with the notification 💌

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💖 DESCRIPTION 💖

so the way this works is: this function gets called when an overlay that's targeted to an FPGA Region is about to be applied. like, it hasn't happened yet, we're in the pre-game era ⭐

it parses the overlay for properties that influence how the FPGA will be programmed, and it does some checking. yes, there is a vibe check 🔥

if the checks pass → it programs the FPGA. slay, green light, go 💅

if the checks fail → the overlay is rejected and does not get added to the live tree. no cap, it's just not happening, the door is closed 😭

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🎀 RETURN 🎀

• 0 for success 💜
• a negative error code for failure 💀

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🌈 SEE ALSO 🌈

Kernel file ./drivers/fpga/of-fpga-region.c, plus the whole friend group:

• of_fpga_region_find(9)
• of_fpga_region_get_mgr(9)
• of_fpga_region_get_bridges(9)
• child_regions_with_firmware(9)
• of_fpga_region_parse_ov(9)
• of_fpga_region_notify_post_remove(9)
• of_fpga_region_notify(9)
• of_fpga_region_init(9)

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and that's the tea 🍓 this page lives in ./drivers/fpga, dated October 2026, and you can find it filed under of_fpga_reg...fy_pre_apply(9) — mwah, ily, go read the kernel source 🧚💜