igb_check_alt_mac_addr(9)

💖 igb_check_alt_mac_addr — Kernel API Manual ✨

okay so bestie, welcome to igb_check_alt_mac_addr(9), the little function that makes sure the right MAC address is the main character 🎀. this whole page lives in the Kernel API Manual, and honestly? it's giving "small function, huge responsibility" and we're obsessed.

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✨ NAME ✨

igb_check_alt_mac_addr — check for alternate MAC addr 💅

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🌸 SYNOPSIS 🌸

s32 igb_check_alt_mac_addr (struct e1000_hw *hw );

like yes, it returns an s32, and yes, the space before the closing paren is canon, don't come for me 🫶

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🦋 ARGUMENTS 🦋

• hw — pointer to the HW structure. literally the whole hardware vibe lives in there, and this function is gonna poke at it 👑

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💖 DESCRIPTION 💖

so what does it actually do? okay so — it checks the nvm for an alternate MAC address 🔥

and listen, an alternate MAC address can be set up by pre-boot software, which means it's not just some random address, it's formal. it must be treated like a permanent address, and it must override the actual permanent MAC address. no cap, it outranks the original 😭💀

if an alternate MAC address is found, it gets saved in the hw struct AND programmed into RAR0, and the function returns success ✨. otherwise? the function returns an error 🙈. that's it, that's the whole plot.

ngl this is one of those "tiny function, big consequences" situations — the override thing is not a suggestion, it's a rule 💜

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🌈 SEE ALSO 🌈

• Kernel file ./drivers/net/ethernet/intel/igb/e1000_mac.c
• igb_get_bus_info_pcie(9), igb_clear_vfta(9), igb_write_vfta(9), igb_init_rx_addrs(9), igb_find_vlvf_slot(9), igb_vfta_set(9), igb_rar_set(9), igb_mta_set(9), igb_hash_mc_addr(9), igb_i21x_hw_doublecheck(9), igb_update_mc_addr_list(9), igb_clear_hw_cntrs_base(9), igb_check_for_copper_link(9), igb_setup_link(9), igb_config_collision_dist(9), igb_set_fc_watermarks(9), igb_set_default_fc(9), igb_force_mac_fc(9), igb_config_fc_after_link_up(9), igb_get_speed_and_duplex_copper(9), igb_get_hw_semaphore(9), igb_put_hw_semaphore(9), igb_get_auto_rd_done(9), igb_valid_led_default(9), igb_id_led_init(9), igb_cleanup_led(9), igb_blink_led(9), igb_led_off(9), igb_disable_pcie_master(9), igb_validate_mdi_setting(9), igb_write_8bit_ctrl_reg(9), igb_enable_mng_pass_thru(9)

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and that's the page, bestie 💜 this lil icon dropped from ./drivers/net/ethernet/intel/igb back in October 2026, and it's still serving looks as igb_check_alt_mac_addr(9). periodt 🎀✨