sf1_write(9)

✨ sf1_write ✨ (kernel API manual, section 9, bestie)

okay so we're in the kernel API manual today, section 9, and the star of the show is sf1_write — the little function that pushes data at the serial flash. no cap, it's a tiny one, but it's important, so let's get into it 💅

---

🌸 NAME 🌸

sf1_write — write data to the serial flash

that's it. that's the whole name section. she's efficient 💖

---

🎀 SYNOPSIS 🎀

here's the exact signature, do not come for me about the spacing, this is verbatim:

int sf1_write (struct adapter *adapter , unsigned int byte_cnt , int
cont , int lock , u32 val );

---

🦋 ARGUMENTS 🦋

five of them, and every single one matters, so pay attention bestie:

• adapter — the adapter. yes, that's the whole description. she's mysterious. she's the adapter.
• byte_cnt — number of bytes to write
• cont — whether another operation will be chained
• lock — whether to lock SF for PL access only
• val — value to write

---

✨ DESCRIPTION ✨

so the vibe here: sf1_write writes up to 4 bytes of data to the serial flash. four. bytes. max. it's giving tiny-but-mighty 🧚

and here's the part where you need to actually listen, because it's a whole prerequisite situation:

the location of the write needs to be specified prior to calling this, by issuing the appropriate commands to the serial flash.

so like — this function does not figure out where to put your data. it does not ask questions. it does not read the room. you tell the flash where it's going first, and then you call sf1_write. the way that this is not optional is genuinely so real 😭

---

💜 SEE ALSO 💜

the kernel file lives at ./drivers/net/ethernet/chelsio/cxgb4/t4_hw.c, and honestly the SEE ALSO list here is a whole friend group. an entire friend group. buckle up, we're going through all of them because nobody gets left behind 🫶

t4_wait_op_done_val(9), t4_set_reg_field(9), t4_read_indirect(9), t4_write_indirect(9), t4_record_mbox(9), t4_wr_mbox_meat_timeout(9), t4_memory_rw_init(9), t4_memory_update_win(9), t4_memory_rw_residual(9), t4_memory_rw(9), t4_get_regs_len(9), t4_get_regs(9), t4_eeprom_ptov(9), t4_seeprom_wp(9), t4_get_raw_vpd_params(9), t4_get_vpd_params(9), t4_get_pfres(9), sf1_read(9), flash_wait_op(9), t4_read_flash(9), t4_write_flash(9), t4_get_fw_version(9), t4_get_bs_version(9), t4_get_tp_version(9), t4_get_exprom_version(9), t4_get_vpd_version(9), t4_get_scfg_version(9), t4_get_version_info(9), t4_dump_version_info(9), t4_check_fw_version(9), t4_flash_erase_sectors(9), t4_flash_cfg_addr(9), t4_load_fw(9), t4_phy_fw_ver(9), t4_load_phy_fw(9), t4_fwcache(9), fwcaps16_to_caps32(9), fwcaps32_to_caps16(9), t4_link_acaps(9), t4_link_l1cfg_core(9), t4_restart_aneg(9), t4_handle_intr_status(9), t4_slow_intr_handler(9), t4_intr_enable(9), t4_intr_disable(9), t4_config_rss_range(9), t4_config_glbl_rss(9), t4_config_vi_rss(9), t4_read_rss(9), t4_tp_fw_ldst_rw(9), t4_tp_indirect_rw(9), t4_tp_pio_read(9), t4_tp_pio_write(9), t4_tp_tm_pio_read(9), t4_tp_mib_read(9), t4_read_rss_key(9), t4_write_rss_key(9), t4_read_rss_pf_config(9), t4_read_rss_vf_config(9), t4_read_rss_pf_map(9), t4_read_rss_pf_mask(9), t4_tp_get_tcp_stats(9), t4_tp_get_err_stats(9), t4_tp_get_cpl_stats(9), t4_tp_get_rdma_stats(9), t4_get_fcoe_stats(9), t4_get_usm_stats(9), t4_read_mtu_tbl(9), t4_read_cong_tbl(9), t4_tp_wr_bits_indirect(9), init_cong_ctrl(9), t4_load_mtus(9), t4_get_chan_txrate(9), t4_set_trace_filter(9), t4_get_trace_filter(9), t4_pmtx_get_stats(9), t4_pmrx_get_stats(9), compute_mps_bg_map(9), t4_get_mps_bg_map(9), t4_get_tp_e2c_map(9), t4_get_tp_ch_map(9), t4_get_port_type_description(9), t4_get_port_stats_offset(9), t4_get_port_stats(9), t4_get_lb_stats(9), t4_mdio_rd(9), t4_mdio_wr(9), t4_sge_decode_idma_state(9), t4_sge_ctxt_flush(9), t4_read_sge_dbqtimers(9), t4_fw_hello(9)

and we're not done, there's more, keep going 🔥

t4_fw_bye(9), t4_early_init(9), t4_fw_reset(9), t4_fw_halt(9), t4_fw_restart(9), t4_fw_upgrade(9), t4_fl_pkt_align(9), t4_fixup_host_params(9), t4_fw_initialize(9), t4_query_params_rw(9), t4_set_params_timeout(9), t4_set_params(9), t4_cfg_pfvf(9), t4_alloc_vi(9), t4_free_vi(9), t4_set_rxmode(9), t4_free_encap_mac_filt(9), t4_free_raw_mac_filt(9), t4_alloc_encap_mac_filt(9), t4_alloc_raw_mac_filt(9), t4_alloc_mac_filt(9), t4_free_mac_filt(9), t4_change_mac(9), t4_set_addr_hash(9), t4_enable_vi_params(9), t4_enable_vi(9), t4_enable_pi_params(9), t4_identify_port(9), t4_iq_stop(9), t4_iq_free(9), t4_eth_eq_free(9), t4_ctrl_eq_free(9), t4_ofld_eq_free(9), t4_link_down_rc_str(9), fwcap_to_fwspeed(9), lstatus_to_fwcap(9), t4_handle_get_port_info(9), t4_update_port_info(9), t4_get_link_params(9), t4_handle_fw_rpl(9), init_link_config(9), t4_prep_adapter(9), t4_shutdown_adapter(9), t4_bar2_sge_qregs(9), t4_init_devlog_params(9), t4_init_sge_params(9), t4_init_tp_params(9), t4_filter_field_shift(9), t4_init_portinfo(9), t4_read_cimq_cfg(9), t4_read_cim_ibq(9), t4_read_cim_obq(9), t4_cim_read(9), t4_cim_write(9), t4_cim_read_la(9), t4_tp_read_la(9), t4_idma_monitor_init(9), t4_idma_monitor(9), t4_load_cfg(9), t4_set_vf_mac_acl(9), t4_read_pace_tbl(9), t4_get_tx_sched(9), t4_sge_ctxt_rd_bd(9), t4_i2c_rd(9), t4_set_vlan_acl(9), modify_device_id(9), t4_load_boot(9), t4_flash_bootcfg_addr(9)

like I said. whole friend group 💀 slay that we got through all of them

---

okay and for the cute sign-off: this page's footer credits the source as ./drivers/net/ethernet/chelsio... (yes, truncated with an ellipsis, that's literally how it's printed, no I'm not fixing it 🙈), dated October 2026, and it's the page for sf1_write(9). periodt 💖