STRUCT SPI_NOR_FLASH_PARAMETER(9)

💅 struct spi_nor_flash_parameter(9) — Kernel API Manual ✨

okay bestie, welcome to the kernel API manual, this one's literally about SPI NOR flash parameters and settings, no cap 🫶

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🎀 NAME 🎀

struct spi_nor_flash_parameter — SPI NOR flash parameters and settings.

It's giving "everything you need to know about this flash chip in one struct." This thing includes all the legacy flash parameters and settings — the ones that can be overwritten by the spi_nor_fixups hooks, or overwritten dynamically when the kernel is parsing the JESD216 Serial Flash Discoverable Parameters (SFDP) tables. Two glow-up paths, pick your fighter 💖

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✨ SYNOPSIS ✨

struct spi_nor_flash_parameter {
    u64 bank_size;
    u64 size;
    u32 writesize;
    u32 page_size;
    u8 addr_nbytes;
    u8 addr_mode_nbytes;
    u8 rdsr_dummy;
    u8 rdsr_addr_nbytes;
    u8 n_banks;
    u8 n_dice;
    u8 die_erase_opcode;
    u32 *vreg_offset;
    struct spi_nor_hwcaps           hwcaps;
    struct spi_nor_read_command     reads[SNOR_CMD_READ_MAX];
    struct spi_nor_pp_command       page_programs[SNOR_CMD_PP_MAX];
    struct spi_nor_erase_map        erase_map;
    struct spi_nor_otp              otp;
    int (*set_octal_dtr)(struct spi_nor *nor, bool enable);
    int (*quad_enable)(struct spi_nor *nor);
    int (*set_4byte_addr_mode)(struct spi_nor *nor, bool enable);
    int (*ready)(struct spi_nor *nor);
    const struct spi_nor_locking_ops *locking_ops;
    void *priv;
 };

like, look at her. absolutely iconic field lineup 👑

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🌸 Members 🌸

tour time, bestie — every single field, and what it's actually doing:

• bank_size — the flash memory bank density, in bytes. your bank's size, literally 💸
• size — the total flash memory density in bytes. the whole thing, the full meal.
• writesize — the minimal writable flash unit size. it defaults to 1. for ECC-ed flashes, set this to the ECC unit size, periodt.
• page_size — the page size of the SPI NOR flash memory 📄
• addr_nbytes — number of address bytes to send.
• addr_mode_nbytes — number of address bytes of the current address mode. highkey useful when the flash operates with 4B opcodes but still needs the internal address mode for opcodes that don't have a 4B opcode correspondent. iykyk 🧚
• rdsr_dummy — dummy cycles needed for the Read Status Register command in octal DTR mode.
• rdsr_addr_nbytes — dummy address bytes needed for the Read Status Register command in octal DTR mode.
• n_banks — number of banks.
• n_dice — number of dice in the flash memory. yes, dice 🎲 (that's the plural of die here, not the thing you roll, don't come for me)
• die_erase_opcode — die erase opcode. defaults to SPINOR_OP_CHIP_ERASE.
• vreg_offset — volatile register offset for each die.
• hwcaps — describes the read and page program hardware capabilities.
• reads — read capabilities, ordered by priority: the higher the index in the array, the higher the priority. queue up, besties 💅
• page_programs — page program capabilities, ordered by priority: the higher the index in the array, the higher the priority. same energy, different array.
• erase_map — the erase map parsed from the SFDP Sector Map Parameter Table.
• otp — SPI NOR OTP info.
• set_octal_dtr — enables or disables SPI NOR octal DTR mode.
• quad_enable — enables SPI NOR quad mode.
• set_4byte_addr_mode — puts the SPI NOR in 4 byte addressing mode.
• ready — (optional) some flashes might use a different mechanism than reading the status register to indicate they are ready for a new command. not all heroes read the status register 🙈
• locking_ops — SPI NOR locking methods.
• priv — the flash's private data. mind your business, it's private 💀

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🦋 SEE ALSO 🦋

go read these next, bestie, they're all in the same friend group:

• Kernel file ./drivers/mtd/spi-nor/core.h
• struct spi_nor_erase_type(9)
• struct spi_nor_erase_command(9)
• struct spi_nor_erase_region(9)
• struct spi_nor_erase_map(9)
• struct spi_nor_locking_ops(9)
• struct spi_nor_otp_organization(9)
• struct spi_nor_otp_ops(9)
• struct spi_nor_otp(9)
• struct spi_nor_fixups(9)
• struct spi_nor_id(9)
• struct flash_info(9)
• struct spi_nor_manufacturer(9)
• struct sfdp(9)
• spi_nor_needs_sfdp(9)

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🌈 sign-off 🌈

this lil masterpiece lives in ./drivers/mtd/spi-nor, dated October 2026, and it's the struct spi_n...sh_parameter(9) page — go forth and flash responsibly, ily, bye 🫶💖✨