pci_read_rom(9)

💖 pci_read_rom(9) 💖

okay so this is a page from the Kernel API Manual and bestie, it's literally called pci_read_rom and it does exactly what it says on the tin: it reads a PCI ROM. no cap. let's get into it 🫶

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✨ NAME ✨

pci_read_rom — read a PCI ROM 🌸

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✨ SYNOPSIS ✨

ssize_t pci_read_rom (struct file *filp , struct kobject *kobj , const
       struct bin_attribute *bin_attr , char *buf , loff_t off , size_t count
       );

like, yes, that's a whole lot of parameters. she's got range. 💅

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✨ ARGUMENTS ✨

• filp — the sysfs file, the actual file object we're working with 🎀
• kobj — the kernel object handle, aka who we're talking about
• bin_attr — the struct bin_attribute for this file, her whole personality
• buf — where we put the data we read from the ROM. the drop-off spot 📦
• off — file offset, ie. where in the file we start
• count — how many bytes we're reading

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✨ DESCRIPTION ✨

so the whole vibe: put count bytes starting at off into buf, and those bytes come from the ROM in the PCI device that corresponds to kobj. that's it. that's the function. iconic, honestly 👑

lowkey a perfect little copy-paste job: offset in, count in, bytes out into your buffer. no drama, no surprises ✨

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✨ SEE ALSO ✨

fr fr go look at the kernel file ./drivers/pci/pci-sysfs.c and also these besties:

• pci_read_legacy_io(9)
• pci_write_legacy_io(9)
• pci_mmap_legacy_mem(9)
• pci_mmap_legacy_io(9)
• pci_mmap_resource(9)
• pci_write_rom(9)

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and that's the whole page, bestie, you ate that 🍓 this lil gem comes to you from ./drivers/pci, dated October 2026 — mwah, stan the kernel docs, periodt 💜🦋