efivar_entry_set_get_size(9)

💅 efivar_entry_set_get_size(9) 💅

okay so bestie, we're in the Kernel API Manual and this page is all about one very special (and lowkey complex) function. no cap, it's giving atomic setter-plus-size-getter energy. 🦋

📛 NAME 📛

efivar_entry_set_get_size — call set_variable() and get new size (atomic). ✨

✨ SYNOPSIS ✨

int efivar_entry_set_get_size (struct efivar_entry *entry , u32
attributes , unsigned long *size , void *data , bool *set );

🎀 ARGUMENTS 🎀

• entry — entry containing variable to set and get. 👑
• attributes — attributes of variable to be written. 🎀
• size — size of data buffer. 🦋
• data — buffer containing data to write. 💖
• set — did the set_variable call succeed? (that's the question, bestie) 🙈

💖 DESCRIPTION 💖

okay so real talk: this is a pretty special (complex) function. See efivarfs_file_write. 🔥

It atomically calls set_variable for entry, and if the call is successful, returns the new size of the variable from get_variable in size. The success of set_variable is indicated by set. periodt. 💅

Returns 0 on success, -EINVAL if the variable data is invalid, -ENOSPC if the firmware does not have enough available space, or a converted EFI status code if either of set_variable or get_variable fail.

and heads up: if the EFI variable does not exist when calling set_variable (EFI_NOT_FOUND). 🌸

🌈 SEE ALSO 🌈

Kernel file ./fs/efivarfs/vars.c is the homegirl here, and the besties are:

• efivar_init(9)
• efivar_entry_delete(9)
• efivar_entry_size(9)
• __efivar_entry_get(9)
• efivar_entry_get(9)

xoxo, your local Unix bestie 💖 source/version: ./fs/efivarfs · date: October 2026 · for efivar_entry_set_get_size(9) 🎀✨