rivafb_setcolreg(9)

💅 rivafb_setcolreg 💅

okay so real talk, this is rivafb_setcolreg from the Kernel API Manual, section 9 — and bestie, the NAME section is literally just the function name and then… nothing. empty. a whole blank. we're working with the vibes alone here 💀 (the description below does the heavy lifting, don't worry).

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✨ SYNOPSIS ✨

int rivafb_setcolreg (unsigned regno , unsigned red , unsigned green ,
       unsigned blue , unsigned transp , struct fb_info *info );

that's the whole signature, character for character, no cap 🫶

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🎀 ARGUMENTS 🎀

• regno — the register index. which slot we're poking at 💅
• red — the red component 🌹
• green — the green component 🍀
• blue — the blue component 🦋
• transp — transparency, yes ma'am ✨
• info — a pointer to the fb_info object holding all the info for the current riva board 👑

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🌸 DESCRIPTION 🌸

so what does it actually do? it sets a single color register. one (1) register. that's it, that's the job 💖

and the values you hand it — red, green, blue, transp — they've got a 16 bit magnitude. sixteen whole bits of magnitude, bestie, that's the vibe check they pass 🔥

CALLED FROM: fbcmap.c:fb_set_cmap — like, that's the caller, that's who's knocking on the door 🚪✨

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⭐ RETURN ⭐

it returns != 0 when regno is invalid. so like, nonzero means "no ❤️", zero means "slay 💅". invalid regno = you get a nonzero back, periodt.

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🌈 SEE ALSO 🌈

first up, the kernel file itself:

• ./drivers/video/fbdev/riva/fbdev.c

and the whole friend group 👯‍♀️:

• rivafb_load_cursor_image(9)
• riva_wclut(9)
• riva_rclut(9)
• riva_save_state(9)
• riva_load_state(9)
• riva_load_video_mode(9)
• rivafb_do_maximize(9)
• riva_get_cmap_len(9)
• rivafb_pan_display(9)
• rivafb_fillrect(9)
• rivafb_copyarea(9)
• rivafb_imageblit(9)
• rivafb_cursor(9)

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💜 quick reminder bestie: 16 bit magnitude on those color values, and nonzero return = invalid regno. that's the whole tea. don't forget it 🍓

anyway, that's the page! sourced from ./drivers/video/fbdev/riva, October 2026 edition, handed down from the Kernel API Manual section 9 — go forth and set those color registers, icon 👑✨🧚💖