AppleIntelFramebufferAzul.kext

A couple of days ago I blogged about the discovery of fBacklightFrequency and fBacklightMax. Today I like to add four more. This time; fStolenMemorySize, fFramebufferMemorySize, fCursorBytes and the amount of VRAM:

00 00 16 0A 00 03 03 03 00 00 00 04 00 00 00 01
00 00 F0 00 00 00 00 40 D9 0A 00 00 D9 0A 00 00
00 00 00 00 00 00 00 00 00 00 10 00 02 00 00 00
30 00 00 00 01 05 12 00 04 00 00 00 04 00 00 00
02 04 12 00 00 08 00 00 82 00 00 00 FF 00 01 00
01 00 00 00 40 00 00 00 04 00 00 00 00 00 07 00
04 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00

Note: The last 24 bytes are the same for all data sets.

fStolenMemorySize: 00 00 00 04 = 0x4000000 = 64 MB
fFramebufferMemorySize: 00 00 00 01 = 0x1000000 = 16 MB
fCursorBytes: 00 00 F0 00 = 0xF00000 = 15728640 / 10 = 1572864
VRAM: 00 00 00 40 = 1024 MB
connector-type: There are five different connector types, being:

02 00 00 00 – LVDS
04 00 00 00 – DVI
00 04 00 00 – DP
00 08 00 00 – HDMI
00 0C 00 00 – Thunderbolt?

Note: Lowering fStolenMemorySize triggered the following error:

Assertion failed: minStolenSize <= fStolenMemorySize

Here is a handy table to convert values without the calculator:

00 00 00 01 = 0x01000000 = 16 MB
00 00 00 02 = 0x02000000 = 32 MB
00 00 00 04 = 0x04000000 = 64 MB
00 00 00 06 = 0x06000000 = 96 MB
00 00 00 08 = 0x08000000 = 128 MB
00 00 00 10 = 0x10000000 = 256 MB
00 00 00 18 = 0x18000000 = 384 MB
00 00 00 20 = 0x20000000 = 512 MB
00 00 00 30 = 0x30000000 = 768 MB
00 00 00 40 = 0x40000000 = 1024 MB
00 00 00 60 = 0x60000000 = 1536 MB
00 00 00 80 = 0x80000000 = 2048 MB

This information should come in handy for people who want to experiment with frame buffer data 😉

Update: connector-type data values added.

5 thoughts on “AppleIntelFramebufferAzul.kext

  1. So do these values (fStolenMemorySize, fFramebufferMemorySize) have any effect on what the BIOS settings. i.e…..shared memory can be set to? When I set the BIOS to another value except 64mb I get some strange MCA panic error that I have never seen before.

  2. Pingback: Yosemite DP6 with HD4600 | Pike's Universum

  3. For anyone reading this post, FYI, Pike has more updated information in later posts, including in his new script for modifying AppleIntelFramebufferAzul. But one thing to note here is that the one connector type above is incorrect. The post shows “04 00 00 00” for DVI but that string is actually for “eDP” (the internal version of display port). If you want DVI, the hex you want is “00 02 00 00”.

  4. Pingback: AppleIntelSKLGraphicsFramebuffer.kext – Pike's Universum

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