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It took me some time to rework the device tree bindings but it looks like it starts to work! View the code on [Gist](https://gist.github.com/austriancoder/6196fa33011a120a01dd54dbd077a60d).Gets loaded into : [ 3.358155] vivante: module is from the staging directory, the quality is unknown, you have been warned. [ 3.373087] imx-sgtl5000 sound.15: sgtl5000 2028000.ssi mapping ok [ 3.379150] [drm] add child gpu2d [ 3.379154] [drm] add child gpu3d [ 3.380395] vivante-gpu 134000.gpu2d: pre gpu[idx]: 0x00000000 [ 3.380401] vivante-gpu 134000.gpu2d: adding core @idx 1 [ 3.380408] vivante-gpu 134000.gpu2d: post gpu[idx]: 0xecb56c10 [ 3.380460] vivante gpu-subsystem.11: bound 134000.gpu2d (ops gpu_ops [vivante]) [ 3.380467] vivante-gpu 130000.gpu3d: pre gpu[idx]: 0x00000000 [ 3.380473] vivante-gpu 130000.gpu3d: adding core @idx 0 [ 3.380479] vivante-gpu 130000.gpu3d: post gpu[idx]: 0xecb57210 [ 3.380502] vivante gpu-subsystem.11: bound 130000.gpu3d (ops gpu_ops [vivante]) [ 3.380533] IO:R f0200018 14010000 [ 3.380537] IO:R f0200020 00002000 [ 3.380540] IO:R f0200024 00005108 [ 3.380546] vivante gpu-subsystem.11: model: 2000 [ 3.380551] vivante gpu-subsystem.11: revision: 5108 [ 3.380554] IO:R f020001c e0296cad [ 3.380558] IO:R f0200034 c9799eff [ 3.380561] IO:R f0200074 2efbf2d9 [ 3.380564] IO:R f0200084 00000000 [ 3.380567] IO:R f0200088 00000000 [ 3.380572] vivante gpu-subsystem.11: minor_features: c9799eff [ 3.380578] vivante gpu-subsystem.11: minor_features1: 2efbf2d9 [ 3.380583] vivante gpu-subsystem.11: minor_features2: 0 [ 3.380588] vivante gpu-subsystem.11: minor_features3: 0 [ 3.380592] IO:R f0200000 00070100 [ 3.408629] IO:R f0200004 7fffffff [ 3.408632] IO:R f0200000 00070100 [ 3.412940] vivante gpu-subsystem.11: 130000.gpu3d: using IOMMU [ 3.413080] IO:R f01f8018 14010000 [ 3.413083] IO:R f01f8020 00000320 [ 3.413087] IO:R f01f8024 00005007 [ 3.413093] vivante gpu-subsystem.11: model: 320 [ 3.413098] vivante gpu-subsystem.11: revision: 5007 [ 3.413101] IO:R f01f801c e02c7eca [ 3.413105] IO:R f01f8034 c1399eff [ 3.413108] IO:R f01f8074 020fb2db [ 3.413111] IO:R f01f8084 00000000 [ 3.413114] IO:R f01f8088 00000000 [ 3.413120] vivante gpu-subsystem.11: minor_features: c1399eff [ 3.413126] vivante gpu-subsystem.11: minor_features1: 20fb2db [ 3.413131] vivante gpu-subsystem.11: minor_features2: 0 [ 3.413136] vivante gpu-subsystem.11: minor_features3: 0 [ 3.413139] IO:R f01f8000 00070100 [ 3.438615] IO:R f01f8004 7fffffff [ 3.438619] IO:R f01f8000 00070100 [ 3.442583] vivante gpu-subsystem.11: 134000.gpu2d: using IOMMU [ 3.442681] [drm] Initialized vivante 1.0.0 20130625 on minor 1

Sometimes is is quite handy to have access to a JTAG interface to look more deeply into problems. The weapon of choice is an Olimex ARM-USB-OCD-H JTAG in combination with OpenOCD 0.8.0. First we will need to install OpenOCD. apt-get install libftdi-dev Download and extract OpenOCD 0.8.0 run ./configure run make && make install This should give you an OpenOCD installation with the following configuration: OpenOCD configuration summary ————————————————– MPSSE mode of FTDI based devices yes (auto) ST-Link JTAG Programmer yes (auto) TI ICDI JTAG Programmer yes (auto) Keil ULINK JTAG Programmer yes (auto) Altera USB-Blaster II Compatible yes (auto) Segger J-Link JTAG Programmer yes (auto) OSBDM (JTAG only) Programmer yes (auto) eStick/opendous JTAG Programmer yes (auto) Andes JTAG Programmer yes (auto) Versaloon-Link JTAG Programmer yes (auto) USBProg JTAG Programmer yes (auto) Raisonance RLink JTAG Programmer yes (auto) Olimex ARM-JTAG-EW Programmer yes (auto) CMSIS-DAP Compliant Debugger no ...

I did spend quite some time the last days to figure out how the MMU v1 could work and what all the code in the v4 Kernel sources does. It took quite some time and a little hint from Russel to finally understand it. So lets start with the technical details. The MMU uses a page table with a maximum size of 256KB. Where each Page Table Entry (PTE) is 4 byte long. The used page size is 4K and can not be changed via some registers etc. Lets have a look at the bit layout of a PTE. ...

Today I wanted to debug a Qt based application within QtCreator but failed. After a quick google I found the solution: View the code on [Gist](https://gist.github.com/austriancoder/c2733a5ca5cfa9c23fe99c27811813d3).

I did spend some time to find the cause for the rendering issues during running some egls2 demos. The fix is a simple one-liner and I would say that GC8xx and GC2000 are ‘equal’ now. That means general work on etnaviv can start now. Currently I am looking in different problem zones and where to start. Update mesa fork Start working on an improved compiler Start working on an kernel interface I think that Rob will start soon on the kernel interface and the mesa update should be doable during some hours. So I think the next big and important step is to improve the compiler. What should I say… I have basic compiler understanding, did wrote a compiler and VM during my study… thats it. I have never written a single line of glsl and I do not completely understand the Vivante GPU. So a perfect starting point for doing some hacking 🙂 The success rate will be quite low and I hope to not lose my motivation too soon.