Flashing Raspberry Pis and android support

[LollosoSi]

Hello! Happy to see this project exists
This thread mentions GUD could be used for Pixel phones, since these have software/hardware disabled video output (a shame). So here I am, with my couple pis giving it a try.

At the moment, I have flashed the debug image with the raspberry pi imager, but it doesn't seem to boot at all.
Pi 3 is a blank screen, Pi 4 shows the logo, logs undervoltage if plugged to pc usb, and that seems to be it.

Looking into the flashed sdcard, /boot is empty, perhaps I missed something. (USB IP can't be configured, neither wpa supplicant file)

Regarding the Pixel kernel side support, do you think it is a feasible implementation?
I know some basics, but I haven't really ever built a functioning kernel, could use some guidance
Thought of this kernel as a starting point

From what I could understand, once the image is running on the raspberry pi and kernel driver is enabled everything should work either by plugging the usb or using usbip, correct me if I am wrong

Thank you in advance

[notro]

At the moment, I have flashed the debug image with the raspberry pi imager, but it doesn't seem to boot at all. Pi 3 is a blank screen, Pi 4 shows the logo, logs undervoltage if plugged to pc usb, and that seems to be it.

The image only supports Pi Zero and Pi4, not Pi3.

If your Pi4 is bought after Q1 2022 look at #17 for a workaround.

Looking into the flashed sdcard, /boot is empty, perhaps I missed something. (USB IP can't be configured, neither wpa supplicant file)

/boot is mounted to the fat boot partiton after boot.

Regarding the Pixel kernel side support, do you think it is a feasible implementation? I know some basics, but I haven't really ever built a functioning kernel, could use some guidance Thought of this kernel as a starting point

That kernel is v5.10 so it should work with the patches in this repo.

I have never worked with Android before so if I were to do this I would first build a kernel and get it onto the device. When that's working I would try the USB mass storage gadget to make sure the gadget side is working. Then I would add the gud patches and make that work.

From what I could understand, once the image is running on the raspberry pi and kernel driver is enabled everything should work either by plugging the usb or using usbip, correct me if I am wrong

Yep, it should.

[LollosoSi]

Using the imager and selecting Raspberry Pi 4 as device seemed to fix the problem.

Could you provide more information about installing the patch into the android kernel?
using patch -p1 < .... doesn't seem to do the trick

[notro]

Please post the output of the command so I can see what goes wrong.

[LollosoSi]

Just noticed I was applying the wrong files. I could apply all the files under linux_patches (host, not gadget)
Will report asap

[LollosoSi]

edit: read the next comment

I was able to apply the patches, compile the kernel and flash it. Phone boots and sees the raspberry pi as 1d50:614d

What now?

To have the kernel image, I just ran from the kernel root:
patch -p1 < buildroot/external/linux-patches/gud/0001-drm-uapi-Add-USB-connector-type.patch
patch -p1 < buildroot/external/linux-patches/gud/0002-drm-Add-GUD-USB-Display-driver.patch
patch -p1 < buildroot/external/linux-patches/gud/0003-drm-gud-Add-GUD_PIXEL_FORMAT_R8.patch
patch -p1 < buildroot/external/linux-patches/gud/0004-drm-gud-Add-GUD_PIXEL_FORMAT_RGB332.patch
patch -p1 < buildroot/external/linux-patches/gud/0005-drm-gud-Add-GUD_PIXEL_FORMAT_RGB888.patch

Then compiled

[LollosoSi]

Correction: I needed to enable gud in the config file
CONFIG_DRM_GUD=y

Compilation now:

  GEN     kernel/kheaders_data.tar.xz
../drivers/gpu/drm/gud/gud_pipe.c:142:21: error: variable has incomplete type 'struct dma_buf_map'
        struct dma_buf_map map;
                           ^
../drivers/gpu/drm/gud/gud_pipe.c:142:9: note: forward declaration of 'struct dma_buf_map'
        struct dma_buf_map map;
               ^
../drivers/gpu/drm/gud/gud_drv.c:22:10: fatal error: 'drm/drm_gem_atomic_helper.h' file not found
#include <drm/drm_gem_atomic_helper.h>
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/gpu/drm/gud/gud_pipe.c:183:4: error: implicit declaration of function 'drm_fb_xrgb8888_to_rgb332' [-Werror,-Wimplicit-function-declaration]
                        drm_fb_xrgb8888_to_rgb332(buf, vaddr, fb, rect);
                        ^
../drivers/gpu/drm/gud/gud_pipe.c:183:4: note: did you mean 'drm_fb_xrgb8888_to_rgb565'?
1 error generated.
../include/drm/drm_format_helper.h:19:6: note: 'drm_fb_xrgb8888_to_rgb565' declared here
void drm_fb_xrgb8888_to_rgb565(void *dst, void *vaddr,
     ^
make[5]: *** [../scripts/Makefile.build:321: drivers/gpu/drm/gud/gud_drv.o] Error 1
make[5]: *** Waiting for unfinished jobs....
../drivers/gpu/drm/gud/gud_pipe.c:187:4: error: implicit declaration of function 'drm_fb_xrgb8888_to_rgb888' [-Werror,-Wimplicit-function-declaration]
                        drm_fb_xrgb8888_to_rgb888(buf, vaddr, fb, rect);
                        ^
../drivers/gpu/drm/gud/gud_pipe.c:187:4: note: did you mean 'drm_fb_xrgb8888_to_rgb565'?
../include/drm/drm_format_helper.h:19:6: note: 'drm_fb_xrgb8888_to_rgb565' declared here
void drm_fb_xrgb8888_to_rgb565(void *dst, void *vaddr,
     ^
3 errors generated.
make[5]: *** [../scripts/Makefile.build:321: drivers/gpu/drm/gud/gud_pipe.o] Error 1
make[4]: *** [../scripts/Makefile.build:588: drivers/gpu/drm/gud] Error 2
make[3]: *** [../scripts/Makefile.build:588: drivers/gpu/drm] Error 2
make[2]: *** [../scripts/Makefile.build:588: drivers/gpu] Error 2
make[2]: *** Waiting for unfinished jobs....
make[1]: *** [/home/andrea/Desktop/Kirisakura_Pantah/Makefile:1948: drivers] Error 2
make[1]: *** Waiting for unfinished jobs....

[LollosoSi]

The idea was using the phone with a GUD display since native DP alt mode is disabled software or hardware side

Extending the display just like that mode would be a dream

[notro]

Ok, that means backporting patches.

First we strip down the challenge by just applying the first 2 GUD patches:
0001-drm-uapi-Add-USB-connector-type.patch
0002-drm-Add-GUD-USB-Display-driver.patch

Then apply these dma-buf patches:
https://github.com/torvalds/linux/commit/01fd30da0474d5528d96a154cb50ce3b0352fd19.patch
https://github.com/torvalds/linux/commit/6619ccf1bb1d0ebb071f758111efa83918b216fc.patch
https://github.com/torvalds/linux/commit/20e76f1a70596590dec32a5d1f598fba04859526.patch

Then these 2 for shmem:
https://github.com/torvalds/linux/commit/49a3f51dfeeecb52c5aa28c5cb9592fe5e39bf95.patch
https://github.com/torvalds/linux/commit/0cf2ef46c6c0f1a0b475a63633706af8194484df.patch

Now we're left with this that I didn't have time to look into:
#include <drm/drm_gem_atomic_helper.h>

Maybe you can just delete the line and see what happens?

If you can't make it work, maybe I have time to look more into it this weekend.

[LollosoSi]

first 3 patches and the last one are ok
4th patch: first part is okay, then I skipped the second. file heap-helpers.c is missing

Kirisakura_Pantah$ patch -p1 < gud/patch4.patch 
patching file drivers/dma-buf/dma-buf.c
Reversed (or previously applied) patch detected!  Assume -R? [n] 
Apply anyway? [n] n
Skipping patch.
1 out of 1 hunk ignored -- saving rejects to file drivers/dma-buf/dma-buf.c.rej
can't find file to patch at input line 124
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c
|index 9f964ca3f59cea..27e54d9c120cd3 100644
|--- a/drivers/dma-buf/heaps/heap-helpers.c
|+++ b/drivers/dma-buf/heaps/heap-helpers.c
--------------------------
File to patch: 
Skip this patch? [y] y
Skipping patch.
2 out of 2 hunks ignored
patching file drivers/gpu/drm/drm_gem_cma_helper.c
Hunk #1 succeeded at 617 (offset -17 lines).
patching file drivers/gpu/drm/drm_gem_shmem_helper.c
patching file drivers/gpu/drm/drm_prime.c
Hunk #1 succeeded at 667 (offset 5 lines).
patching file drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
patching file drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
Hunk #1 succeeded at 77 (offset -5 lines).
patching file drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
patching file drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
Hunk #1 succeeded at 61 (offset -1 lines).
patching file drivers/gpu/drm/tegra/gem.c
Hunk #2 succeeded at 637 (offset -16 lines).
patching file drivers/media/common/videobuf2/videobuf2-dma-contig.c
Hunk #1 succeeded at 76 (offset -5 lines).
Hunk #2 succeeded at 348 (offset -21 lines).
patching file drivers/media/common/videobuf2/videobuf2-dma-sg.c
Hunk #1 succeeded at 295 (offset -5 lines).
Hunk #2 succeeded at 484 (offset -9 lines).
patching file drivers/media/common/videobuf2/videobuf2-vmalloc.c
Hunk #1 succeeded at 314 (offset -4 lines).
Hunk #2 succeeded at 372 (offset -4 lines).
patching file drivers/misc/fastrpc.c
Hunk #1 succeeded at 596 (offset 15 lines).
patching file include/drm/drm_prime.h
patching file include/linux/dma-buf-map.h
patching file include/linux/dma-buf.h
Hunk #1 succeeded at 324 with fuzz 2 (offset 58 lines).
Hunk #2 FAILED at 503.
1 out of 2 hunks FAILED -- saving rejects to file include/linux/dma-buf.h.rej

Same with patch 5

Kirisakura_Pantah$ patch -p1 < gud/patch5.patch 
patching file drivers/dma-buf/dma-buf.c
Hunk #1 succeeded at 1337 (offset 101 lines).
can't find file to patch at input line 83
Perhaps you used the wrong -p or --strip option?
The text leading up to this was:
--------------------------
|diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c
|index 27e54d9c120cd3..e9fb2818f2d4d7 100644
|--- a/drivers/dma-buf/heaps/heap-helpers.c
|+++ b/drivers/dma-buf/heaps/heap-helpers.c
--------------------------
File to patch: 
Skip this patch? [y] 
Skipping patch.
1 out of 1 hunk ignored
patching file drivers/gpu/drm/drm_gem_cma_helper.c
Hunk #2 succeeded at 627 (offset -17 lines).
patching file drivers/gpu/drm/drm_gem_shmem_helper.c
Hunk #2 FAILED at 346.
1 out of 2 hunks FAILED -- saving rejects to file drivers/gpu/drm/drm_gem_shmem_helper.c.rej
patching file drivers/gpu/drm/drm_prime.c
Hunk #1 succeeded at 692 (offset 5 lines).
patching file drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
patching file drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
Hunk #1 succeeded at 91 (offset -5 lines).
patching file drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
patching file drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
Hunk #1 succeeded at 74 (offset -1 lines).
patching file drivers/gpu/drm/tegra/gem.c
Hunk #2 succeeded at 648 (offset -16 lines).
patching file drivers/media/common/videobuf2/videobuf2-dma-contig.c
Hunk #1 succeeded at 625 (offset -23 lines).
Hunk #2 succeeded at 638 (offset -23 lines).
patching file drivers/media/common/videobuf2/videobuf2-dma-sg.c
Hunk #1 succeeded at 571 (offset -9 lines).
Hunk #2 succeeded at 584 (offset -9 lines).
patching file drivers/media/common/videobuf2/videobuf2-vmalloc.c
Hunk #1 succeeded at 386 (offset -4 lines).
patching file include/drm/drm_prime.h
patching file include/linux/dma-buf-map.h
patching file include/linux/dma-buf.h
Hunk #1 FAILED at 267.
Hunk #2 FAILED at 504.
2 out of 2 hunks FAILED -- saving rejects to file include/linux/dma-buf.h.rej

Patch 6 has some fails but didn't prompt for anything:

Kirisakura_Pantah$ patch -p1 < gud/patch6.patch 
patching file Documentation/gpu/todo.rst
Hunk #1 succeeded at 449 (offset -1 lines).
patching file drivers/gpu/drm/Kconfig
Hunk #1 succeeded at 248 (offset 16 lines).
Hunk #2 succeeded at 269 (offset 16 lines).
patching file drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
patching file drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.h
patching file drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
Hunk #2 FAILED at 221.
1 out of 2 hunks FAILED -- saving rejects to file drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c.rej
patching file drivers/gpu/drm/amd/amdgpu/amdgpu_object.h
Hunk #1 succeeded at 101 (offset 1 line).
patching file drivers/gpu/drm/ast/ast_cursor.c
patching file drivers/gpu/drm/ast/ast_drv.h
Hunk #2 succeeded at 133 (offset 1 line).
patching file drivers/gpu/drm/drm_gem.c
Hunk #2 FAILED at 1208.
1 out of 2 hunks FAILED -- saving rejects to file drivers/gpu/drm/drm_gem.c.rej
patching file drivers/gpu/drm/drm_gem_cma_helper.c
Hunk #2 succeeded at 529 with fuzz 1.
patching file drivers/gpu/drm/drm_gem_shmem_helper.c
Hunk #6 FAILED at 355.
Hunk #7 succeeded at 367 (offset 1 line).
Hunk #8 succeeded at 377 (offset 1 line).
1 out of 8 hunks FAILED -- saving rejects to file drivers/gpu/drm/drm_gem_shmem_helper.c.rej
patching file drivers/gpu/drm/drm_gem_vram_helper.c
Hunk #2 succeeded at 114 (offset 1 line).
Hunk #3 FAILED at 379.
Hunk #4 succeeded at 460 (offset 45 lines).
Hunk #5 FAILED at 426.
Hunk #6 succeeded at 520 (offset 45 lines).
Hunk #7 succeeded at 611 with fuzz 1 (offset 45 lines).
Hunk #8 succeeded at 866 (offset 28 lines).
2 out of 8 hunks FAILED -- saving rejects to file drivers/gpu/drm/drm_gem_vram_helper.c.rej
patching file drivers/gpu/drm/etnaviv/etnaviv_drv.h
Hunk #1 FAILED at 51.
1 out of 1 hunk FAILED -- saving rejects to file drivers/gpu/drm/etnaviv/etnaviv_drv.h.rej
patching file drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
Hunk #1 succeeded at 22 with fuzz 1.
patching file drivers/gpu/drm/lima/lima_gem.c
patching file drivers/gpu/drm/lima/lima_sched.c
patching file drivers/gpu/drm/mgag200/mgag200_mode.c
Hunk #2 succeeded at 1566 (offset 14 lines).
patching file drivers/gpu/drm/nouveau/Kconfig
patching file drivers/gpu/drm/nouveau/nouveau_bo.h
Hunk #1 FAILED at 39.
1 out of 1 hunk FAILED -- saving rejects to file drivers/gpu/drm/nouveau/nouveau_bo.h.rej
patching file drivers/gpu/drm/nouveau/nouveau_gem.c
Hunk #2 FAILED at 178.
1 out of 2 hunks FAILED -- saving rejects to file drivers/gpu/drm/nouveau/nouveau_gem.c.rej
patching file drivers/gpu/drm/nouveau/nouveau_gem.h
Hunk #1 succeeded at 35 (offset -2 lines).
patching file drivers/gpu/drm/nouveau/nouveau_prime.c
patching file drivers/gpu/drm/panfrost/panfrost_perfcnt.c
patching file drivers/gpu/drm/qxl/qxl_display.c
Hunk #2 succeeded at 583 (offset 1 line).
Hunk #3 succeeded at 599 (offset 1 line).
Hunk #4 succeeded at 618 (offset 1 line).
Hunk #5 succeeded at 1147 (offset 6 lines).
Hunk #6 succeeded at 1164 (offset 6 lines).
patching file drivers/gpu/drm/qxl/qxl_draw.c
patching file drivers/gpu/drm/qxl/qxl_drv.h
Hunk #3 FAILED at 82.
Hunk #4 succeeded at 339 (offset 1 line).
Hunk #5 succeeded at 448 (offset 1 line).
1 out of 5 hunks FAILED -- saving rejects to file drivers/gpu/drm/qxl/qxl_drv.h.rej
patching file drivers/gpu/drm/qxl/qxl_object.c
patching file drivers/gpu/drm/qxl/qxl_object.h
Hunk #1 succeeded at 87 with fuzz 1 (offset 24 lines).
patching file drivers/gpu/drm/qxl/qxl_prime.c
patching file drivers/gpu/drm/radeon/radeon.h
Hunk #1 succeeded at 510 (offset 1 line).
patching file drivers/gpu/drm/radeon/radeon_gem.c
Hunk #2 FAILED at 41.
Hunk #3 FAILED at 236.
2 out of 3 hunks FAILED -- saving rejects to file drivers/gpu/drm/radeon/radeon_gem.c.rej
patching file drivers/gpu/drm/radeon/radeon_prime.c
patching file drivers/gpu/drm/rockchip/rockchip_drm_gem.c
Hunk #1 succeeded at 518 (offset -14 lines).
patching file drivers/gpu/drm/rockchip/rockchip_drm_gem.h
patching file drivers/gpu/drm/tiny/cirrus.c
patching file drivers/gpu/drm/tiny/gm12u320.c
Hunk #1 succeeded at 249 (offset -1 lines).
Hunk #2 succeeded at 264 (offset -1 lines).
Hunk #3 succeeded at 321 (offset -1 lines).
patching file drivers/gpu/drm/udl/udl_modeset.c
Hunk #2 succeeded at 297 with fuzz 1.
Hunk #3 succeeded at 337 (offset 2 lines).
patching file drivers/gpu/drm/vboxvideo/vbox_mode.c
patching file drivers/gpu/drm/vc4/vc4_bo.c
Hunk #1 succeeded at 767 (offset -18 lines).
patching file drivers/gpu/drm/vc4/vc4_drv.h
Hunk #1 succeeded at 811 with fuzz 2 (offset 5 lines).
patching file drivers/gpu/drm/vgem/vgem_drv.c
Hunk #1 succeeded at 357 (offset -4 lines).
patching file drivers/gpu/drm/vkms/vkms_plane.c
Hunk #2 FAILED at 148.
Hunk #3 FAILED at 166.
2 out of 3 hunks FAILED -- saving rejects to file drivers/gpu/drm/vkms/vkms_plane.c.rej
patching file drivers/gpu/drm/vkms/vkms_writeback.c
Hunk #2 succeeded at 8 with fuzz 2 (offset -1 lines).
Hunk #3 FAILED at 68.
Hunk #4 FAILED at 90.
2 out of 4 hunks FAILED -- saving rejects to file drivers/gpu/drm/vkms/vkms_writeback.c.rej
patching file drivers/gpu/drm/xen/xen_drm_front_gem.c
Hunk #1 succeeded at 275 (offset -15 lines).
patching file drivers/gpu/drm/xen/xen_drm_front_gem.h
patching file include/drm/drm_gem.h
patching file include/drm/drm_gem_cma_helper.h
Hunk #1 FAILED at 103.
1 out of 1 hunk FAILED -- saving rejects to file include/drm/drm_gem_cma_helper.h.rej
patching file include/drm/drm_gem_shmem_helper.h
patching file include/drm/drm_gem_vram_helper.h
Hunk #3 succeeded at 51 (offset 1 line).
Hunk #4 succeeded at 100 (offset 3 lines).

Commenting out #include <drm/drm_gem_atomic_helper.h> and compiling produces:

../drivers/dma-buf/dma-buf.c:1299:5: error: conflicting types for 'dma_buf_vmap'
int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
    ^
../include/linux/dma-buf.h:625:7: note: previous declaration is here
void *dma_buf_vmap(struct dma_buf *);
      ^
../drivers/dma-buf/dma-buf.c:1342:6: error: conflicting types for 'dma_buf_vunmap'
void dma_buf_vunmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
     ^
../include/linux/dma-buf.h:626:6: note: previous declaration is here
void dma_buf_vunmap(struct dma_buf *, void *vaddr);
     ^
  AR      drivers/i2c/muxes/built-in.a
2 errors generated.
make[3]: *** [../scripts/Makefile.build:321: drivers/dma-buf/dma-buf.o] Error 1
make[3]: *** Waiting for unfinished jobs....
  CC      drivers/media/mc/mc-devnode.o
  AR      drivers/ptp/built-in.a
../drivers/dma-buf/heaps/samsung/heap_dma_buf.c:470:10: error: incompatible function pointer types initializing 'int (*)(struct dma_buf *, struct dma_buf_map *)' with an expression of type 'void *(struct dma_buf *)' [-Wincompatible-function-pointer-types]
        .vmap = samsung_heap_vmap,
                ^~~~~~~~~~~~~~~~~
1 error generated.
make[5]: *** [../scripts/Makefile.build:321: drivers/dma-buf/heaps/samsung/heap_dma_buf.o] Error 1
make[4]: *** [../scripts/Makefile.build:588: drivers/dma-buf/heaps/samsung] Error 2
make[3]: *** [../scripts/Makefile.build:588: drivers/dma-buf/heaps] Error 2
make[2]: *** [../scripts/Makefile.build:588: drivers/dma-buf] Error 2
make[2]: *** Waiting for unfinished jobs....
  CC      drivers/gpu/drm/gud/gud_connector.o
  CC      drivers/input/keyboard/gpio_keys.o
  CC      drivers/scsi/ufs/ufshcd-pci.o
  CC      drivers/i2c/i2c-boardinfo.o
  CC      drivers/i2c/i2c-core-base.o
  CC      drivers/rtc/class.o
  AR      drivers/i3c/built-in.a
  CC      drivers/net/wireguard/peerlookup.o
  CC      drivers/usb/core/file.o
  CC      drivers/net/wireguard/allowedips.o
  CC      drivers/usb/core/buffer.o
../drivers/gpu/drm/gud/gud_drv.c:367:16: error: use of undeclared identifier 'drm_gem_simple_display_pipe_prepare_fb'; did you mean 'drm_gem_fb_simple_display_pipe_prepare_fb'?
        .prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
                      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                      drm_gem_fb_simple_display_pipe_prepare_fb
../include/drm/drm_gem_framebuffer_helper.h:49:5: note: 'drm_gem_fb_simple_display_pipe_prepare_fb' declared here
int drm_gem_fb_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
    ^
../drivers/gpu/drm/gud/gud_drv.c:437:33: error: passing 'const struct drm_driver *' to parameter of type 'struct drm_driver *' discards qualifiers [-Werror,-Wincompatible-pointer-types-discards-qualifiers]
        gdrm = devm_drm_dev_alloc(dev, &gud_drm_driver, struct gud_device, drm);
                                       ^~~~~~~~~~~~~~~
../include/drm/drm_drv.h:631:41: note: expanded from macro 'devm_drm_dev_alloc'
        ((type *) __devm_drm_dev_alloc(parent, driver, sizeof(type), \
                                               ^~~~~~
../include/drm/drm_drv.h:601:70: note: passing argument to parameter 'driver' here
void *__devm_drm_dev_alloc(struct device *parent, struct drm_driver *driver,
                                                                     ^
2 errors generated.
make[5]: *** [../scripts/Makefile.build:321: drivers/gpu/drm/gud/gud_drv.o] Error 1
make[5]: *** Waiting for unfinished jobs...

and

./drivers/media/common/videobuf2/videobuf2-vmalloc.c:378:32: error: too many arguments to function call, expected 1, have 2
        ret = dma_buf_vmap(buf->dbuf, &map);
              ~~~~~~~~~~~~            ^~~~
../include/linux/dma-buf.h:625:7: note: 'dma_buf_vmap' declared here
void *dma_buf_vmap(struct dma_buf *);
      ^
1 error generated.
  CC [M]  drivers/usb/host/xhci-exynos.o
make[5]: *** [../scripts/Makefile.build:321: drivers/media/common/videobuf2/videobuf2-vmalloc.o] Error 1
make[4]: *** [../scripts/Makefile.build:588: drivers/media/common/videobuf2] Error 2
make[3]: *** [../scripts/Makefile.build:588: drivers/media/common] Error 2
make[3]: *** Waiting for unfinished jobs...

[notro]

Ugh, that's a rabbit hole I don't want to dive into. I'll see if I can backport the driver instead. It looks like I have an early version of the driver that was developed on <=v5.10.

[LollosoSi]

No problem, take your time

[notro]

Applying these patches compiles for me on v5.10.197.

drm: document drm_mode_get_connector
0001-drm-uapi-Add-USB-connector-type.patch
0002-drm-Add-GUD-USB-Display-driver.patch
drm/gud: Backport driver to v5.10

I haven't tried that it actually works though.

[LollosoSi]

fbcon is unavailable, looks like I should recompile the kernel to add it

[LollosoSi]

I tried compiling a few times with some config for fbcon but the only thing I could get is bootloop

[LollosoSi]

Hi, just wanted to let you know I'm still on it.

At the moment, purchased pieces to build this it's the UART interface specific for the Pixel 7 and previous.
Hopefully we can learn something more from it

[srmji]

Any update on this?

[LollosoSi]

Any update on this?

Nope, not yet. Anyone is free to tackle this challenge