Msm8953 For Arm64 Driver High Quality «100% RELIABLE»

Here’s a technical review of MSM8953 (also known as Snapdragon 625/626) support for arm64 drivers, focusing on the mainline Linux kernel and Android common kernel perspectives.

2. Kernel support (upstream vs vendor)

• Mainline Linux historically lags in full MSM support; many Qualcomm-specific drivers live in vendor trees (Qualcomm/Exynos/msm branches) and Android common kernels.
• For ARM64 builds, use a kernel with CONFIG_SOC_QCOM and MSM platform drivers enabled.
• Typical kernel base: Android common kernel (e.g., msm-4.4 or msm-4.9, later 4.14/4.19) or Qualcomm's forks. Upstream support has improved, but GPU, modem, and some power-management pieces often remain vendor-specific.

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Recommendation for Arm64 Driver Development

If your goal is mainline Linux on MSM8953 (e.g., postmarketOS, bootlin, or generic ARM64 distro):

✅ Good enough for:

• Headless server / IoT (UART, I2C, SPI, USB, eMMC/SD).
• Basic framebuffer console (simplefb).
• Kernel debugging / learning ARM64 platform support.

❌ Not ready for:

• Full GUI / graphics acceleration without downstream glue.
• Phone functionality (calls, modem, audio routing, sensors).
• Production multimedia product without major out-of-tree patches.

Part 6: Building an MSM8953 ARM64 Driver from Source (Step-by-Step)

Let’s say you need to rebuild the WiFi driver for a custom ARM64 kernel.

Prerequisites:

• AArch64 cross-compiler: aarch64-linux-android- (from NDK) or aarch64-linux-gnu-
• Kernel source: version 4.9 or 4.14 (backported)

Steps:

1. Export environment:

   export ARCH=arm64
   export CROSS_COMPILE=aarch64-linux-android-
   make msm8953_defconfig
   make -j8
   

2. Build WiFi module:

   cd drivers/staging/qcacld-3.0/
   make -C /path/to/kernel M=$(pwd) modules
   

3. The output is wlan.ko. Check its architecture: msm8953 for arm64 driver

   file wlan.ko
   # Output: ELF 64-bit LSB relocatable, ARM aarch64
   

4. Sign the module (if using Android Verified Boot):

   /external/avb/avbtool add_hash_footer --image wlan.ko
   

5. Push to device:

   adb push wlan.ko /vendor/lib/modules/
   adb shell insmod /vendor/lib/modules/wlan.ko
   

Error handling: If you see Required key not available, disable CONFIG_MODULE_SIG_FORCE. Here’s a technical review of MSM8953 (also known

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5.2 LineageOS Kernel (most active)

• Git: https://github.com/LineageOS/android_kernel_google_msm-4.9
• Look for commits tagged msm8953 – includes backported ARM64 fixes for Spectre/Meltdown.

2.1 Adreno 506 GPU (DRM/MSM Driver)

The graphics driver is the most critical for ARM64. The open-source msm DRM driver (part of the mainline Linux kernel) supports Adreno 5xx series. However, userspace needs the Freedreno Vulkan driver (Turnip) or Qualcomm’s proprietary kgsl driver.

• ARM64 status: ✅ Fully working
• Required blobs:
  kgsl (kernel) + adreno firmware (a530_* files) + libGLESv2_adreno.so (64-bit).
  Devices like Redmi Note 4 (mido) use 64-bit Adreno blobs from Xiaomi’s Mi A1 (tissot) or from SDM660.
• Common issues:
  Missing 64-bit egl.cfg or incorrect symlinks to /vendor/lib64/egl/

Security and firmware considerations

• Keep firmware blobs up to date; mismatched kernel drivers and firmware may crash devices.
• Check for signed firmware requirements and secure boot implications if modifying low-level firmware/bootloaders.

2.3 I/O and Storage (UFS/eMMC + SDHCI)

MSM8953 uses either eMMC 5.1 or SDIO for storage. The driver is sdhci-msm.c.

• ARM64 status: ✅ Perfect – fully open source in kernel.
• No proprietary blobs needed.