xray v1: an X-ray of an Android phone before porting
xray collects over adb what you need to know about an Android phone before porting it: SoC, partitions, fstab and kernel. No root, Android 2.2 to 4.2.
Blog
Notes on Android ports, kernels, recoveries and hardware reverse engineering.
Persistent TWRP on the LG Optimus F3 P659H: a new Loki target
The P659H rejected TWRP with “boot certification verify”. I analyzed its aboot, added a Loki target, and obtained persistent recovery.
Kernel 3.4 for the LG L3 (E400): from a phone that rebooted itself to CM10.1 with GPS, sensors and camera
The LG L3 (MSM7225A) shipped with kernel 2.6.38. Moving it to 3.4 for Android 4.2.2 was a chain of silent reboots, nearly all caused by the modem.
The LG G2 Mini doesn't use LK: unlocking a Tegra 4i with nvflash
The G2 Mini (D625) is a Tegra 4i, not a MediaTek LK phone: unlocking works differently, with its own low-level recovery mode and flashing tool.
adb over Wi-Fi, and why it drops right when you need it most
adb tcpip lets you debug over Wi-Fi while USB is in host mode, but everything depends on the network: a mistake of mine shows how the link drops.
QApp: testing a ROM without guessing
Born to confirm a worn-out battery on the LG D625. Now it runs automatic tests on Android 2.2+ with a report that survives a reboot.
Screenshotting Android 2.3 without screencap
Gingerbread has no screencap. Read /dev/graphics/fb0 directly and use the panel's real stride, which almost never matches the visible width.
The C660's battery: what you can measure without a fuel gauge
The LG C660 has no battery gauge chip: voltage reaches the OS filtered from the modem in 17 mV steps. What you can conclude with that, and what not.
USB OTG on the LG C660: what I measured and why it does not work
I enabled the 2.6.35 kernel's USB host, forced host mode and measured the PHY: with a flash drive or mouse, D+ and D- never move.
What doesn't exist in the Android 2.3 shell (and what does, against what I believed)
input tap, swipe and am force-stop don't exist on Gingerbread, but the shell's $((...)) arithmetic does. I checked it on a real phone.
USB OTG on the LG L3 (E400): host mode with a software switch
The L3's stock kernel already had USB host. Missing: mounting the disk and a switch to force host mode, since the ID pin never reaches the CPU.
A reboot at exactly 612 seconds
The LG L3 on kernel 3.4 reboots by itself, no panic, at 609–616 s of uptime; on 2.6.38 it doesn't. What I ruled out and what's still open.
A 3.4.5 kernel for the Huawei Y220-U05: 26 commits from a donor tree to a stable Gingerbread
The Y220-U05 (MT6572) runs a kernel from a donor tree. What had to be fixed: boot, Wi-Fi, camera, power-off charging and the hotspot.
Platform patches or device tree: why I choose HALs and shims
My rule in ports: don't patch Android's platform code; solve hardware differences in the device tree with HALs and shims. Three real examples.
One patch, three phones: MediaTek's LK bootloader
One LK bootloader patch, with tweaks, worked on three LG phones. The first version seemed fine and left the phone in a boot loop.
Testing the Huawei Y220-U05 kernel without risking the ROM: TWRP first
Before booting the Y220-U05's Android with my own kernel I tried each version as a recovery. How I built that test bench and what it taught me.