Andrew Krieger
09ce41899a
Testing shows that, with the newly set parameters (bs=64, bc=512, ml=32, ll=1, raw=true), each byte of data contributes approximately 0.58 bits of min-entropy on the rpi3 and 0.5 bits on qemu-arm64. A safety factor of 0.9 gives us 0.50 * 0.9 * 1000 == 450 bits of entropy per 1000 bytes of random data. This adds about 40ms to boot on rpi3 and 30ms on qemu-arm64. Jitterentropy doesn't work on x86 as of this commit (the timer isn't ready during early boot), so there should be negligible slowdown on x86. On rpi3, about 10ms is due to the actual entropy draw from jitterentropy, and 30ms is due to the startup testing built into jitterentropy. Once we have entropy source testing in the kernel, we can replace the jitterentropy testing time to reduce blocking during the single-threaded, pre-VMM boot phase. Change-Id: Ibf258412c7947e4e828926a88c0897f22199d7d3
Magenta
Magenta is the core platform that powers the Fuchsia OS. Magenta is composed of a microkernel (source in kernel/...) as well as a small set of userspace services, drivers, and libraries (source in system/...) necessary for the system to boot, talk to hardware, load userspace processes and run them, etc. Fuchsia builds a much larger OS on top of this foundation.
The canonical Magenta Git repository is located at: https://fuchsia.googlesource.com/magenta
A read-only mirror of the code is present at: https://github.com/fuchsia-mirror/magenta
The Magenta Kernel provides syscalls to manage processes, threads, virtual memory, inter-process communication, waiting on object state changes, and locking (via futexes).
Currently there are some temporary syscalls that have been used for early bringup work, which will be going away in the future as the long term syscall API/ABI surface is finalized. The expectation is that there will be about 100 syscalls.
Magenta syscalls are generally non-blocking. The wait_one, wait_many port_wait and thread sleep being the notable exceptions.
This page is a non-comprehensive index of the magenta documentation.