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Maybe read this whitepaper: https://www.netbsd.org/gallery/presentations/justin/2015_AsiaBSDCon/justincormack-abc2015.pdf https://www.netbsd.org/gallery/presen

Maybe read this whitepaper: https://www.netbsd.org/gallery/presentations/justin/2015_AsiaBSDCon/justincormack-abc2015.pdf https://www.netbsd.org/gallery/presentations/justin/2015_Asi... “ The rump kernel has been used as a way to supply device drivers in other new operating systems, which do not yet have a full set of device drivers. For example, Genode[4] is a framework for building microkernel operating sys- tems using the L4 family of microkernels. Genode uses the rump kernel to provide file system support, so that it does not have to develop its own file systems.” Here’s a 362 page dissertation on rump kernels which has a netbsd focus: http://lib.tkk.fi/Diss/2012/isbn9789526049175/isbn9789526049175.pdf http://lib.tkk.fi/Diss/2012/isbn9789526049175/isbn9789526049... There’s also the Wikipedia entry. https://en.m.wikipedia.org/wiki/Rump_kernel https://en.m.wikipedia.org/wiki/Rump_kernel

rjsw 5y ago
That isn't how device drivers are used in NetBSD though, it is a different way of compiling them for other targets.
- mapgrep 5y ago
  From the white paper published on netbsd.org: “ An implementation that does this ships with NetBSD, allowing the NetBSD drivers to be run in NetBSD userspace… The first major PCI driver developed was the In- tel Centrino 7260 driver developed for NetBSD and OpenBSD by Antti Kantee. The commit message said “This is probably the world’s first Canadian cross device driver: it was created for OpenBSD by writing and port- ing a NetBSD driver which was developed in a rump ker- nel in Linux userspace.”[13] Further, just another example, from page 149 in the dissertation is an extended many page discussion of how the rump kernel was used to provide usb support in netbsd. http://lib.tkk.fi/Diss/2012/isbn9789526049175/isbn9789526049175.pdf http://lib.tkk.fi/Diss/2012/isbn9789526049175/isbn9789526049... “ We implemented a host controller called ugenhc. When the kernel’s device autocon- figuration subsystem calls the ugenhc driver to probe the device, the ugenhc driver tries to open /dev/ugen on the host. If the open is successful, the host kernel has attached a device to the respective ugen instance and ugenhc can return a successful match. Next, the ugenhc driver is attached in the rump kernel, along with a USB bus and a USB root hub. The root hub driver explores the bus to see which devices are connected to it, causing the probes to be delivered first to ugenhc and through /dev/ugen to the host kernel and finally to the actual hardware. Figure 3.24 con- tains a “dmesg” of a server with four ugenhc devices configured and one USB mass media attached.” ¯\_(ツ)_/¯
  - rjsw 5y ago
    > ¯\_(ツ)_/¯ UTSL. The author used rump to develop the drivers, it isn't used to run them in a production NetBSD kernel.
- floatboth 5y ago
  But running on other targets is exactly what people are excited about?

rjsw 5y ago

That isn't how device drivers are used in NetBSD though, it is a different way of compiling them for other targets.

mapgrep 5y ago
From the white paper published on netbsd.org: “ An implementation that does this ships with NetBSD, allowing the NetBSD drivers to be run in NetBSD userspace… The first major PCI driver developed was the In- tel Centrino 7260 driver developed for NetBSD and OpenBSD by Antti Kantee. The commit message said “This is probably the world’s first Canadian cross device driver: it was created for OpenBSD by writing and port- ing a NetBSD driver which was developed in a rump ker- nel in Linux userspace.”[13] Further, just another example, from page 149 in the dissertation is an extended many page discussion of how the rump kernel was used to provide usb support in netbsd. http://lib.tkk.fi/Diss/2012/isbn9789526049175/isbn9789526049175.pdf http://lib.tkk.fi/Diss/2012/isbn9789526049175/isbn9789526049... “ We implemented a host controller called ugenhc. When the kernel’s device autocon- figuration subsystem calls the ugenhc driver to probe the device, the ugenhc driver tries to open /dev/ugen on the host. If the open is successful, the host kernel has attached a device to the respective ugen instance and ugenhc can return a successful match. Next, the ugenhc driver is attached in the rump kernel, along with a USB bus and a USB root hub. The root hub driver explores the bus to see which devices are connected to it, causing the probes to be delivered first to ugenhc and through /dev/ugen to the host kernel and finally to the actual hardware. Figure 3.24 con- tains a “dmesg” of a server with four ugenhc devices configured and one USB mass media attached.” ¯\_(ツ)_/¯
- rjsw 5y ago
  > ¯\_(ツ)_/¯ UTSL. The author used rump to develop the drivers, it isn't used to run them in a production NetBSD kernel.
floatboth 5y ago
But running on other targets is exactly what people are excited about?