Date: Sun, 27 Oct 2019 23:29:56 +0100 From: Milan Obuch <freebsd-hackers@dino.sk> To: Oliver Pinter <oliver.pinter@hardenedbsd.org> Cc: freebsd-hackers@freebsd.org Subject: Re: UART driver as kld - how? Message-ID: <20191027232956.28b11772@zeta.dino.sk> In-Reply-To: <CAPQ4ffuoHRFghwo=okFoNVHw9TYdwFw_wgUxa5_rm6FqjsNVsg@mail.gmail.com> References: <20191027214209.712d62ca@zeta.dino.sk> <CAPQ4ffuoHRFghwo=okFoNVHw9TYdwFw_wgUxa5_rm6FqjsNVsg@mail.gmail.com>
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On Sun, 27 Oct 2019 22:52:10 +0100 Oliver Pinter <oliver.pinter@hardenedbsd.org> wrote: > On Sunday, October 27, 2019, Milan Obuch <freebsd-hackers@dino.sk> > wrote: > > > Hi, > > > > I am trying to create a driver for Xilinx' AXI UART Lite IP core. I > > can't find a way to do it as kld module. I started with > > uart_dev_cdnc.c, but I can't see how it is hooked into the kernel - > > or, better formulated, how can I created kld loadable module. As > > Zynq has uart_dev_cdnc driver for its PS UART, all necessary files > > are compiled into kernel, but how can I extend those modules tables > > to work with new driver too? > > > > You can ask why I want it this way, if I can put this into kernel... > > simply this would make development awkward - every change would mean > > recompile everything (or at least relinking kernel) and reboot. With > > kld, I can just rebuild the module, reinstall it, unload old/load > > new version and test. Other thing is, for any IP core I must first > > load hw design into PL part (FPGA bitstream, actually), there is > > simply no device without this step performed. > > > > Did anybody already create something similar? Any help/hint/pointer > > appreciated... > > > https://github.com/freebsd/freebsd/tree/master/share/examples/kld > Hi, my problem is somewhere else - I am able to build kld, load and unload it, but in all uart_dev_xxxx.c files I saw there are no attach and detach function, so there must be something more to do. On the other side, uart_core.o is already present in kernel, but how should I make it work with newly loaded module? uart_bus_fdt.o is linked in kernel too, and there are attach and detach function, but how can my tables be added in list for it? Regards, Milan
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