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dev:devmanual [2006/07/16 09:35] stockholm |
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| ==== How can I get Etherboot to boot a Cardbus (PCMICA) or a USB NIC? ==== | ==== How can I get Etherboot to boot a Cardbus (PCMICA) or a USB NIC? ==== | ||
| + | Cardbus (PCMCIA) and USB NICs are interfaced to the CPU through their respective bus controllers. Before Etherboot can address the registers and memory on these NICs, it must initialise the bus controller appropriately. In Linux this is done by the PCMCIA and USB subsystems. In Etherboot, all this must be done by the code in the ROM. What needs to be written is a subsystem like the PCI subsystem in Etherboot. Volunteers are most welcome. | ||
| ===== Writing an EtherBoot Driver ===== | ===== Writing an EtherBoot Driver ===== | ||
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| ==== Preliminaries ==== | ==== Preliminaries ==== | ||
| + | So Etherboot does not have a driver for your network adapter and you want to write one. You should have a good grasp of C, especially with respect to bit operations. You should also understand hardware interfacing concepts, such as the fact that the x86 architecture has a separate I/O space and that peripherals are commanded with ''out'' instructions and their status read with ''in'' instructions. A microprocessor course such as those taught in engineering or computer science curricula would have given you the fundamentals. (Note to educators and students in computer engineering: An Etherboot driver should be feasible as a term project for a final year undergraduate student. I estimate about 40 hours of work is required. I am willing to be a source of technical advice.) | ||
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| + | Next you need a development machine. This can be your normal Linux machine. You need another test machine, networked to the development machine. This should be a machine you will not feel upset rebooting very often. So the reset button should be in working condition. :-) It should have a floppy drive on it but does not need a hard disk, and in fact a hard disk will slow down rebooting. Alternatively, it should have another network adapter which can netboot; see discussion further down. Needless to say, you need a unit of the adapter you are trying to write a driver for. You should gather all the documentation you can find for the hardware, from the manufacturer and other sources. | ||
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| ==== Background information ==== | ==== Background information ==== | ||
| ==== Structure of the code ==== | ==== Structure of the code ==== | ||
