Why Develop Cross-Tools?
We have mentioned little about our protected-mode software generation mechanism in previous articles. In this article, we describe our set of tools that allows us to port 386BSD. Since we don't have 386BSD to generate 386BSD (yet), we must use another UNIX host to run the tools and generate protected-mode software; this "cross" mode operation is part of the means by which we bootstrap 386BSD. In our case, the cross-host that runs the software generating 386 code isn't even a 386!
Because the computer we use to generate the software is not the one that runs it, we will need a means to load files and program over Ethernet and serial lines to the target 386 system. We will then focus on proving GCC itself valid for cross-support purposes. The mechanisms used for this "first assault" will be of great importance until we have developed a stable native environment. Careful preparation in this area will allow us to weather the blinding "blizzards" of bugs which will inevitably arise on our way to the top.
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