46 lines
2.5 KiB
Plaintext
46 lines
2.5 KiB
Plaintext
This version of NetBSD now includes support for the 68040. This version
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should support both the 68030 and 68040 processors with a single kernel.
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The config option FPSP will include the full Floating Point Support
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Package to provide emulation of the floating point instructions not
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implemented by the 68040. If the FPSP option is not used, then a
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dummy file is included that will cause a panic if any FPSP routine
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is called. This allows building a smaller kernel specifically for
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the 68030.
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The FPSP is provided as an object file. The FPSP was ported to gas by
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Eric Norum (eric@skatter.usask.ca) and is available by anonymous ftp from:
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ftp.usask.ca /pub/software/fpsp/fpsp_gas.tar.gz
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Note: Motorola still holds the title and all rights to the FPSP.
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Support for the Progressive Peripherals Incorporated Zeus SCSI interface
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is also included. If the configuration file does not include support for
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the A3000/A2091/GVP11 drivers, then including the "zeusscsi" driver will
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configure the driver to use the sd (disk) and st (tape) devices. If any
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of the A3000/A2091/GVP11 drivers are configured, then including the zeusscsi
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driver will be configured to use a second set of scsi devices: rz (disk)
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and tz (tape). The rz and tz devices have different major device numbers:
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rz - 5 = block, 9 = character
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tz - 8 = block, 23 = character
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WARNING: since the PPI Zeus SCSI uses the level 6 interrupt, the kernel
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must be compiled with the splbio() macro defined as spl6(). If not,
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then then random kernel hangs will occur. One bad side effect of changing
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splbio() is that it will also block the clock interrupts, which can
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result in incorrect timing. The 53C710 driver (siop.c) also includes
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support the the CSA Magnum 40, but this has not been tested yet.
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The 68040 MMU implementation is not optimal at this time. It was added
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in a manner to fit in with the current 68030 MMU setup without needing
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to completely rewrite the MMU routines. The existing 68030 MMU layout
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was implemented using a two level table: a segment table, and a page
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table. The 68040 MMU can only use a three level table. To simulate a
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two level table, the top level descriptor table is set up and the full
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level 2 descriptor table is allocated and used as the "segment" table.
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This results in 9 pages, or 72K bytes, being allocated for the initial
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page table for each process.
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The reboot command does not work for some reason. It appears to do the
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reset instruction, but doesn't seem to do anything after that.
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Michael Hitch
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