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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /Documentation/mips/GT64120.README
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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+README for arch/mips/gt64120 directory and subdirectories
+
+Jun Sun, jsun@mvista.com or jsun@junsun.net
+01/27, 2001
+
+MOTIVATION
+----------
+
+Many MIPS boards share the same system controller (or CPU companian chip),
+such as GT-64120. It is highly desirable to let these boards share
+the same controller code instead of duplicating them.
+
+This directory is meant to hold all MIPS boards that use GT-64120 or GT-64120A.
+
+
+HOW TO ADD A BOARD
+------------------
+
+. Create a subdirectory include/asm/gt64120/<board>.
+
+. Create a file called gt64120_dep.h under that directory.
+
+. Modify include/asm/gt64120/gt64120.h file to include the new gt64120_dep.h
+ based on config options. The board-dep section is at the end of
+ include/asm/gt64120/gt64120.h file. There you can find all required
+ definitions include/asm/gt64120/<board>/gt64120_dep.h file must supply.
+
+. Create a subdirectory arch/mips/gt64120/<board> directory to hold
+ board specific routines.
+
+. The GT-64120 common code is supplied under arch/mips/gt64120/common directory.
+ It includes:
+ 1) arch/mips/gt64120/pci.c -
+ common PCI routine, include the top-level pcibios_init()
+ 2) arch/mips/gt64120/irq.c -
+ common IRQ routine, include the top-level do_IRQ()
+ [This part really belongs to arch/mips/kernel. jsun]
+ 3) arch/mips/gt64120/gt_irq.c -
+ common IRQ routines for GT-64120 chip. Currently it only handles
+ the timer interrupt.
+
+. Board-specific routines are supplied under arch/mips/gt64120/<board> dir.
+ 1) arch/mips/gt64120/<board>/pci.c - it provides bus fixup routine
+ 2) arch/mips/gt64120/<board>/irq.c - it provides enable/disable irqs
+ and board irq setup routine (irq_setup)
+ 3) arch/mips/gt64120/<board>/int-handler.S -
+ The first-level interrupt dispatching routine.
+ 4) a bunch of other "normal" stuff (setup, prom, dbg_io, reset, etc)
+
+. Follow other "normal" procedure to modify configuration files, etc.
+
+
+TO-DO LIST
+----------
+
+. Expand arch/mips/gt64120/gt_irq.c to handle all GT-64120 interrupts.
+ We probably need to introduce GT_IRQ_BASE in board-dep header file,
+ which is used the starting irq_nr for all GT irqs.
+
+ A function, gt64120_handle_irq(), will be added so that the first-level
+ irq dispatcher will call this function if it detects an interrupt
+ from GT-64120.
+
+. More support for GT-64120 PCI features (2nd PCI bus, perhaps)
+