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      2 # $NetBSD: fpsp.doc,v 1.2 2007/04/29 20:23:35 msaitoh Exp $
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      4 
      5 #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      6 # MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
      7 # M68000 Hi-Performance Microprocessor Division
      8 # M68060 Software Package Production Release 
      9 # 
     10 # M68060 Software Package Copyright (C) 1993, 1994, 1995, 1996 Motorola Inc.
     11 # All rights reserved.
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     14 # To the maximum extent permitted by applicable law,
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     31 # SOFTWARE so long as this entire notice is retained without alteration
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     36 #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     37 
     38 68060 FLOATING-POINT SOFTWARE PACKAGE (Kernel version)
     39 -------------------------------------------------------
     40 
     41 The file fpsp.sa contains the 68060 Floating-Point Software
     42 Package. This package is essentially a set of exception handlers
     43 that can be integrated into an operating system. 
     44 These exception handlers emulate Unimplemented FP instructions,
     45 instructions using unimplemented data types, and instructions
     46 using unimplemented addressing modes. In addition, this package
     47 includes exception handlers to provide full IEEE-754 compliant
     48 exception handling.
     49 
     50 Release file format:
     51 --------------------
     52 The file fpsp.sa is essentially a hexadecimal image of the
     53 release package. This is the ONLY format which will be supported.
     54 The hex image was created by assembling the source code and
     55 then converting the resulting binary output image into an
     56 ASCII text file. The hexadecimal numbers are listed
     57 using the Motorola Assembly Syntax assembler directive "dc.l"
     58 (define constant longword). The file can be converted to other
     59 assembly syntaxes by using any word processor with a global
     60 search and replace function.
     61 
     62 To assist in assembling and linking this module with other modules,
     63 the installer should add a symbolic label to the top of the file.
     64 This will allow calling routines to access the entry points
     65 of this package.
     66 
     67 The source code fpsp.s has also been included but only for
     68 documentation purposes.
     69 
     70 Release file structure:
     71 -----------------------
     72 
     73 (top of module)
     74 	----------------- 
     75 	|		| - 128 byte-sized section
     76    (1)  |   Call-Out	| - 4 bytes per entry (user fills these in)
     77 	|		| - example routines in fskeleton.s
     78 	-----------------
     79 	|		| - 8 bytes per entry
     80    (2)  | Entry Point	| - user does "bra" or "jmp" to this address
     81 	|		| 
     82 	-----------------
     83 	|		| - code section
     84    (3)  ~		~
     85 	|		|
     86 	-----------------
     87 (bottom of module)
     88 
     89 The first section of this module is the "Call-out" section. This section
     90 is NOT INCLUDED in fpsp.sa (an example "Call-out" section is provided at
     91 the end of the file fskeleton.s). The purpose of this section is to allow 
     92 the FPSP routines to reference external functions that must be provided 
     93 by the host operating system. This section MUST be exactly 128 bytes in 
     94 size. There are 32 fields, each 4 bytes in size. Each field corresponds
     95 to a function required by the FPSP (these functions and their location are
     96 listed in "68060FPSP call-outs" below). Each field entry should contain
     97 the address of the corresponding function RELATIVE to the starting address
     98 of the "call-out" section. The "Call-out" section must sit adjacent to the 
     99 fpsp.sa image in memory.
    100 
    101 The second section, the "Entry-point" section, is used by external routines
    102 to access the functions within the FPSP. Since the fpsp.sa hex file contains
    103 no symbol names, this section contains function entry points that are fixed
    104 with respect to the top of the package. The currently defined entry-points
    105 are listed in section "68060 FPSP entry points" below. A calling routine
    106 would simply execute a "bra" or "jmp" that jumped to the selected function
    107 entry-point.
    108 
    109 For example, if the 68060 hardware took a "Line-F Emulator" exception 
    110 (vector #11), the operating system should execute something similar to:
    111 
    112 	bra	_060FPSP_TOP+128+48
    113 
    114 (_060FPSP_TOP is the starting address of the "Call-out" section; the "Call-out"
    115 section is 128 bytes long; and the F-Line FPSP handler entry point is located
    116 48 bytes from the top of the "Entry-point" section.)
    117 
    118 The third section is the code section. After entering through an "Entry-point",
    119 the entry code jumps to the appropriate emulation code within the code section.
    120 
    121 68060FPSP call-outs: (details in fskeleton.s)
    122 --------------------
    123 0x000:	_060_real_bsun
    124 0x004:	_060_real_snan
    125 0x008:	_060_real_operr
    126 0x00c:	_060_real_ovfl
    127 0x010:	_060_real_unfl
    128 0x014:	_060_real_dz
    129 0x018:	_060_real_inex
    130 0x01c:	_060_real_fline
    131 0x020:	_060_real_fpu_disabled
    132 0x024:	_060_real_trap
    133 0x028:	_060_real_trace
    134 0x02c:	_060_real_access
    135 0x030:	_060_fpsp_done
    136 
    137 0x034:	(Motorola reserved)
    138 0x038:	(Motorola reserved)
    139 0x03c:	(Motorola reserved)
    140 
    141 0x040:	_060_imem_read
    142 0x044:	_060_dmem_read
    143 0x048:	_060_dmem_write
    144 0x04c:	_060_imem_read_word
    145 0x050:	_060_imem_read_long
    146 0x054:	_060_dmem_read_byte
    147 0x058:	_060_dmem_read_word
    148 0x05c:	_060_dmem_read_long
    149 0x060:	_060_dmem_write_byte
    150 0x064:	_060_dmem_write_word
    151 0x068:	_060_dmem_write_long
    152 
    153 0x06c:	(Motorola reserved)
    154 0x070:	(Motorola reserved)
    155 0x074:	(Motorola reserved)
    156 0x078:	(Motorola reserved)
    157 0x07c:	(Motorola reserved)
    158 
    159 68060FPSP entry points:
    160 -----------------------
    161 0x000:	_060_fpsp_snan
    162 0x008:	_060_fpsp_operr
    163 0x010:	_060_fpsp_ovfl
    164 0x018:	_060_fpsp_unfl
    165 0x020:	_060_fpsp_dz
    166 0x028:	_060_fpsp_inex
    167 0x030:	_060_fpsp_fline
    168 0x038:	_060_fpsp_unsupp
    169 0x040:	_060_fpsp_effadd
    170 
    171 
    173 Miscellaneous:
    174 --------------
    175 
    176 _060_fpsp_snan:
    177 ----------------
    178 - documented in 3.5 of 060SP spec.
    179 - Basic flow:
    180 	exception taken ---> enter _060_fpsp_snan --|
    181 						    |
    182             always exits through _060_real_snan <----
    183 
    184 _060_fpsp_operr:
    185 ----------------
    186 - documented in 3.5 of 060SP spec.
    187 - Basic flow:
    188 	exception taken ---> enter _060_fpsp_operr --|
    189 						     |
    190            always exits through _060_real_operr <-----
    191 
    192 _060_fpsp_dz:
    193 ----------------
    194 - documented in 3.7 of 060SP spec.
    195 - Basic flow:
    196 	exception taken ---> enter _060_fpsp_dz   --|
    197 						    |
    198             always exits through _060_real_dz   <----
    199 
    200 _060_fpsp_inex:
    201 ----------------
    202 - documented in 3.6 of 060SP spec.
    203 - Basic flow:
    204 	exception taken ---> enter _060_fpsp_inex --|
    205 						    |
    206             always exits through _060_real_inex <----
    207 
    209 _060_fpsp_ovfl:
    210 ----------------
    211 - documented in 3.4 of 060SP spec.
    212 - Basic flow:
    213 	exception taken ---> enter _060_fpsp_ovfl --|
    214 						    |
    215             may exit through _060_real_inex     <---|
    216 						 or |
    217             may exit through _060_real_ovfl     <---|
    218 						 or |
    219             may exit through _060_fpsp_done     <---|
    220 
    221 _060_fpsp_unfl:
    222 ----------------
    223 - documented in 3.4 of 060SP spec.
    224 - Basic flow:
    225 	exception taken ---> enter _060_fpsp_unfl --|
    226 						    |
    227             may exit through _060_real_inex     <---|
    228 						 or |
    229             may exit through _060_real_unfl     <---|
    230 						 or |
    231             may exit through _060_fpsp_done     <---|
    232 
    234 _060_fpsp_fline:
    235 -----------------
    236 - not fully documented in 060SP spec.
    237 - Basic flow:
    238 	exception taken ---> enter _060_fpsp_fline --|
    239 						     |
    240             -------------------------------------------
    241             |               |                     |
    242             v               v                     v
    243    (unimplemented   (fpu disabled)       (possible F-line illegal)
    244      stack frame)           |                     v
    245             |               v               special case "fmovecr"?
    246             |         exit through                    |
    247             |     _060_real_fpu_disabled        -------------
    248             |                                   |           |
    249             |               ^                   v           v
    250             |               |                 (yes)        (no)
    251             |               |                   v           v
    252             |               |             fpu disabled?   exit through
    253             |               |                   |         _060_real_fline
    254             v               |             -------------
    255             |               |             |           |
    256             |               |             v           v
    257             |               |-----------(yes)        (no)
    258             |                                         |
    259             |----<------------------------------------|
    260             |
    261             |
    262             |----> may exit through _060_real_trace
    263             |
    264             |----> may exit through _060_real_trap
    265             |
    266             |----> may exit through _060_real_bsun
    267             |
    268             |----> may exit through _060_fpsp_done
    269 
    271 _060_fpsp_unsupp:
    272 ------------------
    273 - documented in 3.1 of 060SP spec.
    274 - Basic flow:
    275 	exception taken ---> enter _060_fpsp_unsupp --|
    276 						      |
    277 						      |
    278             may exit through _060_real_snan      <----|
    279 						  or  |
    280             may exit through _060_real_operr     <----|
    281 						  or  |
    282             may exit through _060_real_ovfl      <----|
    283 						  or  |
    284             may exit through _060_real_unfl      <----|
    285 						  or  |
    286             may exit through _060_real_inex      <----|
    287 						  or  |
    288             may exit through _060_real_trace     <----|
    289 						  or  |
    290             may exit through _060_fpsp_done      <----|
    291 
    293 _060_fpsp_effadd:
    294 ------------------
    295 - documented in 3.3 of 060 spec.
    296 - Basic flow:
    297 	exception taken ---> enter _060_fpsp_effadd --|
    298 						      |
    299 						      |
    300             may exit through _060_real_trace     <----|
    301 						  or  |
    302      may exit through _060_real_fpu_disabled     <----|
    303 						  or  |
    304             may exit through _060_fpsp_done      <----|
    305