config/target.in
author "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>
Mon Jul 30 20:02:13 2007 +0000 (2007-07-30)
changeset 305 00a7e6c275da
parent 283 defda3b376bf
child 347 10d6514f4f94
permissions -rw-r--r--
Remove any reference to libfloat. That has gone once and for all.

Rationale:
Most of the time, soft-float problems are caused by this sucker of gcc:
it has support for soft float for all of the targets I've tried so far,
but does not activate this code until you dwelve into half a dozen of
files to make it accept to build and link the support code...

So, yes: gcc has soft-float support. And again, yes: gcc is a sucker.
yann@1
     1
# Target definition: architecture, optimisations, etc...
yann@1
     2
yann@1
     3
menu "Target options"
yann@1
     4
yann@1
     5
comment "General target options"
yann@1
     6
yann@47
     7
config ARCH
yann@47
     8
    string
yann@47
     9
    default "arm"     if ARCH_ARM
yann@47
    10
    default "mips"    if ARCH_MIPS
yann@47
    11
    default "x86"     if ARCH_x86
yann@47
    12
    default "x86_64"  if ARCH_x86_64
yann@47
    13
yann@1
    14
choice
yann@1
    15
    bool
yann@1
    16
    prompt "Target architecture:"
yann@1
    17
    default ARCH_x86
yann@1
    18
yann@1
    19
config ARCH_ARM
yann@1
    20
    bool
yann@1
    21
    prompt "arm"
yann@136
    22
    select ARCH_SUPPORTS_BOTH_ENDIAN
yann@1
    23
yann@1
    24
config ARCH_MIPS
yann@1
    25
    bool
yann@1
    26
    prompt "mips"
yann@136
    27
    select ARCH_SUPPORTS_BOTH_ENDIAN
yann@1
    28
yann@1
    29
config ARCH_x86
yann@1
    30
    bool
yann@1
    31
    prompt "x86"
yann@1
    32
yann@1
    33
config ARCH_x86_64
yann@1
    34
    bool
yann@1
    35
    prompt "x86_64"
yann@1
    36
yann@1
    37
endchoice
yann@1
    38
yann@136
    39
config ARCH_SUPPORTS_BOTH_ENDIAN
yann@35
    40
    bool
yann@35
    41
    default n
yann@35
    42
yann@1
    43
choice
yann@1
    44
    bool
yann@1
    45
    prompt "Endianness:"
yann@136
    46
    depends on ARCH_SUPPORTS_BOTH_ENDIAN
yann@1
    47
yann@1
    48
config ARCH_BE
yann@1
    49
    bool
yann@1
    50
    prompt "Big endian"
yann@1
    51
yann@1
    52
config ARCH_LE
yann@1
    53
    bool
yann@1
    54
    prompt "Little endian"
yann@1
    55
yann@1
    56
endchoice
yann@1
    57
yann@1
    58
comment "Target optimisations"
yann@1
    59
yann@47
    60
config ARCH_ARCH
yann@47
    61
    string
yann@47
    62
    prompt "Achitecture level"
yann@47
    63
    default ""
yann@47
    64
    help
yann@47
    65
      GCC uses this name to determine what kind of instructions it can emit
yann@47
    66
      when generating assembly code. This option can be used in conjunction
yann@47
    67
      with or instead of the ARCH_CPU option (above), or a (command-line)
yann@47
    68
      -mcpu= option.
yann@47
    69
      
yann@47
    70
      This is the configuration flag --with-arch=XXXX, and the runtime flag
yann@47
    71
      -march=XXX.
yann@47
    72
      
yann@47
    73
      Pick a value from the gcc manual for your choosen gcc version and your
yann@47
    74
      target CPU.
yann@47
    75
      
yann@47
    76
      Leave blank if you don't know, or if your target architecture does not
yann@47
    77
      offer this option.
yann@47
    78
yann@45
    79
config ARCH_ABI
yann@45
    80
    string
yann@45
    81
    prompt "Generate code for the specific ABI"
yann@45
    82
    default ""
yann@45
    83
    help
yann@45
    84
      Generate code for the given ABI.
yann@45
    85
yann@47
    86
      This is the configuration flag --with-abi=XXXX, and the runtime flag
yann@47
    87
      -mabi=XXX.
yann@47
    88
yann@45
    89
      Pick a value from the gcc manual for your choosen gcc version and your
yann@45
    90
      target CPU.
yann@45
    91
yann@45
    92
      Leave blank if you don't know, or if your target architecutre does not
yann@45
    93
      offer this option.
yann@45
    94
yann@1
    95
config ARCH_CPU
yann@1
    96
    string
yann@1
    97
    prompt "Emit assembly for CPU"
yann@1
    98
    default ""
yann@1
    99
    help
yann@283
   100
      This specifies the name of the target processor. GCC uses this name
yann@1
   101
      to determine what kind of instructions it can emit when generating
yann@1
   102
      assembly code.
yann@1
   103
      
yann@47
   104
      This is the configuration flag --with-cpu=XXXX, and the runtime flag
yann@47
   105
      -mcpu=XXX.
yann@47
   106
yann@1
   107
      Pick a value from the gcc manual for your choosen gcc version and your
yann@1
   108
      target CPU.
yann@1
   109
      
yann@1
   110
      Leave blank if you don't know, or if your target architecture does not
yann@1
   111
      offer this option.
yann@1
   112
yann@1
   113
config ARCH_TUNE
yann@1
   114
    string
yann@1
   115
    prompt "Tune for CPU"
yann@1
   116
    default ""
yann@1
   117
    help
yann@1
   118
      This option is very similar to the ARCH_CPU option (above), except
yann@1
   119
      that instead of specifying the actual target processor type, and hence
yann@1
   120
      restricting which instructions can be used, it specifies that GCC should
yann@1
   121
      tune the performance of the code as if the target were of the type
yann@1
   122
      specified in this option, but still choosing the instructions that it
yann@1
   123
      will generate based on the cpu specified by the ARCH_CPU option
yann@1
   124
      (above), or a (command-line) -mcpu= option.
yann@1
   125
      
yann@47
   126
      This is the configuration flag --with-tune=XXXX, and the runtime flag
yann@47
   127
      -mtune=XXX.
yann@1
   128
      
yann@1
   129
      Pick a value from the gcc manual for your choosen gcc version and your
yann@1
   130
      target CPU.
yann@1
   131
      
yann@1
   132
      Leave blank if you don't know, or if your target architecture does not
yann@1
   133
      offer this option.
yann@1
   134
yann@1
   135
config ARCH_FPU
yann@1
   136
    string
yann@47
   137
    prompt "Use specific FPU"
yann@1
   138
    default ""
yann@1
   139
    help
yann@1
   140
      On some targets (eg. ARM), you can specify the kind of FPU to emit
yann@1
   141
      code for.
yann@47
   142
yann@47
   143
      This is the configuration flag --with-fpu=XXX, and the runtime flag
yann@47
   144
      -mfpu=XXX.
yann@1
   145
      
yann@1
   146
      See below wether to actually emit FP opcodes, or to emulate them.
yann@1
   147
      
yann@1
   148
      Pick a value from the gcc manual for your choosen gcc version and your
yann@1
   149
      target CPU.
yann@1
   150
      
yann@1
   151
      Leave blank if you don't know, or if your target architecture does not
yann@1
   152
      offer this option.
yann@1
   153
yann@1
   154
choice
yann@1
   155
    bool
yann@1
   156
    prompt "Floating point:"
yann@1
   157
yann@1
   158
config ARCH_FLOAT_HW
yann@1
   159
    bool
yann@1
   160
    prompt "hardware (FPU)"
yann@1
   161
    help
yann@1
   162
      Emit hardware floating point opcodes.
yann@1
   163
      
yann@1
   164
      If you've got a processor with a FPU, then you want that.
yann@1
   165
      If your hardware has no FPU, you still can use HW floating point, but
yann@1
   166
      need to compile support for FPU emulation in your kernel. Needless to
yann@1
   167
      say that emulating the FPU is /slooowwwww/...
yann@1
   168
      
yann@1
   169
      One situation you'd want HW floating point without a FPU is if you get
yann@1
   170
      binary blobs from different vendors that are compiling this way and
yann@1
   171
      can't (don't wan't to) change.
yann@1
   172
yann@1
   173
config ARCH_FLOAT_SW
yann@1
   174
    bool
yann@1
   175
    prompt "software"
yann@1
   176
    help
yann@1
   177
      Do not emit any hardware floating point opcode.
yann@1
   178
      
yann@1
   179
      If your processor has no FPU, then you most probably want this, as it
yann@1
   180
      is faster than emulating the FPU in the kernel.
yann@1
   181
yann@1
   182
endchoice
yann@1
   183
yann@1
   184
config TARGET_CFLAGS
yann@1
   185
    string
yann@41
   186
    prompt "Target CFLAGS"
yann@1
   187
    default ""
yann@1
   188
    help
yann@1
   189
      Used to add specific options when compiling libraries of the toolchain,
yann@1
   190
      that will run on the target (eg. libc.so).
yann@1
   191
      
yann@1
   192
      Note that the options above for CPU, tune, arch and FPU will be
yann@1
   193
      automaticaly used. You don't need to specify them here.
yann@1
   194
      
yann@1
   195
      Leave blank if you don't know better.
yann@1
   196
yann@1
   197
endmenu