gdb/sparc-ravenscar-thread.c

   1 /* Ravenscar SPARC target support.
   2
   3    Copyright (C) 2004-2014 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "gdbcore.h"
  22 #include "regcache.h"
  23 #include "sparc-tdep.h"
  24 #include "inferior.h"
  25 #include "ravenscar-thread.h"
  26 #include "sparc-ravenscar-thread.h"
  27
  28 static void sparc_ravenscar_fetch_registers (struct regcache *regcache,
  29                                              int regnum);
  30 static void sparc_ravenscar_store_registers (struct regcache *regcache,
  31                                              int regnum);
  32 static void sparc_ravenscar_prepare_to_store (struct regcache *regcache);
  33
  34 /* Register offsets from a referenced address (exempli gratia the
  35    Thread_Descriptor).  The referenced address depends on the register
  36    number.  The Thread_Descriptor layout and the stack layout are documented
  37    in the GNAT sources, in sparc-bb.h.  */
  38
  39 static const int sparc_register_offsets[] =
  40 {
  41   /* G0 - G7 */
  42   -1,   0x24, 0x28, 0x2C, 0x30, 0x34, 0x38, 0x3C,
  43   /* O0 - O7 */
  44   0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18, 0x1C,
  45   /* L0 - L7 */
  46   0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18, 0x1C,
  47   /* I0 - I7 */
  48   0x20, 0x24, 0x28, 0x2C, 0x30, 0x34, 0x38, 0x3C,
  49   /* F0 - F31 */
  50   0x50, 0x54, 0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C,
  51   0x70, 0x74, 0x78, 0x7C, 0x80, 0x84, 0x88, 0x8C,
  52   0x90, 0x94, 0x99, 0x9C, 0xA0, 0xA4, 0xA8, 0xAC,
  53   0xB0, 0xB4, 0xBB, 0xBC, 0xC0, 0xC4, 0xC8, 0xCC,
  54   /* Y  PSR   WIM   TBR   PC    NPC   FPSR  CPSR */
  55   0x40, 0x20, 0x44, -1,   0x1C, -1,   0x4C, -1
  56 };
  57
  58 /* supply register REGNUM, which has been saved on REGISTER_ADDR, to the
  59    regcache.  */
  60
  61 static void
  62 supply_register_at_address (struct regcache *regcache, int regnum,
  63                             CORE_ADDR register_addr)
  64 {
  65   struct gdbarch *gdbarch = get_regcache_arch (regcache);
  66   int buf_size = register_size (gdbarch, regnum);
  67   gdb_byte *buf;
  68
  69   buf = alloca (buf_size);
  70   read_memory (register_addr, buf, buf_size);
  71   regcache_raw_supply (regcache, regnum, buf);
  72 }
  73
  74 /* Return true if, for a non-running thread, REGNUM has been saved on the
  75    stack.  */
  76
  77 static int
  78 register_on_stack_p (int regnum)
  79 {
  80   return (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_L7_REGNUM)
  81     || (regnum >= SPARC_I0_REGNUM && regnum <= SPARC_I7_REGNUM);
  82 }
  83
  84 /* Return true if, for a non-running thread, REGNUM has been saved on the
  85    Thread_Descriptor.  */
  86
  87 static int
  88 register_in_thread_descriptor_p (int regnum)
  89 {
  90   return (regnum >= SPARC_O0_REGNUM && regnum <= SPARC_O7_REGNUM)
  91     || (regnum == SPARC32_PSR_REGNUM)
  92     || (regnum >= SPARC_G1_REGNUM && regnum <= SPARC_G7_REGNUM)
  93     || (regnum == SPARC32_Y_REGNUM)
  94     || (regnum == SPARC32_WIM_REGNUM)
  95     || (regnum == SPARC32_FSR_REGNUM)
  96     || (regnum >= SPARC_F0_REGNUM && regnum <= SPARC_F0_REGNUM + 31)
  97     || (regnum == SPARC32_PC_REGNUM);
  98 }
  99
 100 /* to_fetch_registers when inferior_ptid is different from the running
 101    thread.  */
 102
 103 static void
 104 sparc_ravenscar_fetch_registers (struct regcache *regcache, int regnum)
 105 {
 106   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 107   const int sp_regnum = gdbarch_sp_regnum (gdbarch);
 108   const int num_regs = gdbarch_num_regs (gdbarch);
 109   int current_regnum;
 110   CORE_ADDR current_address;
 111   CORE_ADDR thread_descriptor_address;
 112   ULONGEST stack_address;
 113
 114   /* The tid is the thread_id field, which is a pointer to the thread.  */
 115   thread_descriptor_address = (CORE_ADDR) ptid_get_tid (inferior_ptid);
 116
 117   /* Read the saved SP in the context buffer.  */
 118   current_address = thread_descriptor_address
 119     + sparc_register_offsets [sp_regnum];
 120   supply_register_at_address (regcache, sp_regnum, current_address);
 121   regcache_cooked_read_unsigned (regcache, sp_regnum, &stack_address);
 122
 123   /* Read registers.  */
 124   for (current_regnum = 0; current_regnum < num_regs; current_regnum ++)
 125     {
 126       if (register_in_thread_descriptor_p (current_regnum))
 127         {
 128           current_address = thread_descriptor_address
 129             + sparc_register_offsets [current_regnum];
 130           supply_register_at_address (regcache, current_regnum,
 131                                       current_address);
 132         }
 133       else if (register_on_stack_p (current_regnum))
 134         {
 135           current_address = stack_address
 136             + sparc_register_offsets [current_regnum];
 137           supply_register_at_address (regcache, current_regnum,
 138                                       current_address);
 139         }
 140     }
 141 }
 142
 143 /* to_prepare_to_store when inferior_ptid is different from the running
 144    thread.  */
 145
 146 static void
 147 sparc_ravenscar_prepare_to_store (struct regcache *regcache)
 148 {
 149   /* Nothing to do.  */
 150 }
 151
 152 /* to_store_registers when inferior_ptid is different from the running
 153    thread.  */
 154
 155 static void
 156 sparc_ravenscar_store_registers (struct regcache *regcache, int regnum)
 157 {
 158   struct gdbarch *gdbarch = get_regcache_arch (regcache);
 159   int buf_size = register_size (gdbarch, regnum);
 160   gdb_byte buf[buf_size];
 161   ULONGEST register_address;
 162
 163   if (register_in_thread_descriptor_p (regnum))
 164     register_address =
 165       ptid_get_tid (inferior_ptid) + sparc_register_offsets [regnum];
 166   else if (register_on_stack_p (regnum))
 167     {
 168       regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM,
 169                                      &register_address);
 170       register_address += sparc_register_offsets [regnum];
 171     }
 172   else
 173     return;
 174
 175   regcache_raw_collect (regcache, regnum, buf);
 176   write_memory (register_address,
 177                 buf,
 178                 buf_size);
 179 }
 180
 181 static struct ravenscar_arch_ops sparc_ravenscar_ops =
 182 {
 183   sparc_ravenscar_fetch_registers,
 184   sparc_ravenscar_store_registers,
 185   sparc_ravenscar_prepare_to_store
 186 };
 187
 188 /* Register ravenscar_arch_ops in GDBARCH.  */
 189
 190 void
 191 register_sparc_ravenscar_ops (struct gdbarch *gdbarch)
 192 {
 193   set_gdbarch_ravenscar_ops (gdbarch, &sparc_ravenscar_ops);
 194 }