gdb/sparc-ravenscar-thread.c

   1 /* Ravenscar SPARC target support.
   2
   3    Copyright (C) 2004-2020 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 #include "gdbarch.h"
  28
  29 struct sparc_ravenscar_ops : public ravenscar_arch_ops
  30 {
  31   void fetch_registers (struct regcache *, int) override;
  32   void store_registers (struct regcache *, int) override;
  33 };
  34
  35 /* Register offsets from a referenced address (exempli gratia the
  36    Thread_Descriptor).  The referenced address depends on the register
  37    number.  The Thread_Descriptor layout and the stack layout are documented
  38    in the GNAT sources, in sparc-bb.h.  */
  39
  40 static const int sparc_register_offsets[] =
  41 {
  42   /* G0 - G7 */
  43   -1,   0x24, 0x28, 0x2C, 0x30, 0x34, 0x38, 0x3C,
  44   /* O0 - O7 */
  45   0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18, 0x1C,
  46   /* L0 - L7 */
  47   0x00, 0x04, 0x08, 0x0C, 0x10, 0x14, 0x18, 0x1C,
  48   /* I0 - I7 */
  49   0x20, 0x24, 0x28, 0x2C, 0x30, 0x34, 0x38, 0x3C,
  50   /* F0 - F31 */
  51   0x50, 0x54, 0x58, 0x5C, 0x60, 0x64, 0x68, 0x6C,
  52   0x70, 0x74, 0x78, 0x7C, 0x80, 0x84, 0x88, 0x8C,
  53   0x90, 0x94, 0x99, 0x9C, 0xA0, 0xA4, 0xA8, 0xAC,
  54   0xB0, 0xB4, 0xBB, 0xBC, 0xC0, 0xC4, 0xC8, 0xCC,
  55   /* Y  PSR   WIM   TBR   PC    NPC   FPSR  CPSR */
  56   0x40, 0x20, 0x44, -1,   0x1C, -1,   0x4C, -1
  57 };
  58
  59 /* supply register REGNUM, which has been saved on REGISTER_ADDR, to the
  60    regcache.  */
  61
  62 static void
  63 supply_register_at_address (struct regcache *regcache, int regnum,
  64                             CORE_ADDR register_addr)
  65 {
  66   struct gdbarch *gdbarch = regcache->arch ();
  67   int buf_size = register_size (gdbarch, regnum);
  68   gdb_byte *buf;
  69
  70   buf = (gdb_byte *) alloca (buf_size);
  71   read_memory (register_addr, buf, buf_size);
  72   regcache->raw_supply (regnum, buf);
  73 }
  74
  75 /* Return true if, for a non-running thread, REGNUM has been saved on the
  76    stack.  */
  77
  78 static int
  79 register_on_stack_p (int regnum)
  80 {
  81   return (regnum >= SPARC_L0_REGNUM && regnum <= SPARC_L7_REGNUM)
  82     || (regnum >= SPARC_I0_REGNUM && regnum <= SPARC_I7_REGNUM);
  83 }
  84
  85 /* Return true if, for a non-running thread, REGNUM has been saved on the
  86    Thread_Descriptor.  */
  87
  88 static int
  89 register_in_thread_descriptor_p (int regnum)
  90 {
  91   return (regnum >= SPARC_O0_REGNUM && regnum <= SPARC_O7_REGNUM)
  92     || (regnum == SPARC32_PSR_REGNUM)
  93     || (regnum >= SPARC_G1_REGNUM && regnum <= SPARC_G7_REGNUM)
  94     || (regnum == SPARC32_Y_REGNUM)
  95     || (regnum == SPARC32_WIM_REGNUM)
  96     || (regnum == SPARC32_FSR_REGNUM)
  97     || (regnum >= SPARC_F0_REGNUM && regnum <= SPARC_F0_REGNUM + 31)
  98     || (regnum == SPARC32_PC_REGNUM);
  99 }
 100
 101 /* to_fetch_registers when inferior_ptid is different from the running
 102    thread.  */
 103
 104 void
 105 sparc_ravenscar_ops::fetch_registers (struct regcache *regcache, int regnum)
 106 {
 107   struct gdbarch *gdbarch = regcache->arch ();
 108   const int sp_regnum = gdbarch_sp_regnum (gdbarch);
 109   const int num_regs = gdbarch_num_regs (gdbarch);
 110   int current_regnum;
 111   CORE_ADDR current_address;
 112   CORE_ADDR thread_descriptor_address;
 113   ULONGEST stack_address;
 114
 115   /* The tid is the thread_id field, which is a pointer to the thread.  */
 116   thread_descriptor_address = (CORE_ADDR) inferior_ptid.tid ();
 117
 118   /* Read the saved SP in the context buffer.  */
 119   current_address = thread_descriptor_address
 120     + sparc_register_offsets [sp_regnum];
 121   supply_register_at_address (regcache, sp_regnum, current_address);
 122   regcache_cooked_read_unsigned (regcache, sp_regnum, &stack_address);
 123
 124   /* Read registers.  */
 125   for (current_regnum = 0; current_regnum < num_regs; current_regnum ++)
 126     {
 127       if (register_in_thread_descriptor_p (current_regnum))
 128         {
 129           current_address = thread_descriptor_address
 130             + sparc_register_offsets [current_regnum];
 131           supply_register_at_address (regcache, current_regnum,
 132                                       current_address);
 133         }
 134       else if (register_on_stack_p (current_regnum))
 135         {
 136           current_address = stack_address
 137             + sparc_register_offsets [current_regnum];
 138           supply_register_at_address (regcache, current_regnum,
 139                                       current_address);
 140         }
 141     }
 142 }
 143
 144 /* to_store_registers when inferior_ptid is different from the running
 145    thread.  */
 146
 147 void
 148 sparc_ravenscar_ops::store_registers (struct regcache *regcache, int regnum)
 149 {
 150   struct gdbarch *gdbarch = regcache->arch ();
 151   int buf_size = register_size (gdbarch, regnum);
 152   gdb_byte buf[buf_size];
 153   ULONGEST register_address;
 154
 155   if (register_in_thread_descriptor_p (regnum))
 156     register_address =
 157       inferior_ptid.tid () + sparc_register_offsets [regnum];
 158   else if (register_on_stack_p (regnum))
 159     {
 160       regcache_cooked_read_unsigned (regcache, SPARC_SP_REGNUM,
 161                                      &register_address);
 162       register_address += sparc_register_offsets [regnum];
 163     }
 164   else
 165     return;
 166
 167   regcache->raw_collect (regnum, buf);
 168   write_memory (register_address,
 169                 buf,
 170                 buf_size);
 171 }
 172
 173 static struct sparc_ravenscar_ops sparc_ravenscar_ops;
 174
 175 /* Register ravenscar_arch_ops in GDBARCH.  */
 176
 177 void
 178 register_sparc_ravenscar_ops (struct gdbarch *gdbarch)
 179 {
 180   set_gdbarch_ravenscar_ops (gdbarch, &sparc_ravenscar_ops);
 181 }