move platform-independent stuff out of /gp2x.
[gpsp.git] / gp2x / arm_stub.S
diff --git a/gp2x/arm_stub.S b/gp2x/arm_stub.S
deleted file mode 100644 (file)
index a7271fd..0000000
+++ /dev/null
@@ -1,1004 +0,0 @@
-.align 2
-
-.global arm_update_gba_arm
-.global arm_update_gba_thumb
-.global arm_update_gba_idle_arm
-.global arm_update_gba_idle_thumb
-
-.global arm_indirect_branch_arm
-.global arm_indirect_branch_thumb
-.global arm_indirect_branch_dual_arm
-.global arm_indirect_branch_dual_thumb
-
-.global execute_arm_translate
-
-.global execute_store_u8
-.global execute_store_u16
-.global execute_store_u32
-.global execute_store_u32_safe
-
-.global execute_load_u8
-.global execute_load_s8
-.global execute_load_u16
-.global execute_load_s16
-.global execute_load_u32
-
-.global execute_store_cpsr
-.global execute_read_spsr
-.global execute_store_spsr
-.global execute_spsr_restore
-
-.global execute_swi_arm
-.global execute_swi_thumb
-
-.global execute_patch_bios_read
-.global execute_patch_bios_protect
-
-.global execute_bios_ptr_protected
-.global execute_bios_rom_ptr
-
-
-.global step_debug_arm
-
-.global invalidate_icache_region
-.global invalidate_cache_region
-
-.global memory_map_read
-.global memory_map_write
-.global reg
-
-#define REG_BASE_OFFSET   1024
-
-#define REG_R0            (REG_BASE_OFFSET + (0 * 4))
-#define REG_R1            (REG_BASE_OFFSET + (1 * 4))
-#define REG_R2            (REG_BASE_OFFSET + (2 * 4))
-#define REG_R3            (REG_BASE_OFFSET + (3 * 4))
-#define REG_R4            (REG_BASE_OFFSET + (4 * 4))
-#define REG_R5            (REG_BASE_OFFSET + (5 * 4))
-#define REG_R6            (REG_BASE_OFFSET + (6 * 4))
-#define REG_R7            (REG_BASE_OFFSET + (7 * 4))
-#define REG_R8            (REG_BASE_OFFSET + (8 * 4))
-#define REG_R9            (REG_BASE_OFFSET + (9 * 4))
-#define REG_R10           (REG_BASE_OFFSET + (10 * 4))
-#define REG_R11           (REG_BASE_OFFSET + (11 * 4))
-#define REG_R12           (REG_BASE_OFFSET + (12 * 4))
-#define REG_R13           (REG_BASE_OFFSET + (13 * 4))
-#define REG_R14           (REG_BASE_OFFSET + (14 * 4))
-#define REG_SP            (REG_BASE_OFFSET + (13 * 4))
-#define REG_LR            (REG_BASE_OFFSET + (14 * 4))
-#define REG_PC            (REG_BASE_OFFSET + (15 * 4))
-
-#define REG_N_FLAG        (REG_BASE_OFFSET + (16 * 4))
-#define REG_Z_FLAG        (REG_BASE_OFFSET + (17 * 4))
-#define REG_C_FLAG        (REG_BASE_OFFSET + (18 * 4))
-#define REG_V_FLAG        (REG_BASE_OFFSET + (19 * 4))
-#define REG_CPSR          (REG_BASE_OFFSET + (20 * 4))
-
-#define REG_SAVE          (REG_BASE_OFFSET + (21 * 4))
-#define REG_SAVE2         (REG_BASE_OFFSET + (22 * 4))
-#define REG_SAVE3         (REG_BASE_OFFSET + (23 * 4))
-
-#define CPU_MODE          (REG_BASE_OFFSET + (29 * 4))
-#define CPU_HALT_STATE    (REG_BASE_OFFSET + (30 * 4))
-#define CHANGED_PC_STATUS (REG_BASE_OFFSET + (31 * 4))
-
-
-#define reg_a0            r0
-#define reg_a1            r1
-#define reg_a2            r2
-
-#define reg_s0            r9
-#define reg_base          sp
-#define reg_flags         r11
-
-#define reg_cycles        r12
-
-#define reg_x0            r3
-#define reg_x1            r4
-#define reg_x2            r5
-#define reg_x3            r6
-#define reg_x4            r7
-#define reg_x5            r8
-
-
-#define MODE_SUPERVISOR   3
-
-
-@ Will load the register set from memory into the appropriate cached registers.
-@ See arm_emit.h for listing explanation.
-
-#define load_registers_arm()                                                 ;\
-  ldr reg_x0, [reg_base, #REG_R0]                                            ;\
-  ldr reg_x1, [reg_base, #REG_R1]                                            ;\
-  ldr reg_x2, [reg_base, #REG_R6]                                            ;\
-  ldr reg_x3, [reg_base, #REG_R9]                                            ;\
-  ldr reg_x4, [reg_base, #REG_R12]                                           ;\
-  ldr reg_x5, [reg_base, #REG_R14]                                           ;\
-
-#define load_registers_thumb()                                               ;\
-  ldr reg_x0, [reg_base, #REG_R0]                                            ;\
-  ldr reg_x1, [reg_base, #REG_R1]                                            ;\
-  ldr reg_x2, [reg_base, #REG_R2]                                            ;\
-  ldr reg_x3, [reg_base, #REG_R3]                                            ;\
-  ldr reg_x4, [reg_base, #REG_R4]                                            ;\
-  ldr reg_x5, [reg_base, #REG_R5]                                            ;\
-
-
-@ Will store the register set from cached registers back to memory.
-
-#define store_registers_arm()                                                ;\
-  str reg_x0, [reg_base, #REG_R0]                                            ;\
-  str reg_x1, [reg_base, #REG_R1]                                            ;\
-  str reg_x2, [reg_base, #REG_R6]                                            ;\
-  str reg_x3, [reg_base, #REG_R9]                                            ;\
-  str reg_x4, [reg_base, #REG_R12]                                           ;\
-  str reg_x5, [reg_base, #REG_R14]                                           ;\
-
-#define store_registers_thumb()                                              ;\
-  str reg_x0, [reg_base, #REG_R0]                                            ;\
-  str reg_x1, [reg_base, #REG_R1]                                            ;\
-  str reg_x2, [reg_base, #REG_R2]                                            ;\
-  str reg_x3, [reg_base, #REG_R3]                                            ;\
-  str reg_x4, [reg_base, #REG_R4]                                            ;\
-  str reg_x5, [reg_base, #REG_R5]                                            ;\
-
-
-@ Returns an updated persistent cpsr with the cached flags register.
-@ Uses reg as a temporary register and returns the CPSR here.
-
-#define collapse_flags_no_update(reg)                                        ;\
-  ldr reg, [reg_base, #REG_CPSR]          /* reg = cpsr                    */;\
-  bic reg, reg, #0xF0000000               /* clear ALU flags in cpsr       */;\
-  and reg_flags, reg_flags, #0xF0000000   /* clear non-ALU flags           */;\
-  orr reg, reg, reg_flags                 /* update cpsr with ALU flags    */;\
-
-@ Updates cpsr using the above macro.
-
-#define collapse_flags(reg)                                                  ;\
-  collapse_flags_no_update(reg)                                              ;\
-  str reg, [reg_base, #REG_CPSR]                                             ;\
-
-@ Loads the saved flags register from the persistent cpsr.
-
-#define extract_flags()                                                      ;\
-  ldr reg_flags, [reg_base, #REG_CPSR]                                       ;\
-  msr cpsr_f, reg_flags                                                      ;\
-
-
-#define save_flags()                                                         ;\
-  mrs reg_flags, cpsr                                                        ;\
-
-#define restore_flags()                                                      ;\
-  msr cpsr_f, reg_flags                                                      ;\
-
-@ Calls a C function - all caller save registers which are important to the
-@ dynarec and to returning from this function are saved.
-
-#define call_c_function(function)                                            ;\
-  stmdb sp!, { r3, r12, lr }                                                 ;\
-  bl function                                                                ;\
-  ldmia sp!, { r3, r12, lr }                                                 ;\
-
-
-@ Update the GBA hardware (video, sound, input, etc)
-
-@ Input:
-@ r0: current PC
-
-#define return_straight()                                                    ;\
-  bx lr                                                                      ;\
-
-#define return_add()                                                         ;\
-  add pc, lr, #4                                                             ;\
-
-#define load_pc_straight()                                                   ;\
-  ldr r0, [lr, #-8]                                                          ;\
-
-#define load_pc_add()                                                        ;\
-  ldr r0, [lr]                                                               ;\
-
-
-#define arm_update_gba_builder(name, mode, return_op)                        ;\
-                                                                             ;\
-arm_update_gba_##name:                                                       ;\
-  load_pc_##return_op()                                                      ;\
-  str r0, [reg_base, #REG_PC]             /* write out the PC              */;\
-                                                                             ;\
-  save_flags()                                                               ;\
-  collapse_flags(r0)                      /* update the flags              */;\
-                                                                             ;\
-  store_registers_##mode()                /* save out registers            */;\
-  call_c_function(update_gba)             /* update GBA state              */;\
-                                                                             ;\
-  mvn reg_cycles, r0                      /* load new cycle count          */;\
-                                                                             ;\
-  ldr r0, [reg_base, #CHANGED_PC_STATUS]  /* load PC changed status        */;\
-  cmp r0, #0                              /* see if PC has changed         */;\
-  beq 1f                                  /* if not return                 */;\
-                                                                             ;\
-  ldr r0, [reg_base, #REG_PC]             /* load new PC                   */;\
-  ldr r1, [reg_base, #REG_CPSR]           /* r1 = flags                    */;\
-  tst r1, #0x20                           /* see if Thumb bit is set       */;\
-  bne 2f                                  /* if so load Thumb PC           */;\
-                                                                             ;\
-  load_registers_arm()                    /* load ARM regs                 */;\
-  call_c_function(block_lookup_address_arm)                                  ;\
-  restore_flags()                                                            ;\
-  bx r0                                   /* jump to new ARM block         */;\
-                                                                             ;\
-1:                                                                           ;\
-  load_registers_##mode()                 /* reload registers              */;\
-  restore_flags()                                                            ;\
-  return_##return_op()                                                       ;\
-                                                                             ;\
-2:                                                                           ;\
-  load_registers_thumb()                  /* load Thumb regs               */;\
-  call_c_function(block_lookup_address_thumb)                                ;\
-  restore_flags()                                                            ;\
-  bx r0                                   /* jump to new ARM block         */;\
-
-
-arm_update_gba_builder(arm, arm, straight)
-arm_update_gba_builder(thumb, thumb, straight)
-
-arm_update_gba_builder(idle_arm, arm, add)
-arm_update_gba_builder(idle_thumb, thumb, add)
-
-
-
-@ These are b stubs for performing indirect branches. They are not
-@ linked to and don't return, instead they link elsewhere.
-
-@ Input:
-@ r0: PC to branch to
-
-arm_indirect_branch_arm:
-  save_flags()
-  call_c_function(block_lookup_address_arm)
-  restore_flags()
-  bx r0
-
-arm_indirect_branch_thumb:
-  save_flags()
-  call_c_function(block_lookup_address_thumb)
-  restore_flags()
-  bx r0
-
-arm_indirect_branch_dual_arm:
-  save_flags()
-  tst r0, #0x01                           @ check lower bit
-  bne 1f                                  @ if set going to Thumb mode
-  call_c_function(block_lookup_address_arm)
-  restore_flags()
-  bx r0                                   @ return
-
-1:
-  bic r0, r0, #0x01
-  store_registers_arm()                   @ save out ARM registers
-  load_registers_thumb()                  @ load in Thumb registers
-  ldr r1, [reg_base, #REG_CPSR]           @ load cpsr
-  orr r1, r1, #0x20                       @ set Thumb mode
-  str r1, [reg_base, #REG_CPSR]           @ store flags
-  call_c_function(block_lookup_address_thumb)
-  restore_flags()
-  bx r0                                   @ return
-
-arm_indirect_branch_dual_thumb:
-  save_flags()
-  tst r0, #0x01                           @ check lower bit
-  beq 1f                                  @ if set going to ARM mode
-  bic r0, r0, #0x01
-  call_c_function(block_lookup_address_thumb)
-  restore_flags()
-  bx r0                                   @ return
-
-1:
-  store_registers_thumb()                 @ save out Thumb registers
-  load_registers_arm()                    @ load in ARM registers
-  ldr r1, [reg_base, #REG_CPSR]           @ load cpsr
-  bic r1, r1, #0x20                       @ clear Thumb mode
-  str r1, [reg_base, #REG_CPSR]           @ store flags
-  call_c_function(block_lookup_address_arm)
-  restore_flags()
-  bx r0                                   @ return
-
-
-@ Update the cpsr.
-
-@ Input:
-@ r0: new cpsr value
-@ r1: bitmask of which bits in cpsr to update
-@ r2: current PC
-
-execute_store_cpsr:
-  save_flags()
-  and reg_flags, r0, r1                   @ reg_flags = new_cpsr & store_mask
-  ldr r0, [reg_base, #REG_CPSR]           @ r0 = cpsr
-  bic r0, r0, r1                          @ r0 = cpsr & ~store_mask
-  orr reg_flags, reg_flags, r0            @ reg_flags = new_cpsr | cpsr
-
-  mov r0, reg_flags                       @ also put new cpsr in r0
-
-  store_registers_arm()                   @ save ARM registers
-  ldr r2, [lr]                            @ r2 = pc
-  call_c_function(execute_store_cpsr_body)
-  load_registers_arm()                    @ restore ARM registers
-
-  cmp r0, #0                              @ check new PC
-  beq 1f                                  @ if it's zero, return
-
-  call_c_function(block_lookup_address_arm)
-
-  restore_flags()
-  bx r0                                   @ return to new ARM address
-
-1:
-  restore_flags()
-  add pc, lr, #4                          @ return
-
-
-@ Update the current spsr.
-
-@ Input:
-@ r0: new cpsr value
-@ r1: bitmask of which bits in spsr to update
-
-execute_store_spsr:
-  ldr r1, 1f                              @ r1 = spsr
-  ldr r2, [reg_base, #CPU_MODE]           @ r2 = CPU_MODE
-  str r0, [r1, r2, lsl #2]                @ spsr[CPU_MODE] = new_spsr
-  bx lr
-
-1:
-  .word spsr
-
-@ Read the current spsr.
-
-@ Output:
-@ r0: spsr
-
-execute_read_spsr:
-  ldr r0, 1b                              @ r0 = spsr
-  ldr r1, [reg_base, #CPU_MODE]           @ r1 = CPU_MODE
-  ldr r0, [r0, r1, lsl #2]                @ r0 = spsr[CPU_MODE]
-  bx lr                                   @ return
-
-
-@ Restore the cpsr from the mode spsr and mode shift.
-
-@ Input:
-@ r0: current pc
-
-execute_spsr_restore:
-  save_flags()
-  ldr r1, 1f                              @ r1 = spsr
-  ldr r2, [reg_base, #CPU_MODE]           @ r2 = cpu_mode
-  ldr r1, [r1, r2, lsl #2]                @ r1 = spsr[cpu_mode] (new cpsr)
-  str r1, [reg_base, #REG_CPSR]           @ update cpsr
-  mov reg_flags, r1                       @ also, update shadow flags
-
-  @ This function call will pass r0 (address) and return it.
-  store_registers_arm()                   @ save ARM registers
-  call_c_function(execute_spsr_restore_body)
-
-  ldr r1, [reg_base, #REG_CPSR]           @ r1 = cpsr
-  tst r1, #0x20                           @ see if Thumb mode is set
-  bne 2f                                  @ if so handle it
-
-  load_registers_arm()                    @ restore ARM registers
-  call_c_function(block_lookup_address_arm)
-  restore_flags()
-  bx r0
-
-  @ This will service execute_spsr_restore and execute_swi
-1:
-  .word spsr
-
-2:
-  load_registers_thumb()                  @ load Thumb registers
-  call_c_function(block_lookup_address_thumb)
-  restore_flags()
-  bx r0
-
-
-
-@ Setup the mode transition work for calling an SWI.
-
-@ Input:
-@ r0: current pc
-
-#define execute_swi_builder(mode)                                            ;\
-                                                                             ;\
-execute_swi_##mode:                                                          ;\
-  save_flags()                                                               ;\
-  ldr r1, 1f                              /* r1 = reg_mode                 */;\
-  /* reg_mode[MODE_SUPERVISOR][6] = pc                                     */;\
-  ldr r0, [lr]                            /* load PC                       */;\
-  str r0, [r1, #((MODE_SUPERVISOR * (7 * 4)) + (6 * 4))]                     ;\
-  collapse_flags_no_update(r0)            /* r0 = cpsr                     */;\
-  ldr r1, 2f                              /* r1 = spsr                     */;\
-  str r0, [r1, #(MODE_SUPERVISOR * 4)]    /* spsr[MODE_SUPERVISOR] = cpsr  */;\
-  bic r0, r0, #0x3F                       /* clear mode flag in r0         */;\
-  orr r0, r0, #0x13                       /* set to supervisor mode        */;\
-  str r0, [reg_base, #REG_CPSR]           /* update cpsr                   */;\
-                                                                             ;\
-  call_c_function(bios_region_read_allow)                                    ;\
-                                                                             ;\
-  mov r0, #MODE_SUPERVISOR                                                   ;\
-                                                                             ;\
-  store_registers_##mode()                /* store regs for mode           */;\
-  call_c_function(set_cpu_mode)           /* set the CPU mode to svsr      */;\
-  load_registers_arm()                    /* load ARM regs                 */;\
-                                                                             ;\
-  restore_flags()                                                            ;\
-  add pc, lr, #4                          /* return                        */;\
-                                                                             ;\
-1:                                                                           ;\
-  .word reg_mode                                                             ;\
-                                                                             ;\
-2:                                                                           ;\
-  .word spsr                                                                 ;\
-                                                                             ;\
-3:                                                                           ;\
-  .word execute_bios_rom_ptr                                                 ;\
-
-execute_swi_builder(arm)
-execute_swi_builder(thumb)
-
-
-@ Wrapper for calling SWI functions in C (or can implement some in ASM if
-@ desired)
-
-#define execute_swi_function_builder(swi_function, mode)                     ;\
-                                                                             ;\
-  .global execute_swi_hle_##swi_function##_##mode                            ;\
-execute_swi_hle_##swi_function##_##mode:                                     ;\
-  save_flags()                                                               ;\
-  store_registers_##mode()                                                   ;\
-  call_c_function(execute_swi_hle_##swi_function##_c)                        ;\
-  load_registers_##mode()                                                    ;\
-  restore_flags()                                                            ;\
-  bx lr                                                                      ;\
-
-execute_swi_function_builder(div, arm)
-execute_swi_function_builder(div, thumb)
-
-
-@ Start program execution. Normally the mode should be Thumb and the
-@ PC should be 0x8000000, however if a save state is preloaded this
-@ will be different.
-
-@ Input:
-@ r0: initial value for cycle counter
-
-@ Uses sp as reg_base; must hold consistently true.
-
-execute_arm_translate:
-  sub sp, sp, #0x100                      @ allocate room for register data
-
-  mvn reg_cycles, r0                      @ load cycle counter
-
-  mov r0, reg_base                        @ load reg_base into first param
-  call_c_function(move_reg)               @ make reg_base the new reg ptr
-
-  sub sp, sp, #REG_BASE_OFFSET            @ allocate room for ptr table
-  bl load_ptr_read_function_table         @ load read function ptr table
-
-  ldr r0, [reg_base, #REG_PC]             @ r0 = current pc
-  ldr r1, [reg_base, #REG_CPSR]           @ r1 = flags
-  tst r1, #0x20                           @ see if Thumb bit is set
-
-  bne 1f                                  @ if so lookup thumb
-
-  load_registers_arm()                    @ load ARM registers
-  call_c_function(block_lookup_address_arm)
-  extract_flags()                         @ load flags
-  bx r0                                   @ jump to first ARM block
-
-1:
-  load_registers_thumb()                  @ load Thumb registers
-  call_c_function(block_lookup_address_thumb)
-  extract_flags()                         @ load flags
-  bx r0                                   @ jump to first Thumb block
-
-
-@ Write out to memory.
-
-@ Input:
-@ r0: address
-@ r1: value
-@ r2: current pc
-
-#define execute_store_body(store_type, store_op)                             ;\
-  save_flags()                                                               ;\
-  stmdb sp!, { lr }                       /* save lr                       */;\
-  tst r0, #0xF0000000                     /* make sure address is in range */;\
-  bne ext_store_u##store_type             /* if not do ext store           */;\
-                                                                             ;\
-  ldr r2, 1f                              /* r2 = memory_map_write         */;\
-  mov lr, r0, lsr #15                     /* lr = page index of address    */;\
-  ldr r2, [r2, lr, lsl #2]                /* r2 = memory page              */;\
-                                                                             ;\
-  cmp r2, #0                              /* see if map is ext             */;\
-  beq ext_store_u##store_type             /* if so do ext store            */;\
-                                                                             ;\
-  mov r0, r0, lsl #17                     /* isolate bottom 15 bits in top */;\
-  mov r0, r0, lsr #17                     /* like performing and 0x7FFF    */;\
-  store_op r1, [r2, r0]                   /* store result                  */;\
-
-
-#define store_align_8()                                                      ;\
-
-#define store_align_16()                                                     ;\
-  bic r0, r0, #0x01                                                          ;\
-
-#define store_align_32()                                                     ;\
-  bic r0, r0, #0x03                                                          ;\
-
-
-#define execute_store_builder(store_type, store_op, load_op)                 ;\
-                                                                             ;\
-execute_store_u##store_type:                                                 ;\
-  execute_store_body(store_type, store_op)                                   ;\
-  sub r2, r2, #0x8000                     /* Pointer to code status data   */;\
-  load_op r0, [r2, r0]                    /* check code flag               */;\
-                                                                             ;\
-  cmp r0, #0                              /* see if it's not 0             */;\
-  bne 2f                                  /* if so perform smc write       */;\
-  ldmia sp!, { lr }                       /* restore lr                    */;\
-  restore_flags()                                                            ;\
-  add pc, lr, #4                          /* return                        */;\
-                                                                             ;\
-2:                                                                           ;\
-  ldmia sp!, { lr }                       /* restore lr                    */;\
-  ldr r0, [lr]                            /* load PC                       */;\
-  str r0, [reg_base, #REG_PC]             /* write out PC                  */;\
-  b smc_write                             /* perform smc write             */;\
-1:                                                                           ;\
-  .word memory_map_write                                                     ;\
-                                                                             ;\
-ext_store_u##store_type:                                                     ;\
-  ldmia sp!, { lr }                       /* pop lr off of stack           */;\
-  ldr r2, [lr]                            /* load PC                       */;\
-  str r2, [reg_base, #REG_PC]             /* write out PC                  */;\
-  store_align_##store_type()                                                 ;\
-  call_c_function(write_memory##store_type)                                  ;\
-  b write_epilogue                        /* handle additional write stuff */;\
-
-execute_store_builder(8, strb, ldrb)
-execute_store_builder(16, strh, ldrh)
-execute_store_builder(32, str, ldr)
-
-
-execute_store_u32_safe:
-  execute_store_body(32_safe, str)
-  restore_flags()
-  ldmia sp!, { pc }                       @ return
-
-1:
-  .word memory_map_write
-
-ext_store_u32_safe:
-  ldmia sp!, { lr }                       @ Restore lr
-  call_c_function(write_memory32)         @ Perform 32bit store
-  restore_flags()
-  bx lr                                   @ Return
-
-
-write_epilogue:
-  cmp r0, #0                              @ check if the write rose an alert
-  beq 4f                                  @ if not we can exit
-
-  collapse_flags(r1)                      @ interrupt needs current flags
-
-  cmp r0, #2                              @ see if the alert is due to SMC
-  beq smc_write                           @ if so, goto SMC handler
-
-  ldr r1, [reg_base, #REG_CPSR]           @ r1 = cpsr
-  tst r1, #0x20                           @ see if Thumb bit is set
-  bne 1f                                  @ if so do Thumb update
-
-  store_registers_arm()                   @ save ARM registers
-
-3:
-  bl update_gba                           @ update GBA until CPU isn't halted
-
-  mvn reg_cycles, r0                      @ load new cycle count
-  ldr r0, [reg_base, #REG_PC]             @ load new PC
-  ldr r1, [reg_base, #REG_CPSR]           @ r1 = flags
-  tst r1, #0x20                           @ see if Thumb bit is set
-  bne 2f
-
-  load_registers_arm()
-  call_c_function(block_lookup_address_arm)
-  restore_flags()
-  bx r0                                   @ jump to new ARM block
-
-1:
-  store_registers_thumb()                 @ save Thumb registers
-  b 3b
-
-2:
-  load_registers_thumb()
-  call_c_function(block_lookup_address_thumb)
-  restore_flags()
-  bx r0                                   @ jump to new Thumb block
-
-4:
-  restore_flags()
-  add pc, lr, #4                          @ return
-
-
-smc_write:
-  call_c_function(flush_translation_cache_ram)
-
-lookup_pc:
-  ldr r0, [reg_base, #REG_PC]             @ r0 = new pc
-  ldr r1, [reg_base, #REG_CPSR]           @ r1 = flags
-  tst r1, #0x20                           @ see if Thumb bit is set
-  beq lookup_pc_arm                       @ if not lookup ARM
-
-lookup_pc_thumb:
-  call_c_function(block_lookup_address_thumb)
-  restore_flags()
-  bx r0                                   @ jump to new Thumb block
-
-lookup_pc_arm:
-  call_c_function(block_lookup_address_arm)
-  restore_flags()
-  bx r0                                   @ jump to new ARM block
-
-
-#define sign_extend_u8(reg)
-#define sign_extend_u16(reg)
-#define sign_extend_u32(reg)
-
-#define sign_extend_s8(reg)                                                  ;\
-  mov reg, reg, lsl #24                   /* shift reg into upper 8bits    */;\
-  mov reg, reg, asr #24                   /* shift down, sign extending    */;\
-
-#define sign_extend_s16(reg)                                                 ;\
-  mov reg, reg, lsl #16                   /* shift reg into upper 16bits   */;\
-  mov reg, reg, asr #16                   /* shift down, sign extending    */;\
-
-#define execute_load_op_u8(load_op)                                          ;\
-  mov r0, r0, lsl #17                                                        ;\
-  load_op r0, [r2, r0, lsr #17]                                              ;\
-
-#define execute_load_op_s8(load_op)                                          ;\
-  mov r0, r0, lsl #17                                                        ;\
-  mov r0, r0, lsr #17                                                        ;\
-  load_op r0, [r2, r0]                                                       ;\
-
-#define execute_load_op_u16(load_op)                                         ;\
-  execute_load_op_s8(load_op)                                                ;\
-
-#define execute_load_op_s16(load_op)                                         ;\
-  execute_load_op_s8(load_op)                                                ;\
-
-#define execute_load_op_u16(load_op)                                         ;\
-  execute_load_op_s8(load_op)                                                ;\
-
-#define execute_load_op_u32(load_op)                                         ;\
-  execute_load_op_u8(load_op)                                                ;\
-
-
-#define execute_load_builder(load_type, load_function, load_op, mask)        ;\
-                                                                             ;\
-execute_load_##load_type:                                                    ;\
-  save_flags()                                                               ;\
-  tst r0, mask                            /* make sure address is in range */;\
-  bne ext_load_##load_type                /* if not do ext load            */;\
-                                                                             ;\
-  ldr r2, 1f                              /* r2 = memory_map_read          */;\
-  mov r1, r0, lsr #15                     /* r1 = page index of address    */;\
-  ldr r2, [r2, r1, lsl #2]                /* r2 = memory page              */;\
-                                                                             ;\
-  cmp r2, #0                              /* see if map is ext             */;\
-  beq ext_load_##load_type                /* if so do ext load             */;\
-                                                                             ;\
-  execute_load_op_##load_type(load_op)                                       ;\
-  restore_flags()                                                            ;\
-  add pc, lr, #4                          /* return                        */;\
-                                                                             ;\
-ext_load_##load_type:                                                        ;\
-  ldr r1, [lr]                            /* r1 = PC                       */;\
-  str r1, [reg_base, #REG_PC]             /* update PC                     */;\
-  call_c_function(read_memory##load_function)                                ;\
-  sign_extend_##load_type(r0)             /* sign extend result            */;\
-  restore_flags()                                                            ;\
-  add pc, lr, #4                          /* return                        */;\
-                                                                             ;\
-1:                                                                           ;\
-  .word memory_map_read                                                      ;\
-
-
-execute_load_builder(u8, 8, ldrneb, #0xF0000000)
-execute_load_builder(s8, 8, ldrnesb, #0xF0000000)
-execute_load_builder(u16, 16, ldrneh, #0xF0000001)
-execute_load_builder(s16, 16_signed, ldrnesh, #0xF0000001)
-execute_load_builder(u32, 32, ldrne, #0xF0000000)
-
-
-#define execute_ptr_builder(region, ptr, bits)                               ;\
-                                                                             ;\
-execute_##region##_ptr:                                                      ;\
-  ldr r1, 1f                              /* load region ptr               */;\
-  mov r0, r0, lsl #(32 - bits)            /* isolate bottom bits           */;\
-  mov r0, r0, lsr #(32 - bits)                                               ;\
-  bx lr                                   /* return                        */;\
-                                                                             ;\
-1:                                                                           ;\
-  .word (ptr)                                                                ;\
-
-
-execute_bios_ptr_protected:
-  ldr r1, 1f                              @ load bios read ptr
-  and r0, r0, #0x03                       @ only want bottom 2 bits
-  bx lr                                   @ return
-
-1:
-  .word bios_read_protect
-
-
-@ address = (address & 0x7FFF) + ((address & 0x38000) * 2) + 0x8000;
-
-execute_ewram_ptr:
-  ldr r1, 1f                              @ load ewram read ptr
-  mov r2, r0, lsl #17                     @ isolate bottom 15 bits
-  mov r2, r2, lsr #17
-  and r0, r0, #0x38000                    @ isolate top 2 bits
-  add r0, r2, r0, lsl #1                  @ add top 2 bits * 2 to bottom 15
-  bx lr                                   @ return
-
-1:
-  .word (ewram + 0x8000)
-
-
-@  u32 gamepak_index = address >> 15;
-@  u8 *map = memory_map_read[gamepak_index];
-
-@  if(map == NULL)
-@    map = load_gamepak_page(gamepak_index & 0x3FF);
-
-@  value = address##type(map, address & 0x7FFF)
-
-execute_gamepak_ptr:
-  ldr r1, 1f                              @ load memory_map_read
-  mov r2, r0, lsr #15                     @ isolate top 17 bits
-  ldr r1, [r1, r2, lsl #2]                @ load memory map read ptr
-
-  save_flags()
-  cmp r1, #0                              @ see if map entry is NULL
-  bne 2f                                  @ if not resume
-
-  stmdb sp!, { r0 }                       @ save r0 on stack
-  mov r2, r2, lsl #20                     @ isolate page index
-  mov r0, r2, lsr #20
-  call_c_function(load_gamepak_page)      @ read new page into r0
-
-  mov r1, r0                              @ new map = return
-  ldmia sp!, { r0 }                       @ restore r0
-
-2:
-  mov r0, r0, lsl #17                     @ isolate bottom 15 bits
-  mov r0, r0, lsr #17
-  restore_flags()
-  bx lr                                   @ return
-
-1:
-  .word memory_map_read
-
-
-@ These will store the result in a pointer, then pass that pointer.
-
-execute_eeprom_ptr:
-  save_flags()
-
-  call_c_function(read_eeprom)            @ load EEPROM result
-  add r1, reg_base, #(REG_SAVE & 0xFF00)
-  add r1, r1, #(REG_SAVE & 0xFF)
-  strh r0, [r1]                           @ write result out
-  mov r0, #0                              @ zero out address
-
-  restore_flags()
-  bx lr                                   @ return
-
-
-execute_backup_ptr:
-  save_flags()
-
-  mov r0, r0, lsl #16                     @ only want top 16 bits
-  mov r0, r0, lsr #16
-  call_c_function(read_backup)            @ load backup result
-  add r1, reg_base, #(REG_SAVE & 0xFF00)
-  add r1, r1, #(REG_SAVE & 0xFF)
-  strb r0, [r1]                           @ write result out
-  mov r0, #0                              @ zero out address
-
-  restore_flags()
-  bx lr                                   @ return
-
-
-execute_open_ptr:
-  ldr r1, [reg_base, #REG_CPSR]           @ r1 = cpsr
-  save_flags()
-
-  stmdb sp!, { r0 }                       @ save r0
-
-  ldr r0, [lr, #-4]                       @ r0 = current PC
-
-  tst r1, #0x20                           @ see if Thumb bit is set
-  bne 1f                                  @ if so load Thumb op
-
-  call_c_function(read_memory32)          @ read open address
-
-  add r1, reg_base, #((REG_SAVE + 4) & 0xFF00)
-  add r1, r1, #((REG_SAVE + 4) & 0xFF)
-  add r1, r1, reg_base
-  str r0, [r1]                            @ write out
-
-  ldmia sp!, { r0 }                       @ restore r0
-  and r0, r0, #0x03                       @ isolate bottom 2 bits
-
-  restore_flags()
-  bx lr
-
-1:
-  call_c_function(read_memory16)          @ read open address
-
-  orr r0, r0, r0, lsl #16                 @ duplicate opcode over halves
-  add r1, reg_base, #((REG_SAVE + 4) & 0xFF00)
-  add r1, r1, #((REG_SAVE + 4) & 0xFF)
-
-  add r1, r1, reg_base
-  str r0, [r1]                            @ write out
-
-  ldmia sp!, { r0 }                       @ restore r0
-  and r0, r0, #0x03                       @ isolate bottom 2 bits
-
-  restore_flags();
-  bx lr
-
-
-execute_ptr_builder(bios_rom, bios_rom, 14)
-execute_ptr_builder(iwram, iwram + 0x8000, 15)
-execute_ptr_builder(vram, vram, 17)
-execute_ptr_builder(oam_ram, oam_ram, 10)
-execute_ptr_builder(io_registers, io_registers, 10)
-execute_ptr_builder(palette_ram, palette_ram, 10)
-
-ptr_read_function_table:
-  .word execute_bios_ptr_protected        @ 0x00: BIOS
-  .word execute_open_ptr                  @ 0x01: open
-  .word execute_ewram_ptr                 @ 0x02: ewram
-  .word execute_iwram_ptr                 @ 0x03: iwram
-  .word execute_io_registers_ptr          @ 0x04: I/O registers
-  .word execute_palette_ram_ptr           @ 0x05: palette RAM
-  .word execute_vram_ptr                  @ 0x06: vram
-  .word execute_oam_ram_ptr               @ 0x07: oam RAM
-  .word execute_gamepak_ptr               @ 0x08: gamepak
-  .word execute_gamepak_ptr               @ 0x09: gamepak
-  .word execute_gamepak_ptr               @ 0x0A: gamepak
-  .word execute_gamepak_ptr               @ 0x0B: gamepak
-  .word execute_gamepak_ptr               @ 0x0C: gamepak
-  .word execute_eeprom_ptr                @ 0x0D: EEPROM
-  .word execute_backup_ptr                @ 0x0E: backup
-
-.rept (256 - 15)                          @ 0x0F - 0xFF: open
-  .word execute_open_ptr
-.endr
-
-
-@ Setup the read function table.
-@ Load this onto the the stack; assume we're free to use r3
-
-load_ptr_read_function_table:
-  mov r0, #256                            @ 256 elements
-  ldr r1, 1f                              @ r0 = ptr_read_function_table
-  mov r2, sp                              @ load here
-
-2:
-  ldr r3, [r1], #4                        @ read pointer
-  str r3, [r2], #4                        @ write pointer
-
-  subs r0, r0, #1                         @ goto next iteration
-  bne 2b
-
-  bx lr
-
-1:
-  .word ptr_read_function_table
-
-
-@ Patch the read function table to allow for BIOS reads.
-
-execute_patch_bios_read:
-  ldr r0, 1f                              @ r0 = patch function
-  ldr r1, 2f                              @ r1 = reg
-  ldr r1, [r1]
-  str r0, [r1, #-REG_BASE_OFFSET]
-  bx lr
-
-1:
-  .word execute_bios_rom_ptr
-
-2:
-  .word reg
-
-
-@ Patch the read function table to allow for BIOS reads.
-
-execute_patch_bios_protect:
-  ldr r0, 1f                              @ r0 = patch function
-  ldr r1, 2f                              @ r1 = reg
-  ldr r1, [r1]
-  str r0, [r1, #-REG_BASE_OFFSET]
-  bx lr
-
-1:
-  .word execute_bios_ptr_protected
-
-2:
-  .word reg
-
-
-#define save_reg_scratch(reg)                                                 ;\
-  ldr r2, [reg_base, #(REG_BASE_OFFSET + (reg * 4))]                          ;\
-  str r2, [reg_base, #(REG_BASE_OFFSET + (reg * 4) + 128)]                    ;\
-
-#define restore_reg_scratch(reg)                                              ;\
-  ldr r2, [reg_base, #(REG_BASE_OFFSET + (reg * 4) + 128)]                    ;\
-  str r2, [reg_base, #(REG_BASE_OFFSET + (reg * 4))]                          ;\
-
-#define scratch_regs_thumb(type)                                              ;\
-  type##_reg_scratch(0)                                                       ;\
-  type##_reg_scratch(1)                                                       ;\
-  type##_reg_scratch(2)                                                       ;\
-  type##_reg_scratch(3)                                                       ;\
-  type##_reg_scratch(4)                                                       ;\
-  type##_reg_scratch(5)                                                       ;\
-
-#define scratch_regs_arm(type)                                                ;\
-  type##_reg_scratch(0)                                                       ;\
-  type##_reg_scratch(1)                                                       ;\
-  type##_reg_scratch(6)                                                       ;\
-  type##_reg_scratch(9)                                                       ;\
-  type##_reg_scratch(12)                                                      ;\
-  type##_reg_scratch(14)                                                      ;\
-
-
-step_debug_arm:
-  save_flags()
-  collapse_flags(r0)
-
-  ldr r0, [reg_base, #REG_CPSR]           @ r1 = cpsr
-  tst r0, #0x20                           @ see if Thumb bit is set
-
-  ldr r0, [lr]                            @ load PC
-  mvn r1, reg_cycles                      @ load cycle counter
-
-  beq 1f                                  @ if not goto ARM mode
-
-  scratch_regs_thumb(save)
-
-  store_registers_thumb()                 @ write back Thumb regs
-  call_c_function(step_debug)             @ call debug step
-  scratch_regs_thumb(restore)
-  restore_flags()
-  add pc, lr, #4                          @ return
-
-1:
-  scratch_regs_arm(save)
-  store_registers_arm()                   @ write back ARM regs
-  call_c_function(step_debug)             @ call debug step
-  scratch_regs_arm(restore)
-  restore_flags()
-  add pc, lr, #4                          @ return, skipping PC
-
-
-.comm memory_map_read 0x8000
-.comm memory_map_write 0x8000
-
-
-