diff options
Diffstat (limited to 'x86/x86_stub.S')
| -rw-r--r-- | x86/x86_stub.S | 44 |
1 files changed, 40 insertions, 4 deletions
diff --git a/x86/x86_stub.S b/x86/x86_stub.S index dd98f7a..ba997ba 100644 --- a/x86/x86_stub.S +++ b/x86/x86_stub.S @@ -95,6 +95,7 @@ .equ CPU_MODE, (29 * 4) .equ CPU_HALT_STATE, (30 * 4) .equ CHANGED_PC_STATUS, (31 * 4) +.equ COMPLETED_FRAME, (32 * 4) # destroys ecx and edx @@ -150,6 +151,11 @@ _x86_update_gba: call _update_gba # process the next event mov %eax, %edi # edi = new cycle count + + # did we just complete a frame? go back to main then + cmpl $0, COMPLETED_FRAME(%ebx) + jne return_to_main + # did the PC change? cmpl $1, CHANGED_PC_STATUS(%ebx) je lookup_pc @@ -197,6 +203,10 @@ write_epilogue: alert_loop: call _update_gba # process the next event + + # did we just complete a frame? go back to main then + cmpl $0, COMPLETED_FRAME(%ebx) + jne return_to_main # see if the halt status has changed mov CPU_HALT_STATE(%ebx), %edx @@ -509,24 +519,50 @@ lookup_pc_arm: # eax: cycle counter _execute_arm_translate: - movl (_reg), %ebx # load base register + # Save main context, since we need to return gracefully + pushl %ebx + pushl %esi + pushl %edi + pushl %ebp + + movl $_reg, %ebx # load base register extract_flags # load flag variables movl %eax, %edi # load edi cycle counter movl REG_PC(%ebx), %eax # load PC + # (if the CPU is halted, do not start executing but + # loop in the alert loop until it wakes up) + cmp $0, CPU_HALT_STATE(%ebx) + je 1f + call alert_loop # Need to push something to the stack + +1: testl $0x20, REG_CPSR(%ebx) - jnz 1f + jnz 2f call _block_lookup_address_arm jmp *%eax # jump to it -1: +2: call _block_lookup_address_thumb jmp *%eax +return_to_main: + add $4, %esp # remove current return addr + popl %ebp + popl %edi + popl %esi + popl %ebx + ret + +.data +.align 64 + +_reg: + .space 0x100, 0 + .comm _memory_map_read 0x8000 .comm _memory_map_write 0x8000 -.comm _reg 4 |