1############################################################################### 2# 3# 16550 serial Rx interrupt handler for gdbstub I/O 4# 5# Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 6# Written by David Howells (dhowells@redhat.com) 7# 8# This program is free software; you can redistribute it and/or 9# modify it under the terms of the GNU General Public Licence 10# as published by the Free Software Foundation; either version 11# 2 of the Licence, or (at your option) any later version. 12# 13############################################################################### 14#include <linux/sys.h> 15#include <linux/linkage.h> 16#include <asm/smp.h> 17#include <asm/cpu-regs.h> 18#include <asm/thread_info.h> 19#include <asm/frame.inc> 20#include <asm/intctl-regs.h> 21#include <unit/serial.h> 22 23 .text 24 25############################################################################### 26# 27# GDB stub serial receive interrupt entry point 28# - intended to run at interrupt priority 0 29# 30############################################################################### 31 .globl gdbstub_io_rx_handler 32 .type gdbstub_io_rx_handler,@function 33gdbstub_io_rx_handler: 34 movm [d2,d3,a2,a3],(sp) 35 36 movbu (GDBPORT_SERIAL_IIR),d2 37 38 mov (gdbstub_rx_inp),a3 39gdbstub_io_rx_more: 40 mov a3,a2 41 add 2,a3 42 and 0x00000fff,a3 43 mov (gdbstub_rx_outp),d3 44 cmp a3,d3 45 beq gdbstub_io_rx_overflow 46 47 movbu (GDBPORT_SERIAL_LSR),d3 48 btst UART_LSR_DR,d3 49 beq gdbstub_io_rx_done 50 movbu (GDBPORT_SERIAL_RX),d2 51 movbu d3,(gdbstub_rx_buffer+1,a2) 52 movbu d2,(gdbstub_rx_buffer,a2) 53 mov a3,(gdbstub_rx_inp) 54 bra gdbstub_io_rx_more 55 56gdbstub_io_rx_done: 57 mov GxICR_DETECT,d2 58 movbu d2,(XIRQxICR(GDBPORT_SERIAL_IRQ)) # ACK the interrupt 59 movhu (XIRQxICR(GDBPORT_SERIAL_IRQ)),d2 # flush 60 movm (sp),[d2,d3,a2,a3] 61 bset 0x01,(gdbstub_busy) 62 beq gdbstub_io_rx_enter 63 rti 64 65gdbstub_io_rx_overflow: 66 bset 0x01,(gdbstub_rx_overflow) 67 bra gdbstub_io_rx_done 68 69gdbstub_io_rx_enter: 70 or EPSW_IE|EPSW_IM_1,epsw 71 add -4,sp 72 SAVE_ALL 73 74 mov 0xffffffff,d0 75 mov d0,(REG_ORIG_D0,fp) 76 mov 0x280,d1 77 78 mov fp,d0 79 call gdbstub_rx_irq[],0 # gdbstub_rx_irq(regs,excep) 80 81 and ~EPSW_IE,epsw 82 bclr 0x01,(gdbstub_busy) 83 84 .globl gdbstub_return 85gdbstub_return: 86 RESTORE_ALL 87 88 .size gdbstub_io_rx_handler,.-gdbstub_io_rx_handler 89