/** @file debug_stub.S * @brief ARM Breakpoint Debugger support routines * */ /* Copyright (C) 2007-2011 the NxOS developers * * Module Developed by: TC Wan * * See AUTHORS for a full list of the developers. * * See COPYING for redistribution license * */ /* GDB sparc-stub.c comments header included below to document GDB Server Remote protocol */ /* This header has been modified to include additional commands not documented in the header stub */ /**************************************************************************** THIS SOFTWARE IS NOT COPYRIGHTED HP offers the following for use in the public domain. HP makes no warranty with regard to the software or it's performance and the user accepts the software "AS IS" with all faults. HP DISCLAIMS ANY WARRANTIES, EXPRESS OR IMPLIED, WITH REGARD TO THIS SOFTWARE INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. ****************************************************************************/ /**************************************************************************** * Header: remcom.c,v 1.34 91/03/09 12:29:49 glenne Exp $ * * Module name: remcom.c $ * Revision: 1.34 $ * Date: 91/03/09 12:29:49 $ * Contributor: Lake Stevens Instrument Division$ * * Description: low level support for gdb debugger. $ * * Considerations: only works on target hardware $ * * Written by: Glenn Engel $ * ModuleState: Experimental $ * * NOTES: See Below $ * * Modified for SPARC by Stu Grossman, Cygnus Support. * * This code has been extensively tested on the Fujitsu SPARClite demo board. * * To enable debugger support, two things need to happen. One, a * call to set_debug_traps() is necessary in order to allow any breakpoints * or error conditions to be properly intercepted and reported to gdb. * Two, a breakpoint needs to be generated to begin communication. This * is most easily accomplished by a call to breakpoint(). Breakpoint() * simulates a breakpoint by executing a trap #1. * ************* * * The following gdb commands are supported: * * command function Return value * * g return the value of the CPU registers hex data or ENN * GrrrrRRRR.. set the value of the CPU registers OK or ENN * where register values are given as * 32-bit hex values in the sequence: * User R0, R1, ..., R15, CPSR * px get the value of one register (x) hex data or ENN * Px=rrrr set the value of one register (x) to OK or ENN * 32-bit hex value rrrr. * x = ['0','F'] for R0-R15, ['10','17'] for F0-F7 (dummy) * '18' for FPSCR (dummy), '19' for User CPSR * * mAA..AA,LLLL Read LLLL bytes at address AA..AA hex data or ENN * MAA..AA,LLLL:bb..bb * Write LLLL bytes at address AA.AA OK or ENN * * D Detach (equivalent to continue Ack Only * at current address) * c Resume at current address SNN ( signal NN) * cAA..AA Continue at address AA..AA SNN * * s Step one instruction SNN * sAA..AA Step one instruction from AA..AA SNN * * k kill * * ? What was the last sigval ? SNN (signal NN) * * zt,AA..AA,k Remove a Breakpoint of type t at addr OK or ENN * AA..AA of kind k * Zt,AA..AA,k Insert a Breakpoint of type t at addr OK or ENN * AA..AA of kind k * t 0: memory breakpoint * 1: hardware breakpoint * 2: write watchpoint * 3: read watchpoint * 4: access watchpoint * k: 2 (16-bit Thumb), 3 (32-bit Thumb2) * or 4 (32-bit ARM) for t=[0,1] * Num. bytes to watch for t=[2,4] * * All commands and responses are sent with a packet which includes a * checksum. A packet consists of * * $#. * * where * :: * :: < two hex digits computed as modulo 256 sum of > * * When a packet is received, it is first acknowledged with either '+' or '-'. * '+' indicates a successful transfer. '-' indicates a failed transfer. * * Example: * * Host: Reply: * $m0,10#2a +$00010203040506070809101112131415#42 * ****************************************************************************/ /* Modified GDB Server Remote Protocol definition from GDB's sparc-stub.c Comment Header included above * Additional commands from GDB Reference Appendix D.2 * * Note: ARMDEBUG can only implement Memory Breakpoints t=0. Hardware breakpoints requires a JTAG debugger. * Currently, watchpoints are not implemented as they require hardware support as well (need verification). * * GDB requires command parameters to be specified as Big Endian values. * However, the read/write register command expect the register contents to be specified in target byte order. * The default target byte order is Little Endian for the AT91SAM7xxx processor in the NXT. * If Big Endian target byte order is required, the __BIG_ENDIAN__ preprocessor label should be defined. */ /* FIXME: The Hex value arguments passed by GDB does not have fixed lengths! Although the standard says * there should be x digits, it does not follow this requirement. e.g., register index. */ #define __ASSEMBLY__ #include "debug_stub.h" #include "debug_internals.h" #include "debug_macros.h" /* Opcode Parser function reference */ .extern dbg_following_instruction_addr /* Hexutils function references */ .extern hex2char .extern char2hex .extern byte2ascii .extern halfword2ascii_be .extern halfword2ascii_le .extern word2ascii_be .extern word2ascii_le .extern ascii2hex_varlen_be .extern ascii2byte .extern ascii2halfword_be .extern ascii2halfword_le .extern ascii2word_be .extern ascii2word_le /* Macro definitions */ /* _check_msgseparator * Look for separator ',' * On entry: * bufferptr: points to the parameter buffer [can't be R0] * On exit: * R0: destroyed * bufferptr: points to the next character location in the parameter buffer * Flags: Updated */ .macro _check_msgseparator bufferptr ldrb r0, [\bufferptr], #1 /* get separator */ cmp r0, #MSGBUF_SEPCHAR .endm /* _check_msgargument * Look for argument ':' * On entry: * bufferptr: points to the parameter buffer [can't be R0] * On exit: * R0: destroyed * bufferptr: points to the next character location in the parameter buffer * Flags: Updated */ .macro _check_msgargument bufferptr ldrb r0, [\bufferptr], #1 /* get separator */ cmp r0, #MSGBUF_ARGCHAR .endm /* _check_msgassignment * Look for assignment '=' * On entry: * bufferptr: points to the parameter buffer [can't be R0] * On exit: * R0: destroyed * bufferptr: points to the next character location in the parameter buffer * Flags: Updated */ .macro _check_msgassignment bufferptr ldrb r0, [\bufferptr], #1 /* get separator */ cmp r0, #MSGBUF_SETCHAR .endm .bss .align 4 debug_InMsgBuf: .space MSGBUF_SIZE,0 debug_OutMsgBuf: .space MSGBUF_SIZE,0 /* Make Debugger State accessible from other modules */ .global debug_state .global debug_mode .global debug_bkpt_type .global debug_curr_breakpoint debug_state: .byte 0x0 /* dbg_state_t variable */ debug_mode: .byte 0x0 /* Boolean variable */ debug_bkpt_type: .byte 0x0 /* bkpt_type_t variable */ debug_curr_breakpoint: .byte 0x0 .data .align 4 debug_RetransmitFlag: .byte '-',0 debug_AckOnlyFlag: .byte '+',0 debug_ValidResponsePrefix: .byte '+','$',0 debug_ErrorResponsePrefix: .byte '+','$','E',0 debug_SignalResponsePrefix: .byte '+','$','S',0 debug_OkResponse: .byte '+','$','O','K',0 debug_ThreadIDResponse: .byte '+','$','Q','C','0',0 /* 0: Any thread */ debug_FirstThreadInfoResponse: .byte '+','$','m','0',0 /* 0: One default thread */ debug_SubsequentThreadInfoResponse: .byte '+','$','l',0 /* End of Thread List */ /* The CmdIndexTable and CmdJumpTable must be kept in sync */ debug_cmdIndexTable: .byte 'g','G','p','P','m','M','D','c','s','k','z','Z','?','q','Q',0 /* Command Handlers * On entry: * R0: Input Message Parameter Buffer address pointer (points to contents after '$' and '') */ .align 4 debug_cmdJumpTable: .word _dbg__cmd_GetAllRegs /* 'g' */ .word _dbg__cmd_SetAllRegs /* 'G' */ .word _dbg__cmd_GetOneReg /* 'p' */ .word _dbg__cmd_SetOneReg /* 'P' */ .word _dbg__cmd_ReadMem /* 'm' */ .word _dbg__cmd_WriteMem /* 'M' */ .word _dbg__cmd_Detach /* 'D' */ .word _dbg__cmd_Continue /* 'c' */ #ifdef __NXOS__ .word _dbg__cmd_Step /* 's' */ #else /* NXT Firmware does not support Stepping */ .word _dbg__nop /* 's' */ #endif .word _dbg__cmd_Kill /* 'k' */ .word _dbg__cmd_RemoveBreakpoint /* 'z' */ .word _dbg__cmd_InsertBreakpoint /* 'Z' */ .word _dbg__cmd_Status /* '?' */ .word _dbg__cmd_Query /* 'q' */ .word _dbg__nop /* 'Q' */ .word 0 .code 32 .text .align 4 .extern __breakpoints_num__ .extern dbg__getDebugMsg /* Read a message from the communications link */ .extern dbg__putDebugMsg /* Write a message to the communications link */ .extern dbg__sendAckOrNak /* Send Ack or Nak to indicate success/failure of message receipt */ .extern dbg__runloopTasks /* Platform specific Run Loop processing */ /* The Debugger Interface can handle a total of (n-1) Breakpoint States and 1 Single Stepping State, * where n is a power of 2. The value of n is given by __breakpoints_num__ defined in the linker file. * * In addition, a Debugger Stack contains the User Mode Register Stack Frame + SPSR + Bkpt Instr Addr. * These are currently stored in the .stack area in RAM, so there is no fixed address * location that is used for this purpose. * * The Breakpoint feature assumes that the program is executed in RAM. It is not possible * to set dynamic breakpoints for programs executed from Flash in the AT91SAM7S which lacks * instruction breakpointing support in hardware without using JTAG. The only type of breakpoints * that can be supported in Flash based programs are Static (predefined) breakpoints inserted into * the code. * * Each Breakpoint State i is a struct comprising the Breakpoint Address + Memory Contents * stored in 8 bytes as: * [High Memory Address] * ADDR [i*8+4]: Memory Contents (32 bits) * ADDR [i*8]: Breakpoint Address (31 bits, b0 = THUMB flag [not implemented yet]) * [Low Memory Address] * * A Non-zero Breakpoint Address means that the breakpoint is active, whereas the memory contents * contains the instruction which resided at that address initially (now replaced by a BKPT * instruction). * Note: Currently it is not possible to resume execution of a program with breakpoints enabled * after a RESET, since the RESET will clear all contents of the stack, destroying the instruction * contained in a given breakpoint. * Fortunately the NXT will also need to reload the program into RAM so this is not expected to be * an issue. * * The Memory Map for the Debugger State is as follows: * * [High Memory Address] __breakpoints_end__ * Breakpoint 07 State * Breakpoint 06 State * ... * Breakpoint 02 State * Breakpoint 01 State * Single Step State __debugger_stack__ / __breakpoints_start__ * Previous Mode R15 * Previous Mode R14 * Previous Mode R13 * ... * User Mode R02 * User Mode R01 * User Mode R00 * Previous Mode CPSR (UNDEF SPSR) * UNDEF Next Instr Addr __debugger_stack_bottom__ * [Low Memory Address] * * Each Breakpoint State will initially be zeroed. * */ /* FIXME: The Debugger Stack Frame is probably not 100% consistent with the order that GDB expects in the g/G messages. CSPR is probably located above R15 */ /**************************************************************************** * * GDB Debugger Init and Breakpoint Handler Routines * ****************************************************************************/ .code 32 .align 4 /* dbg__bkpt_init * GDB set_debug_traps() routine * On entry: * None * On exit: * r0-r3: destroyed */ .global dbg__bkpt_init dbg__bkpt_init: push {lr} bl _dbg__clear_breakpoints mov r2, #0 ldr r1, =debug_curr_breakpoint strb r2, [r1] ldr r0, =debug_InMsgBuf strb r2, [r0] ldr r1, =debug_OutMsgBuf strb r2, [r1] bl dbg__comm_init /* Pass R0: Rx Buffer, R1: Tx Buffer to comm submodule */ /* FIXME: Initialize other stuff here */ _dbg_setstate DBG_INIT _dbg_setmode FALSE /* Debug Mode = False */ pop {lr} bx lr /* Must return via BX; may have been called from Thumb mode (NXT Firmware) */ /* _dbg__flush_icache * Flush the Instruction cache * Defined by GDB Stub, but not needed for ARMv4T architecture */ _dbg__flush_icache: /* nop */ bx lr /* _dbg__switch2undefmode * Common internal routine to return execution to user program */ _dbg__switch2undefmode: bl _dbg__flush_icache msr cpsr_c, #(MODE_UND | CPSR_FIQ | CPSR_IRQ) /* Configure Undef Mode */ _dbg_setmode FALSE /* Debug Mode = False */ ldr lr, =resume_execution mov pc, lr /* Exit via UNDEF mode */ /* dbg__abort_exception_handler * Handle Abort Exceptions * On entry: * r0: Abort Type Enum * On exit: * routine does not 'exit' in the normal sense */ .global dbg__abort_exception_handler dbg__abort_exception_handler: _dbg_set_bkpt_type r0 /* Set Breakpoint Type given value in R0 */ b dbg__bkpt_waitCMD /* dbg__thumb_bkpt_handler * GDB handle_exception() routine (Thumb Mode) * On entry: * r0: Breakpoint index value * On exit: * routine does not 'exit' in the normal sense */ .global dbg__thumb_bkpt_handler dbg__thumb_bkpt_handler: /* On entry, r0 contains breakpoint index value */ _dbg_setcurrbkpt_index r0 /* keep current breakpoint index in memory */ ldr r1, =BKPT16_MANUAL_BKPT teq r0, r1 moveq r0, #DBG_MANUAL_BKPT_THUMB /* Manual Thumb Breakpoint, process it */ beq _restore_normal_breakpoints _process_normal_breakpoint_thumb: ldr r1, =__breakpoints_num__ cmp r0, r1 /* Sanity check that index is in range */ bhs dbg__bkpt_offset_outofrange /* Exceeded Offset Range */ mov r0, #DBG_NORMAL_BKPT_THUMB /* It is a valid normal breakpoint */ b _restore_normal_breakpoints /* dbg__arm_bkpt_handler * GDB handle_exception() routine (ARM Mode) * On entry: * r0: breakpoint index value * On exit: * routine does not 'exit' in the normal sense */ .global dbg__arm_bkpt_handler dbg__arm_bkpt_handler: /* On entry, r0 contains breakpoint index value */ _dbg_setcurrbkpt_index r0 /* keep current breakpoint index in memory */ ldr r1, =BKPT32_MANUAL_BKPT teq r0, r1 moveq r0, #DBG_MANUAL_BKPT_ARM /* Manual ARM Breakpoint, process it */ beq _restore_normal_breakpoints _process_normal_breakpoint_arm: ldr r1, =__breakpoints_num__ cmp r0, r1 /* Sanity check that index is in range */ bhs dbg__bkpt_offset_outofrange /* Exceeded Offset Range */ mov r0, #DBG_NORMAL_BKPT_ARM /* It is a valid normal breakpoint */ /* b _restore_normal_breakpoints */ _restore_normal_breakpoints: _dbg_set_bkpt_type r0 /* Set Breakpoint Type given value in R0 */ bl _dbg__restore_breakpoints /* includes restoring single step */ bl _dbg__clear_singlestep bl _dbg__flush_icache /* b dbg__bkpt_waitCMD */ dbg__bkpt_inactive: /* b dbg__bkpt_waitCMD */ dbg__bkpt_offset_outofrange: /* b dbg__bkpt_waitCMD */ .global dbg__bkpt_waitCMD /* dbg__bkpt_waitCMD * GDB Stub Remote Command Handler */ /**************************************************************************** * * GDB Server Command Processing Routines * ****************************************************************************/ dbg__bkpt_waitCMD: /* We enter this code section when a Breakpoint Triggers */ _dbg_setmode TRUE /* Debug Mode = True */ msr cpsr_c, #(MODE_ABT) /* Re-enable Interrupts */ _dbg_getstate r0 cmp r0, #DBG_CONFIGURED blo dbg__bkpt_waitCMD_cont /* Not configured yet, don't send Breakpoint Signal Response */ bl _dbg__cmd_Status /* Send signal response to the GDB server */ dbg__bkpt_waitCMD_cont: bl dbg__runloopTasks /* Execute housekeeping tasks while in ABRT mode */ bl dbg__getDebugMsg /* Read new message from Debugger, buflen in R0, 0 if none, -1 if error, msgbuf pointer in R1 */ cmp r0, #0 beq dbg__bkpt_waitCMD_cont /* No message yet, do housekeeping tasks */ bgt _proc_command /* valid message, process it */ bl __dbg__procChecksumError /* Message invalid, checksum error? */ b dbg__bkpt_waitCMD_cont _proc_command: /* Message now has Ctrl-C or $\0 */ mov r4, r1 /* Use R4 as buffer pointer */ ldrb r0, [r4], #1 /* Look for Ctrl-C or '$' */ teq r0, #MSGBUF_CTRLC bne _dbg_check_gdb_command /* Ctrl-C detected, do nothing (wait for next command from GDB) */ #if 0 /* On entering the Debugger via Ctrl-C, _dbg__cmd_Status has already sent a reply, so just keep quiet */ bl __dbg__procAckOnly /* send Ack */ #endif b dbg__bkpt_waitCMD_cont _dbg_check_gdb_command: teq r0, #MSGBUF_STARTCHAR movne r1, #MSG_ERRFORMAT /* Message Format invalid (not '$') */ bne _dbg__cmdError /* Shouldn't happen */ ldrb r0, [r4], #1 /* Look for command char */ bl _dbg__cmdChar2Index /* Index in R0 */ mov r1, #CMDINDEX_OUTOFRANGE teq r0, r1 bne _dbg__cmdExists /* Found valid command, execute it */ _dbg_unknown_command: bl _dbg__nop /* Command character not recognized, send empty response to GDB server */ b dbg__bkpt_waitCMD_cont #if 0 moveq r1, #MSG_UNKNOWNCMD /* Out of range, Command character not recognized */ beq _dbg__cmdError /* Send response to GDB server */ #endif _dbg__cmdExists: mov r3, r0 /* put Command Handler Index in R3 */ mov r0, r4 /* R0 now contains Input Message Buffer Parameter Pointer (previously in R4) */ _dbg_jumpTableHandler debug_cmdJumpTable, r2, r3 /* Call Command Handler Routine, use R2 as jump address pointer */ b dbg__bkpt_waitCMD_cont _dbg__cmdError: _dbg_outputMsgStatusErr bl dbg__putDebugMsg /* Send error response to the GDB server */ b dbg__bkpt_waitCMD_cont /* __dbg__procOkOnly * Send OK to GDB due to Detach * On entry: * None * On exit: * r0-r3: destroyed */ __dbg__procOkOnly: stmfd sp!, {lr} _dbg_outputMsgStatusOk /* Acknowledge Detach command from GDB server */ _cont_procOkOnly: bl dbg__putDebugMsg /* Send OK response to the GDB server */ cmp r0, #0 beq _cont_procOkOnly_exit /* Sending of OK succeeded */ bl dbg__runloopTasks /* Service run loop tasks */ b _cont_procOkOnly /* Retry OK transmission */ _cont_procOkOnly_exit: ldmfd sp!, {pc} /* __dbg__procAckOnly * Send Ack to GDB due to Continue or Step * On entry: * None * On exit: * r0-r3: destroyed */ __dbg__procAckOnly: stmfd sp!, {lr} _dbg_outputAckOnlyFlag b _cont_sendAckOrNak /* Acknowledge Continue or Step command from GDB server */ /* __dbg__procChecksumError * Request Retransmission from GDB due to Checksum error * On entry: * None * On exit: * r0-r3: destroyed */ __dbg__procChecksumError: stmfd sp!, {lr} _dbg_outputRetransmitFlag /* b _cont_sendAckOrNak */ /* Acknowledge Continue or Step command from GDB server */ _cont_sendAckOrNak: bl dbg__sendAckOrNak /* send Ack or Nak to GDB server */ cmp r0, #0 beq _cont_sendAckOrNak_exit /* Sending of Ack or Nak succeeded */ bl dbg__runloopTasks /* Service run loop tasks */ b _cont_sendAckOrNak /* Retry Ack or Nak transmission */ _cont_sendAckOrNak_exit: ldmfd sp!, {pc} /* _dbg__cmdChar2Index * Convert Command Character to Jump Table Index * On entry: * r0: command character * On exit: * r0: jump table index (-1 for command not found) * R1: destroyed * R2: destroyed * R3: destroyed */ _dbg__cmdChar2Index: mov r1, r0 /* Copy command character to r1 */ mov r0, #0 /* Clear return value */ ldr r3, =debug_cmdIndexTable /* Convert command to index using r3 as Index Lookup Address Pointer */ 1: ldrb r2, [r3, r0] /* Get table entry */ teq r2, #0 moveq r0, #CMDINDEX_OUTOFRANGE /* End of Index Table, Not found */ beq _exit_cmdIndexTable teq r1, r2 addne r0, #1 /* Increment Index */ bne 1b /* No match, skip to next command char */ _exit_cmdIndexTable: bx lr /* __dbg__cmdParamLen * Determines the length of the parameter buffer for a given command * On entry: * R0: parameter buffer pointer (contents after '$' and '') * On exit: * R0: Address of parameter buffer (preserved) * R1: length */ __dbg__cmdParamLen: stmfd sp!, {r0,r2,lr} /* R2: scratch register */ mov r1, #0 1: ldrb r2, [r0], #1 teq r2, #0 addne r1, r1, #1 bne 1b ldmfd sp!, {r0,r2,pc} /* __dbg__procCmdOk * Common subroutine exit stub to return Command Ok Status for Command Handlers * DO NOT CALL THIS STUB DIRECTLY! It Assumes that the return address is in the stack. * */ __dbg__procCmdOk: _dbg_outputMsgStatusOk b __dbg__sendDebugMsgExit /* __dbg__procUnimplementedError * Common subroutine exit stub to handle Unimplemented GDB Command Error * DO NOT CALL THIS STUB DIRECTLY! It Assumes that the return address is in the stack. * Note: GDB Remote Protocol specifies returning blank message ('+$') * */ __dbg__procUnimplementedError: _dbg_outputMsgValidResponse b __dbg__sendDebugMsgExit /* __dbg__procCmdParamError * Common subroutine exit stub to handle Command Parameter Error for Command Handlers * DO NOT CALL THIS STUB DIRECTLY! It Assumes that the return address is in the stack. * */ __dbg__procCmdParamError: mov r1, #MSG_UNKNOWNPARAM b __dbg__procErrorMsg /* __dbg__procCmdReturnInputLengthError * Common subroutine exit stub to handle Command Input Length Error for Command Handlers * DO NOT CALL THIS STUB DIRECTLY! It Assumes that the return address is in the stack. * */ __dbg__procCmdReturnInputLengthError: mov r1, #MSG_ERRINLENGTH b __dbg__procErrorMsg /* __dbg__procCmdReturnOutputLengthError * Common subroutine exit stub to handle Command Return Output Error for Command Handlers * DO NOT CALL THIS STUB DIRECTLY! It Assumes that the return address is in the stack. * */ __dbg__procCmdReturnOutputLengthError: mov r1, #MSG_ERROUTLENGTH b __dbg__procErrorMsg /* __dbg__procBreakpointAddrError * Common subroutine exit stub to handle Breakpoint Address Error for Breakpoint Insert/Remove Handlers * DO NOT CALL THIS STUB DIRECTLY! It Assumes that the return address is in the stack. * */ __dbg__procBreakpointAddrError: mov r1, #MSG_UNKNOWNBRKPT /* b __dbg__procErrorMsg */ __dbg__procErrorMsg: _dbg_outputMsgStatusErr /* b __dbg__sendDebugMsgExit */ __dbg__sendDebugMsgExit: bl dbg__putDebugMsg /* Send error response to the GDB server */ ldmfd sp!, {pc} /* _dbg__cmd_Status * Status Command Handler * On entry: * r0: parameter buffer (contents after '$' and '') * On exit: * r0, r1, r2, r3: destroyed */ _dbg__cmd_Status: stmfd sp!, {lr} _dbg_get_bkpt_type r0 _check_data_abort_exception: teq r0, #DBG_ABORT_DATA moveq r1, #MSG_SIG_BUS /* Bus Error */ beq _exit_dmg__cmd_Status _check_prefetch_abort_exception: teq r0, #DBG_ABORT_PREFETCH moveq r1, #MSG_SIG_ABRT /* FIMXE: Look for a better Signal number */ beq _exit_dmg__cmd_Status _default_breakpoint_exception: mov r1, #MSG_SIG_DEFAULT /* Dummy Signal number */ _exit_dmg__cmd_Status: _dbg_outputMsgStatusSig b __dbg__sendDebugMsgExit /* _dbg__cmd_Query * Query Command Handler * On entry: * r0: parameter buffer (contents after '$' and '') * [varied, see GDB General Packets query docs] * http://sourceware.org/gdb/current/onlinedocs/gdb/General-Query-Packets.html * On exit: * r0, r1, r2, r3: destroyed */ _dbg__cmd_Query: stmfd sp!, {r0,r1, lr} _dbg_setstate DBG_CONFIGURED /* We have exchanged query messages with the GDB server */ ldmfd sp!, {r0, r1} /* Restore parameters needed for subsequent processing */ bl __dbg__cmdParamLen cmp r1, #CMD_QUERY_MINPARAMLEN beq _dbg__cmd_Query_default ldrb r2, [r0] /* Get First Query Param Char */ _dbg__cmd_Query_check_C: teq r2, #CMD_QUERY_CURRTID_CHAR /* Handle Current Thread ID Query */ bne _dbg__cmd_Query_check_fThreadInfo cmp r1, #CMD_QUERY_CURRTID_PARAMLEN bne _dbg__cmd_Query_default _dbg_outputMsgCurrTID b __dbg__sendDebugMsgExit _dbg__cmd_Query_check_fThreadInfo: teq r2, #CMD_QUERY_FTINFO_CHAR /* Handle fThreadInfo Query */ bne _dbg__cmd_Query_check_sThreadInfo cmp r1, #CMD_QUERY_FTINFO_PARAMLEN bne _dbg__cmd_Query_default _dbg_outputMsgFirstThreadInfo b __dbg__sendDebugMsgExit _dbg__cmd_Query_check_sThreadInfo: teq r2, #CMD_QUERY_STINFO_CHAR /* Handle sThreadInfo ID Query */ bne _dbg__cmd_Query_default cmp r1, #CMD_QUERY_STINFO_PARAMLEN bne _dbg__cmd_Query_default _dbg_outputMsgSubsequentThreadInfo b __dbg__sendDebugMsgExit _dbg__cmd_Query_default: b __dbg__procUnimplementedError /* FIXME: return an empty message to GDB (no modifiable settings) */ /* _dbg__cmd_GetOneReg * Get One Register Value Command Handler * Valid command parameter x is from '0' to 'F' for User Mode Registers R0-R15, * '18' for FPSCR (dummy), and '19' for CPSR * On entry: * r0: parameter buffer pointer (contents after '$' and '') * x * On exit: * r0, r1, r2, r3, r4: destroyed * */ _dbg__cmd_GetOneReg: stmfd sp!, {lr} bl __dbg__cmdParamLen cmp r1, #CMD_REG_GETONE_MINPARAMLEN /* Check for correct length */ blo __dbg__procCmdParamError /* Unexpected input, report error */ cmp r1, #CMD_REG_GETONE_MAXPARAMLEN /* Check for correct length */ bhi __dbg__procCmdParamError /* Unexpected input, report error */ bl ascii2hex_varlen_be /* convert ASCII reg enum to Hex (in R0), R1 has address of next buffer char */ _dbg__proc_getRegister: mov r4, r0 /* Keep register index safe */ _dbg_outputMsgValidResponse /* R0: address of output message buffer data pointer (after response prefix) */ mov r1, r4 /* Move register index value to R1 */ bl _dbg_outputOneRegValue /* update output buffer */ _asciiz r0, r1 bl dbg__putDebugMsg /* Send response to the GDB server */ ldmfd sp!, {pc} /* _dbg_outputOneRegValue * Given Register Enum (0-F: R0-R15, 0x19: CPSR, OtherVal: dummy), output hex char to buffer * On entry: * r0: output message buffer pointer * r1: register enum (0-F, 0x19) * On exit: * r0: updated (points to next character slot at end of Output Buffer) * r1: original output message buffer pointer * r2: destroyed */ _dbg_outputOneRegValue: stmfd sp!, {lr} cmp r1, #REG_PC addls r2, r1, #DBGSTACK_USERREG_INDEX /* Convert register enum to Debug Stack index */ bls _retrieve_RegVal cmp r1, #REG_CPSR moveq r2, #DBGSTACK_USERCPSR_INDEX /* convert register enum to Debug Stack index */ beq _retrieve_RegVal bhi _exit_dbg_outputOneRegValue /* No match (reg enum > REG_CPSR), skip */ #if 0 cmp r1, #REG_FPSCR bne _exit_dbg_outputOneRegValue /* No match, skip */ #endif _output_dummy_regval: /* Output Dummy Register value (for F0-F7, FPSR) */ mov r1, #0 b _output2buffer /* Output all zeros for F0-F7, FPSCR */ _retrieve_RegVal: _getdbgregisterfromindex r2, r1 /* Retrieve Register contents into R1 */ _output2buffer: #ifdef __BIG_ENDIAN__ bl word2ascii_be /* Convert and put hex chars into Output Message Buffer */ #else bl word2ascii_le /* Convert and put hex chars into Output Message Buffer */ #endif _exit_dbg_outputOneRegValue: ldmfd sp!, {pc} /* _dbg__cmd_GetAllRegs * Get All Register Values Command Handler * Output Buffer returns register values in the order: User R0, R1, R2, ..., R15, CPSR * On entry: * r0: parameter buffer pointer (contents after '$' and '') * (no parameters) * On exit: * r0, r1, r2, r3: destroyed */ _dbg__cmd_GetAllRegs: stmfd sp!, {lr} bl __dbg__cmdParamLen teq r1, #CMD_REG_GETALL_PARAMLEN /* Check for correct length */ bne __dbg__procCmdParamError /* Unexpected input, report error */ _dbg_outputMsgValidResponse /* R0: address of output message buffer data pointer (after response prefix) */ /* We must return R0-R15, then CPSR */ mov r3, #REG_R0 /* Output User Register Values first */ 1: mov r1, r3 bl _dbg_outputOneRegValue /* update output buffer */ add r3, r3, #1 /* increment index */ cmp r3, #REG_PC bls 1b /* process all the registers */ #if 0 _get_cpsr: /* GDB will query for CPSR value specifically */ mov r1, #REG_CPSR /* Output User CPSR Value last */ bl _dbg_outputOneRegValue /* update output buffer */ #endif _asciiz r0, r1 bl dbg__putDebugMsg /* Send response to the GDB server */ ldmfd sp!, {pc} /* _dbg_setOneRegValue * Given Register Enum (0-F: R0-R15, 0x19: CPSR, OtherVal: dummy), output hex char to buffer * On entry: * r0: parameter buffer pointer * r1: register enum (0-F, 0x19) * On exit: * r0: (Updated) Address of parameter in buffer * r1, r2, r3: destroyed */ _dbg_setOneRegValue: stmfd sp!, {lr} cmp r1, #REG_PC addls r2, r1, #DBGSTACK_USERREG_INDEX /* Convert register enum to Debug Stack index */ bls _store_RegVal cmp r1, #REG_CPSR moveq r2, #DBGSTACK_USERCPSR_INDEX /* convert register enum to Debug Stack index */ beq _store_RegVal bhi _exit_dbg_setOneRegValue /* No match (reg enum > REG_CPSR), skip */ #if 0 cmp r1, #REG_FPSCR bne _exit_dbg_setOneRegValue /* No match, skip */ /* FIXME: If we get SetAllRegs with FP reg values, this will not skip pass the FP regs! */ #endif _set_dummy_regval: /* Set dummy FPSCR value (ignored) */ add r1, r0, #CMD_REG_REGPARAMLEN /* Just increment the pointer */ b _done_store_RegVal _store_RegVal: #ifdef __BIG_ENDIAN__ bl ascii2word_be #else bl ascii2word_le #endif /* R0: value, R1: pointer to next char in buffer */ _setdbgregisterfromindex r2, r0, r3 /* Set Register contents in R0, using index in R2, and scratch register R3 */ _done_store_RegVal: mov r0, r1 /* Copy buffer pointer to next parameter to R0 for return value */ _exit_dbg_setOneRegValue: ldmfd sp!, {pc} /* _dbg__cmd_SetOneReg * Set One Register Value Command Handler * Valid command parameter x is from '0' to 'F' for User Mode Registers R0-R15, * '18' for FPSCR (dummy), and '19' for CPSR * On entry: * r0: parameter buffer pointer (contents after '$' and '') * x=rrrr * On exit: * r0, r1, r2, r3, r4: destroyed * */ _dbg__cmd_SetOneReg: stmfd sp!, {lr} bl __dbg__cmdParamLen cmp r1, #CMD_REG_SETONE_MINPARAMLEN /* Check for correct length */ blo __dbg__procCmdParamError /* Unexpected input, report error */ cmp r1, #CMD_REG_SETONE_MAXPARAMLEN /* Check for correct length */ bhi __dbg__procCmdParamError /* Unexpected input, report error */ bl ascii2hex_varlen_be /* convert ASCII reg enum to Hex (in R0), R1 has address of next buffer char */ mov r4, r0 /* Keep enum in R4 */ _check_msgassignment r1 /* R1 points to next char in buffer */ bne __dbg__procCmdParamError /* Can't find '=' */ _dbg__proc_setRegister: mov r0, r1 /* move parameter buffer pointer to R0 */ mov r1, r4 /* and retrieve enum to R1 to call _dbg_setOneRegValue */ bl _dbg_setOneRegValue b __dbg__procCmdOk /* _dbg__cmd_SetAllReg * Set All Register Values Command Handler * On entry: * r0: parameter buffer pointer (contents after '$' and '') * rrrrRRRRrrrr... (17 registers) * On exit: * r0, r1, r2, r3, r4: destroyed * */ _dbg__cmd_SetAllRegs: /* Assumes that the registers are in the sequence R0, R1, ... R15, CPSR */ stmfd sp!, {lr} bl __dbg__cmdParamLen /* R0: pointer to parameters in buffer */ teq r1, #CMD_REG_SETALL_PARAMLEN /* Check for correct length */ bne __dbg__procCmdParamError /* Unexpected input, report error */ mov r4, #REG_R0 /* R4: register enum, starting with enum for R0 */ 1: mov r1, r4 /* Copy enum to R1; R0 already points to current parameter */ bl _dbg_setOneRegValue /* R0: next parameter address pointer */ add r4, r4, #1 /* increment index */ cmp r4, #REG_PC bls 1b _set_cpsr: #if 0 /* GDB was not happy when this was added */ /* Read dummy FPSCR value (ignored) */ #ifdef __BIG_ENDIAN__ bl ascii2word_be #else bl ascii2word_le #endif mov r0, r1 /* Copy buffer pointer to next parameter to R0 for return value */ #endif mov r1, #REG_CPSR /* Use CPSR enum */ bl _dbg_setOneRegValue /* R0: next parameter address pointer */ ldrb r0, [r0] teq r0, #0 /* Look for ASCIIZ character to terminate loop */ beq __dbg__procCmdOk bne __dbg__procCmdParamError /* Unexpected input, report error */ /* _dbg__nop * NOP Command Handler (placeholder) * On entry: * r0: parameter buffer (contents after '$' and '') * On exit: * r0, r1, r2, r3: destroyed */ _dbg__nop: stmfd sp!, {lr} b __dbg__procUnimplementedError /* _dbg__cmd_ReadMem * Read Memory Contents Command Handler * Output Buffer returns memory contents * On entry: * r0: parameter buffer pointer (contents after '$' and '') * AA..AA,LLLL * On exit: * r0, r1, r2, r3, r4, r5: destroyed */ _dbg__cmd_ReadMem: stmfd sp!, {lr} bl __dbg__cmdParamLen #if 0 teq r1, #CMD_MEM_READ_PARAMLEN /* Check for correct length */ bne __dbg__procCmdParamError /* Unexpected input, report error */ bl ascii2word_be /* convert ASCII address location to Hex (in R0), R1 has address of next buffer char */ #endif bl ascii2hex_varlen_be /* convert ASCII address to Hex (in R0), R1 has address of next buffer char */ mov r5, r0 /* Keep Address location in R5 */ _check_msgseparator r1 bne __dbg__procCmdParamError /* Can't find ',' */ mov r0, r1 /* move buffer pointer to R0 for subsequent processing */ bl ascii2hex_varlen_be /* convert ASCII length to Hex (in R0), R1 has address of next buffer char */ cmp r0, #CMD_MEM_MAXREADBYTES /* Don't overflow our buffer (2 x CMD_MEM_MAXREADBYTES) */ bhi __dbg__procCmdReturnOutputLengthError /* Requested Length greater than buffer size, return error */ mov r4, r0 /* Keep numbytes in R4 */ /* FIXME: Should validate the address? */ _dbg_outputMsgValidResponse /* R0: address of output message buffer data pointer (after response prefix) */ 1: ldrb r1, [r5], #1 bl byte2ascii /* update output buffer */ subs r4, r4, #1 bne 1b _asciiz r0, r1 bl dbg__putDebugMsg /* Send response to the GDB server */ ldmfd sp!, {pc} /* _dbg__cmd_WriteMem * Write Memory Contents Command Handler * On entry: * r0: parameter buffer pointer (contents after '$' and '') * AA..AA,LLLL::bb..bb * On exit: * r0, r1, r2, r3, r4: destroyed */ _dbg__cmd_WriteMem: stmfd sp!, {lr} bl __dbg__cmdParamLen #if 0 cmp r1, #CMD_MEM_WRITE_MINPARAMLEN /* Check for correct (minimum) length */ blo __dbg__procCmdParamError /* Unexpected input, report error */ sub r4, r1, #CMD_MEM_WRITE_MINPARAMLEN /* R4: Number of ASCII Hex chars for byte writes */ bl ascii2word_be /* convert ASCII address location to Hex (in R0), R1 has address of next buffer char */ #endif bl ascii2hex_varlen_be /* convert ASCII address to Hex (in R0), R1 has address of next buffer char */ mov r3, r0 /* Keep Address location in R3 */ _check_msgseparator r1 bne __dbg__procCmdParamError /* Can't find ',' */ mov r0, r1 /* move buffer pointer to R0 for subsequent processing */ bl ascii2hex_varlen_be /* convert ASCII length to Hex (in R0), R1 has address of next buffer char */ cmp r0, r4, asr #1 /* is Number of bytes to write == (number of ASCII Hex Chars / 2)? */ bne __dbg__procCmdParamError /* Number of bytes does not match argument length */ cmp r0, #CMD_MEM_MAXWRITEBYTES /* Don't overflow our buffer (2 x CMD_MEM_MAXWRITEBYTES) */ bhi __dbg__procCmdReturnInputLengthError /* Requested Length greater than buffer size, return error */ mov r4, r0 /* Keep numbytes in R4 */ /* FIXME: Should validate the address? */ _check_msgargument r1 bne __dbg__procCmdParamError /* Can't find ':' */ 1: mov r0, r1 bl ascii2byte /* convert ASCII Hex value into byte value */ strb r0, [r3], #1 /* Store into memory location */ subs r4, r4, #1 bne 1b b __dbg__procCmdOk /* _dbg__cmd_Detach * Detach User Program Execution Command Handler * Treat this as being equivalent to 'Continue' without any arguments * * On entry: * r0: parameter buffer pointer (contents after '$' and '') * (No Parameters) * On exit: * r0-r7: destroyed * Note: This routine does not return to caller. Instead it switches * operating mode to UNDEF and returns to previously active program */ _dbg__cmd_Detach: stmfd sp!, {lr} /* In case unexpected parameters were received */ bl __dbg__cmdParamLen teq r1, #CMD_DETACH_PARAMLEN /* Check for correct length */ bne __dbg__procCmdParamError /* Unexpected input, report error */ ldmfd sp!, {lr} /* Cleanup stack, since we won't return to the Debugger Run Loop */ _dbg_setstate DBG_INIT /* Reset the Debug State */ bl __dbg__procOkOnly /* send OK to keep GDB server happy */ b _dbg__cont_check_breakpoint_type /* Continue from current PC */ /* _dbg__cmd_Continue * Continue User Program Execution Command Handler * Setup breakpoints before resuming execution of program. * * If Address is specified, update the next instruction address to specified address * * If this is a Normal Breakpoint, then we resume from current (Breakpoint) exception address * Else (it is a Manual Breakpoint or Address Specified) * We need to resume from the next instruction address * On entry: * r0: parameter buffer pointer (contents after '$' and '') * Optional: AA..AA * On exit: * r0-r7: destroyed * Note: This routine does not return to caller. Instead it switches * operating mode to UNDEF and returns to previously active program */ _dbg__cmd_Continue: /* Don't put anything on the stack, we won't return to the Debugger Run Loop */ bl __dbg__cmdParamLen cmp r1, #CMD_CONTINUE_MINPARAMLEN /* Check for correct parameter length */ bne _dbg__cont_fromAddr /* Address is specified */ bl __dbg__procAckOnly /* send Ack to keep GDB server happy */ b _dbg__cont_check_breakpoint_type /* Continue from current PC */ _dbg__cont_fromAddr: bl ascii2hex_varlen_be /* convert ASCII address to Hex (in R0), R1 has address of next buffer char */ /* Continue from Specified Address */ _setdbgregister DBGSTACK_NEXTINSTR_INDEX, r0, r1 /* Set Next Instruction Pointer for Resume using contents of R0, and scratch register R1 */ bl __dbg__procAckOnly /* send Ack to keep GDB server happy */ b _dbg__cont_is_manual_bkpt_or_address_specified _dbg__cont_check_breakpoint_type: _dbg_get_bkpt_type r0 teq r0, #DBG_MANUAL_BKPT_ARM beq _dbg__cont_is_manual_bkpt_or_address_specified teq r0, #DBG_MANUAL_BKPT_THUMB beq _dbg__cont_is_manual_bkpt_or_address_specified _dbg__cont_is_normal_breakpoint: _getdbgregister DBGSTACK_USERPC_INDEX, r0 /* Retrieve Aborted Instruction PC from the Debug Stack into R0 */ _setdbgregister DBGSTACK_NEXTINSTR_INDEX, r0, r1 /* Set Next Instruction Pointer for Resume using contents of R0, and scratch register R1 */ /* GDB knows to Step from a breakpointed instruction before continuing when * Continue is issued, so it is safe to activate all defined breakpoints and continue. */ _dbg__cont_is_manual_bkpt_or_address_specified: bl _dbg__activate_breakpoints /* Restore exisiting breakpoints */ b _dbg__switch2undefmode /* _dbg__cmd_Step * Step User Program Execution Command Handler * Setup breakpoints before resuming execution of program. * * If Address is specified, update the next instruction address to specified address * * If this is a Normal Breakpoint, then we need to install a Step Breakpoint at next instruction address * and resume from current (Breakpoint) exception address * Else (it is a Manual Breakpoint or Address specified) * We need to install a Step Breakpoint at the following instruction address (after the next instruction address) * and resume from the next instruction address * On entry: * r0: parameter buffer pointer (contents after '$' and '') * Optional: AA..AA * On exit: * r0-r7: destroyed * Note: This routine does not return to caller. Instead it switches * operating mode to UNDEF and returns to previously active program */ _dbg__cmd_Step: /* Don't put anything on the stack, we won't return to the Debugger Run Loop */ bl __dbg__cmdParamLen cmp r1, #CMD_STEP_MINPARAMLEN /* Check for correct parameter length */ beq _dbg__step_check_breakpoint_type /* Step from current PC */ _dbg__step_fromAddr: bl ascii2hex_varlen_be /* convert ASCII address to Hex (in R0), R1 has address of next buffer char */ /* Step from Specified Address */ _setdbgregister DBGSTACK_NEXTINSTR_INDEX, r0, r1 /* Set Next Instruction Pointer for Resume using contents of R0, and scratch register R1 */ b _dbg__step_is_manual_bkpt_or_address_specified _dbg__step_check_breakpoint_type: _dbg_get_bkpt_type r0 teq r0, #DBG_MANUAL_BKPT_ARM beq _dbg__step_is_manual_bkpt teq r0, #DBG_MANUAL_BKPT_THUMB beq _dbg__step_is_manual_bkpt _dbg__step_is_normal_breakpoint: _getdbgregister DBGSTACK_USERPC_INDEX, r0 /* Retrieve Aborted Instruction PC from the Debug Stack into R0 */ _setdbgregister DBGSTACK_NEXTINSTR_INDEX, r0, r1 /* Set Next Instruction Pointer for Resume usinh contents in R0, and scratch register R1 */ b _dbg__step_is_manual_bkpt_or_address_specified _dbg__step_is_manual_bkpt: _getdbgregister DBGSTACK_NEXTINSTR_INDEX, r0 /* Retrieve Next Instruction Pointer for Resume into R1 */ /* b _dbg__step_is_manual_bkpt_or_address_specified */ _dbg__step_is_manual_bkpt_or_address_specified: bl dbg_following_instruction_addr /* following instruction address returned in r1 */ bl dbg__install_singlestep /* Setup Single Step, next instruction address returned in r1 */ bl dbg__activate_singlestep #if 0 /* Disable ACK transmit, let the next Breakpoint generate the Signal Response */ bl __dbg__procAckOnly /* send Ack to keep GDB server happy */ #endif b _dbg__switch2undefmode /* _dbg__cmd_Kill * Kill User Program Execution Command Handler * Kill Program, this is accomplished by rebooting the Brick * * On entry: * r0: parameter buffer pointer (contents after '$' and '') * (No Parameters) * On exit: * r0-r7: destroyed * Note: This routine does not return to caller. Instead it calls * the relevant system routine to reboot the Brick */ _dbg__cmd_Kill: stmfd sp!, {lr} /* In case unexpected parameters were received */ bl __dbg__cmdParamLen teq r1, #CMD_KILL_PARAMLEN /* Check for correct length */ bne __dbg__procCmdParamError /* Unexpected input, report error */ bl __dbg__procAckOnly /* send Ack to keep GDB server happy */ b dbg__reboot /* Goodbye.... */ /* _dbg__proc_brkpt_params * Process Breakpoint Parameters * On entry: * r0: parameter buffer pointer (contents after '$' and '') * t,AA..AA,k * On exit: * r0: non-zero = breakpoint address; 0 = parameter error * r1: destroyed * r2: destroyed * r3: destroyed */ _dbg__proc_brkpt_params: /* FIXME: Add support for watchpoints */ stmfd sp!, {lr} mov r3, r0 /* Keep parameter buffer address in R3 */ ldrb r0, [r3], #1 /* get breakpoint type t */ bl char2hex cmp r0, #CMD_BKPT_TYPE_BREAK_MEMORY bne _dbg__proc_brkpt_params_error /* We only support memory breakpoints for now */ _check_msgseparator r3 bne _dbg__proc_brkpt_params_error /* Something wrong with the parameters */ mov r0, r3 /* Check Address */ bl ascii2hex_varlen_be /* convert ASCII address to Hex (in R0), R1 has address of next buffer char */ mov r3, r0 /* Keep breakpoint address in R3 */ _check_msgseparator r1 bne _dbg__proc_brkpt_params_error /* Something wrong with the parameters */ ldrb r0, [r1], #1 /* get breakpoint kind k */ bl char2hex cmp r0, #CMD_BKPT_KIND_THUMB orreq r3, r3, #1 /* Mark Thumb breakpoints */ beq _exit_dbg__proc_brkpt_params cmp r0, #CMD_BKPT_KIND_ARM beq _exit_dbg__proc_brkpt_params /* ARM breakpoint */ _dbg__proc_brkpt_params_error: mov r3, #0 /* Unrecognized breakpoint type */ _exit_dbg__proc_brkpt_params: mov r0, r3 /* return breakpoint address */ ldmfd sp!, {pc} /* _dbg__cmd_InsertBreakpoint * Add Breakpoint * On entry: * r0: parameter buffer pointer (contents after '$' and '') * t,AA..AA,k * On exit: * r0, r1, r2, r3: destroyed */ _dbg__cmd_InsertBreakpoint: stmfd sp!, {lr} bl __dbg__cmdParamLen teq r1, #CMD_BKPT_INSERT_MINPARAMLEN /* Check for correct length */ blo __dbg__procCmdParamError /* Unexpected input, report error */ bl _dbg__proc_brkpt_params /* R0: Breakpoint Address */ teq r0, #0 beq __dbg__procBreakpointAddrError /* Thumb2 instructions, or unknown kind */ mov r3, r0 /* Keep breakpoint address in R3 */ mov r0, #0 /* Empty Breakpoint entry */ bl _dbg_find_breakpoint_slot /* Look for an available breakpoint slot, return index in R0 */ cmp r0, #CMD_BKPT_NOTFOUND beq __dbg__procBreakpointAddrError /* No empty slot! */ mov r1, r3 /* Move breakpoint address to R1 */ bl _dbg__install_one_breakpoint /* r0: index, r1: instruction address */ b __dbg__procCmdOk /* _dbg__cmd_RemoveBreakpoint * Remove Breakpoint * On entry: * r0: parameter buffer pointer (contents after '$' and '') * t,AA..AA,k * On exit: * r0, r1, r2, r3: destroyed */ _dbg__cmd_RemoveBreakpoint: stmfd sp!, {lr} bl __dbg__cmdParamLen teq r1, #CMD_BKPT_REMOVE_MINPARAMLEN /* Check for correct length */ blo __dbg__procCmdParamError /* Unexpected input, report error */ bl _dbg__proc_brkpt_params /* R0: Breakpoint Address */ teq r0, #0 beq __dbg__procBreakpointAddrError /* Thumb2 instructions, or unknown kind */ bl _dbg_find_breakpoint_slot /* Look for matching breakpoint slot, return index in R0 */ cmp r0, #CMD_BKPT_NOTFOUND beq __dbg__procBreakpointAddrError /* Specified Breakpoint not found! */ _index2bkptindex_addr r0, r1 /* Calculate Breakpoint Entry Address */ mov r0, r1 /* Move it to R0 for subroutine call */ bl _dbg__clear_one_breakpoint /* R0: address of breakpoint to clear */ b __dbg__procCmdOk /**************************************************************************** * * Breakpoint Manipulation Routines * ****************************************************************************/ /* _dbg_find_breakpoint_slot * Find the matching Breakpoint Slot. * This is both used to find empty slots (pass R0=0x0000) or * occupied slots (pass R0=) * * On Entry: * R0: Breakpoint Address * On Exit: * R0: Matching Index (-1: not found) * * NOTE: This routine performs exact match, i.e., breakpoint address MUST be configured * for ARM or Thumb (bit 0 clear/set) as appropriate */ _dbg_find_breakpoint_slot: stmfd sp!, {r1,r2,r3, lr} mov r1, #1 /* Only consider Breakpoints 1-7 */ ldr r3, =__breakpoints_num__ 1: _index2bkptindex_addr r1, r2 /* Calculate Breakpoint Entry Address */ ldr r2, [r2] /* Get actual breakpoint entry (instruction address) */ cmp r0, r2 beq _found_breakpoint_slot add r1, r1, #1 /* no match, check next */ cmp r1, r3 blo 1b /* continue checking only if we don't exceed __breakpoints_num__ */ _notfound_breakpoint_slot: mov r1, #CMD_BKPT_NOTFOUND _found_breakpoint_slot: mov r0, r1 /* Return value in R0 */ ldmfd sp!, {r1,r2,r3, pc} /* _dbg__clear_singlestep * Clear the Single Step Breakpoint */ _dbg__clear_singlestep: ldr r0, =__breakpoints_start__ /* Single Step Breakpoint is at the beginning of the Breakpoint State Struct */ /* b _dbg__clear_one_breakpoint */ /* _dbg__clear_one_breakpoint * On entry, R0 contains the Breakpoint State slot address to be cleared * */ _dbg__clear_one_breakpoint: mov r1, #0 mov r2, #0 stmea r0!, {r1, r2} /* clear Breakpoint state */ bx lr /* _dbg__clear_breakpoints * Routine iterates through the array of breakpoints (incl single step breakpoint) and clears the breakpoint */ _dbg__clear_breakpoints: stmfd sp!, {lr} ldr r0, =__breakpoints_start__ /* Single Step Breakpoint is at the beginning of the Breakpoint State Struct */ ldr r3, =__breakpoints_end__ /* start from top of the table */ 3: bl _dbg__clear_one_breakpoint cmp r0, r3 blo 3b ldmfd sp!, {pc} .global dbg__install_singlestep /* dbg__install_singlestep * Install the Single Step Breakpoint * * On entry: * R1: Instruction Address (31 bits, b0 = THUMB flag) * On exit: * R0: Breakpoint index (preserved) * R1: Instruction Address (preserved) * R2: Breakpoint Instruction * R3: Breakpoint Entry address */ dbg__install_singlestep: mov r0, #0 /* b _dbg__install_one_breakpoint */ /* _dbg__install_one_breakpoint * Install breakpoint entry into Breakpoint State Table * * On entry: * R0: Breakpoint index (assumed valid) * R1: Instruction Address (31 bits, b0 = THUMB flag) * On exit: * R0: Breakpoint index (preserved) * R1: Instruction Address (preserved) * R2: Breakpoint Instruction * R3: Breakpoint Entry address */ _dbg__install_one_breakpoint: /* Check for Thumb bit */ tst r1, #BKPT_STATE_THUMB_FLAG /* 1: Thumb instruction */ /* Assume that the address entry is valid, otherwise we should sanitize it (mask out b1) */ bic r2, r1, #BKPT_STATE_THUMB_FLAG /* R2: Instruction Address; clear Thumb Flag for accessing Memory */ ldreq r2, [r2] /* if 0: load ARM instruction from address location */ ldrneh r2, [r2] /* else load Thumb instruction */ _index2bkptindex_addr r0, r3 /* Calculate Breakpoint Entry Address */ stm r3, {r1, r2} bx lr /* _dbg__restore_singlestep * Restores the contents of the single step breakpoint to memory * * On entry: * None * On exit: * R0-R2: Destroyed */ _dbg__restore_singlestep: mov r0, #0 /* single step breakpoint index */ _index2bkptindex_addr r0, r1 /* Calculate Single Step Breakpoint Entry Address */ ldm r1, {r1, r2} /* r1: Breakpoint Address, r2: Breakpoint Instruction */ teq r1, #0 bxeq lr /* Exit if not active */ /* b _dbg__restore_one_breakpoint */ /* _dbg__restore_one_breakpoint * Restores the contents to memory for one breakpoint * * On entry: * R0: Breakpoint index (assumed valid) [not used -- can be used for validating BKPT] * R1: Breakpoint Address (assumed valid) * R2: Breakpoint Instruction (assumed valid) * On exit: * R0: Breakpoint index (preserved) * R1: B0 cleared if Thumb Instruction Address * R2: Breakpoint Instruction (preserved) */ _dbg__restore_one_breakpoint: /* Check for Thumb bit */ tst r1, #BKPT_STATE_THUMB_FLAG /* 1: Thumb instruction */ /* Assume that the address entry is valid, otherwise we should sanitize it (mask out b1) */ streq r2, [r1] /* if 0: restore ARM instruction to address location */ bicne r1, #BKPT_STATE_THUMB_FLAG /* else, clear Thumb Flag */ strneh r2, [r1] /* store Thumb instruction */ bx lr /* _dbg__restore_breakpoints * Routine iterates through the array of breakpoints (incl single step breakpoint) and restores the contents to memory * Only Active breakpoints (i.e., Non-zero Address) are processed. * * On entry: * None * On exit: * R0-R6: Destroyed */ _dbg__restore_breakpoints: stmfd sp!, {lr} ldr r6, =_dbg__restore_one_breakpoint b __dbg__iterate_breakpoint_array .global dbg__activate_singlestep /* dbg__activate_singlestep * Activate the single step breakpoint to memory * * On entry: * None * On exit: * R0-R3: Destroyed */ dbg__activate_singlestep: mov r0, #0 /* single step breakpoint index */ _index2bkptindex_addr r0, r1 /* Calculate Single Step Breakpoint Entry Address */ ldm r1, {r1, r2} /* r1: Breakpoint Address, r2: Breakpoint Instruction */ teq r1, #0 bxeq lr /* Exit if not active */ /* b _dbg__activate_one_breakpoint */ /* _dbg__activate_one_breakpoint * Activate one breakpoint to memory * * On entry: * R0: Breakpoint index (assumed valid) * R1: Breakpoint Address (assumed valid) * R2: Breakpoint Instruction (assumed valid) * On exit: * R0: Breakpoint index (preserved) * R1-R3: Destroyed */ _dbg__activate_one_breakpoint: /* Check for Thumb bit */ tst r1, #BKPT_STATE_THUMB_FLAG /* 1: Thumb instruction */ bne _nx_is_thumb_bp _nx_is_arm_bp: /* Assume that the address entry is valid, otherwise we should sanitize it (mask out b1) */ ldr r3, [r1] /* if 0: load ARM instruction from address location */ teq r2, r3 /* check that the two instructions are identical */ bne _dbg__breakpoint_invalid_arm ldr r2, =BKPT32_INSTR /* ARM BKPT instruction */ orr r2, r2, r0 /* Merge Breakpoint index */ str r2, [r1] /* Store it into memory location */ _dbg__breakpoint_invalid_arm: bx lr _nx_is_thumb_bp: bic r1, #BKPT_STATE_THUMB_FLAG /* else, clear Thumb Flag */ ldrh r3, [r1] /* load Thumb instruction from address location */ teq r2, r3 /* check that the two instructions are identical */ bne _dbg__breakpoint_invalid_thumb ldr r2, =BKPT16_INSTR /* Thumb BKPT instruction */ orr r2, r2, r0 /* Merge Breakpoint index */ strh r2, [r1] /* Store it into memory location */ _dbg__breakpoint_invalid_thumb: bx lr /* _dbg__activate_breakpoints * Routine iterates through the array of breakpoints (incl single step breakpoint) and activates them * Only Active breakpoints (i.e., Non-zero Address) are processed. * * On entry: * None * On exit: * R0-R6: Destroyed */ _dbg__activate_breakpoints: stmfd sp!, {lr} ldr r6, =_dbg__activate_one_breakpoint b __dbg__iterate_breakpoint_array /* __dbg__iterate_breakpoint_array * WARNING: DO NOT CALL THIS ROUTINE DIRECTLY. * Internal Routine, assumes that lr has been push to stack * * Common routine to iterate through the array of breakpoints (incl single step breakpoint) * Only Active breakpoints (i.e., Non-zero Address entries) are processed. * * On Entry: * R0: Breakpoint index * R1: Breakpoint Address * R2: Breakpoint Instruction * R6: Handler Routine * On exit: * R0-R5: Destroyed * R6: Handler routine (preserved) * */ __dbg__iterate_breakpoint_array: ldr r5, =__breakpoints_end__ /* start from top of the table (Assume __breakpoints_end__ > __breakpoints_start__) */ ldr r4, =__breakpoints_start__ /* end address check */ ldr r0, =__breakpoints_num__ /* Number of Breakpoints (incl Single Step) (Assume Non-Zero) */ 4: sub r0, r0, #1 /* Decrement breakpoint index in r0 */ ldmea r5!, {r1, r2} /* r1: Breakpoint Address, r2: Breakpoint Instruction */ teq r1, #0 /* Is it active? */ movne lr, pc bxne r6 /* active entry */ cmp r5, r4 bhi 4b /* if (pointer > start of Breakpoint Table address), get next slot */ ldmfd sp!, {pc}