memory.c

PC连接ARM JTAG 接口工具的源代码

		 * Load R0 with the address to read.
		 * LDR R0, PC+xx = 0xE59F0000
		 */
		sc1->writein[0] = 0xE59F0000;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = addr;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* two NOPs are needed, and i don't know why? */
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		/* NOP with bit33 set HIGH */
		sc1->writein[0] = ARM_NOP;
		sc1->writein[1] = SYSTEM_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		/* LDMIA R0, {R1-R8}=1110 1000 1011 0000 0000 0001 1111 1110 */
		sc1->writein[0] = 0xE8B001FE;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* Write RESTART instruction into the TAP controller.
	 	 * When the state machine enters the Run-Test/Idle state,
		 * the ARM7TDMI core will revert back to system mode,
		 * and it will resynchronize clock to MCLK.
	 	 */
		jtag_write_ireg(JTAG_RESTART);
				
		/*
		 * Now, the ARM7TDMI core re-entered the debug state.
		 * Before the debug session continues, we must load the 
		 * TAP controller with the INTEST instruction. We can use
		 * the instruction "STM R9, {R1-R8}" running at debug-speed
		 * to read out the contents of registers R1-R8.
		 */
		jtag_select_scanchain(1);
		jtag_write_ireg(JTAG_INTEST);
		
		/* STM R0, {R1-R8} = 1110 1000 1000 0000 0000 0001 1111 1110 */
		sc1->writein[0] = 0xE88001FE;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		sc1->writein[0] = ARM_NOP; /* NOP */
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* in the next 8 cycles - read out R1-R8 */
		sc1->writein[0] = ARM_NOP; /* NOP */
		for (i = 0; i < 8; i++) {
			arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
			if (((lines*8) + i) < length)
				buf[(lines*8) + i] = sc1->readout[0];
		}
		
		lines++;
		addr += (4*8);
	}/* end of while(...) */

	/*
	 * Finally, clear breakpt ...
	 */
	arm7tdmi_ice_clear_breakpt();
	return 0;
} /* end of arm7tdmi_read32(...) */

int arm7tdmi_memory_write32(u32 *buf, u32 address, u32 length)
{
	int i, j, lines, remainder, retval;
	u32 addr = address;
	scan_chain_t *sc1 = &arm7tdmi_target.sc[1];
	
	if ((buf == NULL) || (length == 0))
		return -ERR_INVALID_PARAM;
	else if (target->status == TARGET_STATUS_RUNNING)
		return -ERR_TARGET_IS_RUNNING;
	else if (target->mode == TARGET_MODE_THUMB)
		return -ERR_TARGET_IN_THUMB_MODE;

	/* set a breakpoint */
	arm7tdmi_ice_set_breakpt();

	/* select scan chain 1, and use INTEST instruction */
	retval = jtag_select_scanchain(1);
	if (retval)
		return retval;
	retval = jtag_write_ireg(JTAG_INTEST);
	if (retval)
		return retval;

	addr &= 0xFFFFFFFC;  /* align address with word boundary */
	lines = length/8; /* 8 words per memory line */
	remainder = length%8;
	i = j =0;
	
	/* write one memory line each time */
	while (i < lines) {
		/*
		 * Load R0 with the address to write.
		 * LDR R0, PC+xx = 0xE59F0000
		 */
		sc1->writein[0] = 0xE59F0000;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = addr;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		/*
		 * Clear R1 - R8 to zero.
		 * If not doint this step, when i write even number into
		 * R1-R8, i always read back wrong result from R0-R8. Damn it.
		 * LDM R0, {R1-R8} = 1110 1000 1001 0000 0000 0001 1111 1110
		 */
		sc1->writein[0] = 0xE89001FE;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		/* in the next 8 cycles, we scan in the data to write */
		for (j = 0; j < 8; j++) {
			sc1->writein[0] = 0;
			arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		}

		/* the last cycle of LDM instruction */
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/*
		 * Load R1 - R8 with the data to write.
		 * LDM R0, {R1-R8} = 1110 1000 1001 0000 0000 0001 1111 1110
		 */
		sc1->writein[0] = 0xE89001FE;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		/* in the next 8 cycles, we scan in the data to write */
		for (j = 0; j < 8; j++) {
			sc1->writein[0] = buf[i*8+j];
			arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		}

		/* the last cycle of LDM instruction */
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* two NOPs are needed, and i don't know why? */
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* NOP with bit33 set HIGH */
		sc1->writein[0] = ARM_NOP;
		sc1->writein[1] = SYSTEM_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* STMIA R0, {R1-R8}=1110 1000 1000 0000 0000 0001 1111 1110 */
		sc1->writein[0] = 0xE88001FE;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* Write RESTART instruction into the TAP controller.
	 	 * When the state machine enters the Run-Test/Idle state,
		 * the ARM7TDMI core will revert back to system mode,
		 * and it will resynchronize clock to MCLK.
	 	 */
		jtag_write_ireg(JTAG_RESTART);

		/*
		 * Now, the ARM7TDMI core re-entered the debug state.
		 * Before the debug session continues, we must load the
		 * TAP controller with the INTEST instruction. We can use
		 * the instruction "STR R1, [R2]" running at debug-speed
		 * to read out the contents of registers R1-R8.
		 */
		jtag_select_scanchain(1);
		jtag_write_ireg(JTAG_INTEST);
		
		i++;
		addr += (4*8);
	} /* end of while(i < lines) */

	/* write the remaining words */
	i = 0;
	while (i < remainder) {
		/*
		 * Load R0 with the address to write.
		 * LDR R0, PC+xx = 0xE59F0000
		 */
		sc1->writein[0] = 0xE59F0000;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = addr;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		/*
		 * Clear R1 to zero. If not doing this step, when i write
		 * even number into R1, i always read back wrong result
		 * from R1. Damn it.
		 * LDR R1, [R1] = 1110 0101 1001 0001 0001 0000 0000 0000
		 */
		sc1->writein[0] = 0xE5911000;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = 0;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/*
		 * Load R1 with the data to write.
		 * LDR R1, [R1] = 1110 0101 1001 0001 0001 0000 0000 0000
		 */
		sc1->writein[0] = 0xE5911000;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = buf[lines*8 + i];
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		sc1->writein[0] = ARM_NOP;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		
		/* two NOPs are needed, and i don't know why? */
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* NOP with bit33 set HIGH */
		sc1->writein[0] = ARM_NOP;
		sc1->writein[1] = SYSTEM_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* STR R1, [R0] = 1110 0101 1000 0000 0001 0000 0000 0000 */
		sc1->writein[0] = 0xE5801000;
		sc1->writein[1] = DEBUG_SPEED;
		arm7tdmi_exec_instruction(sc1->writein, sc1->readout);

		/* Write RESTART instruction into the TAP controller.
	 	 * When the state machine enters the Run-Test/Idle state,
		 * the ARM7TDMI core will revert back to system mode,
		 * and it will resynchronize clock to MCLK.
	 	 */
		jtag_write_ireg(JTAG_RESTART);

		/*
		 * Now, the ARM7TDMI core re-entered the debug state.
		 * Before the debug session continues, we must load the
		 * TAP controller with the INTEST instruction. We can use
		 * the instruction "STR R1, [R2]" running at debug-speed to
		 * read out the contents of registers R1-R8.
		 */
		jtag_select_scanchain(1);
		jtag_write_ireg(JTAG_INTEST);
		
		i++;
		addr += 4;
	} /* end of while (i < remainder) */
	
	/*
	 * Finally, clear breakpt ...
	 */
	arm7tdmi_ice_clear_breakpt();
	return 0;
} /* end of arm7tdmi_write32(...) */