WEBVTT 00:00.470 --> 00:01.580 Hello, my name is Stefan. 00:01.580 --> 00:07.780 And in this lecture we are going to develop our project calculator project further here. 00:07.790 --> 00:14.270 Now, as I always do, we will I will explain the code while I'm writing it. 00:14.270 --> 00:17.570 And also, uh, when I'm done. 00:17.570 --> 00:27.290 So now we will need to develop our BBS section here, uh, which we will just uh, define two variables. 00:27.290 --> 00:35.720 So section BBS, result result I rescue here. 00:35.720 --> 00:42.860 One result or modulo here is rescue one as well. 00:43.040 --> 00:49.520 And here we will define text section where we will our code will be written. 00:49.520 --> 00:54.710 We will define global main define the main function. 00:54.890 --> 00:59.300 We will here write push RVP move. 01:01.540 --> 01:03.640 RWP rsp. 01:03.670 --> 01:04.930 You already know what that means. 01:04.930 --> 01:06.130 But I will also. 01:06.340 --> 01:08.080 I will explain it again. 01:08.500 --> 01:17.290 And what we're going to do is we will display the numbers here and we will write five instructions, 01:17.290 --> 01:20.830 move the i fmt. 01:22.340 --> 01:24.110 We need this tabs. 01:24.990 --> 01:30.300 So basically we are loading the address of format string to RDR. 01:30.330 --> 01:33.180 Remember this format string is the number here. 01:34.420 --> 01:37.090 Fmt move here. 01:37.480 --> 01:38.290 RSI. 01:40.100 --> 01:42.350 This is number one. 01:42.380 --> 01:49.510 This is the this is for loading the value of number one into RSI. 01:50.670 --> 01:50.850 Here. 01:50.880 --> 01:56.190 Number one is 128 and number two is 19. 01:57.520 --> 02:01.450 And here we will do the same for number. 02:03.230 --> 02:03.950 To. 02:03.980 --> 02:05.360 So move. 02:06.380 --> 02:07.640 Are the eggs. 02:10.280 --> 02:14.390 Number two and move. 02:15.250 --> 02:16.000 Racks. 02:20.410 --> 02:21.040 Zero. 02:21.610 --> 02:26.170 And after that we will call a printf to display the formatted message call. 02:26.290 --> 02:27.370 Printf. 02:28.570 --> 02:32.470 And after that we will need to write the adding here. 02:33.250 --> 02:36.280 So move racks. 02:40.220 --> 02:41.310 Number of. 02:44.400 --> 02:45.510 Number one. 02:47.590 --> 02:48.190 At. 02:48.920 --> 02:49.820 Racks. 02:51.710 --> 02:52.910 Number two. 02:54.040 --> 03:00.100 Here in this here we are loading the value of number one into racks and. 03:01.380 --> 03:06.360 We are doing the same for adding the value of number two to racks. 03:06.360 --> 03:14.250 But here we are loading and here in this here we are adding here, which you will see the difference 03:14.250 --> 03:16.710 right now and result. 03:16.740 --> 03:24.090 We will store the result in this result I reserve so. 03:26.640 --> 03:27.270 Result. 03:27.310 --> 03:28.950 I hear. 03:30.290 --> 03:31.040 Tracks. 03:33.980 --> 03:36.380 And after that, we need to. 03:37.910 --> 03:40.610 We need to display the result as well again. 03:41.180 --> 03:44.880 So display the result. 03:44.900 --> 03:46.220 So move. 03:46.260 --> 03:47.000 Ready? 03:48.940 --> 03:54.790 Fmt fmt integer, which we define somewhere here. 03:57.510 --> 03:57.870 So. 03:59.910 --> 04:01.200 Empty end. 04:02.220 --> 04:08.220 Now what we're going to what we are doing here is we are loading and loading the address of format string 04:08.250 --> 04:12.120 to RTI and MOV RSI. 04:13.390 --> 04:13.960 Some. 04:14.890 --> 04:15.940 Am I here? 04:16.150 --> 04:16.840 This is the. 04:16.840 --> 04:19.660 This is for loading the address of message to RSI. 04:20.200 --> 04:22.690 MOV rdx. 04:26.540 --> 04:29.060 And with this we will. 04:31.410 --> 04:32.250 Actually, yeah. 04:32.760 --> 04:42.540 Uh, uh, with RDX, we will need to load the value of result I result here uh, two, which is. 04:43.110 --> 04:45.450 Or we define it as a reserve. 04:47.130 --> 04:48.420 Who are the. 04:52.720 --> 04:54.130 And after that move. 04:55.060 --> 04:56.100 RDX. 04:57.420 --> 04:58.900 Or racks. 04:58.920 --> 04:59.700 Racks. 05:01.170 --> 05:01.770 Zero. 05:01.800 --> 05:08.490 With this, we are clearing the racks register, which is basically returning the value and after that 05:08.490 --> 05:11.030 we will call them printf. 05:12.200 --> 05:14.900 Which is calling primitive to display the formatted message. 05:21.530 --> 05:22.030 Printf? 05:22.340 --> 05:23.000 Yeah. 05:23.360 --> 05:28.490 And after that, we will need to create our subtracting here. 05:28.820 --> 05:33.220 And after that I will begin to explain these codes. 05:33.230 --> 05:33.710 So. 05:39.580 --> 05:44.560 Acting and move racks. 05:48.170 --> 05:49.240 Number one. 05:49.250 --> 05:53.810 Here we are loading the value of number one into racks sub. 05:55.500 --> 05:56.220 Racks. 05:58.800 --> 06:00.180 Number two. 06:01.470 --> 06:02.160 Move. 06:05.510 --> 06:06.830 Of result. 06:10.270 --> 06:10.860 Rags. 06:10.930 --> 06:12.460 Here we are, storing the value. 06:12.490 --> 06:15.320 Storing the result in a result. 06:15.340 --> 06:16.320 Result I. 06:16.330 --> 06:17.410 And here we are. 06:17.410 --> 06:18.060 Subtracting. 06:18.160 --> 06:22.270 Subtracting the value of number two from rags. 06:23.020 --> 06:27.700 And now we will need to display the result. 06:27.910 --> 06:30.820 Displaying the result. 06:32.240 --> 06:33.650 And here. 06:34.980 --> 06:35.220 That's. 06:36.590 --> 06:42.860 So here what we're going to do is we will load the address of, uh, format string to RTI. 06:43.700 --> 06:44.900 RTI. 06:49.640 --> 06:53.960 And FM to integer move. 06:54.700 --> 06:55.770 RSI. 06:57.820 --> 07:00.730 If you are here we are loading address of message to RSI. 07:01.240 --> 07:02.080 Move. 07:02.910 --> 07:03.450 Are the. 07:04.880 --> 07:07.400 This is fall result I. 07:09.240 --> 07:18.240 They are loading the value of result I to RDX and now we will move our r r a x. 07:18.600 --> 07:25.140 Here we are clearing the x register, returning the value again, and we will call the print. 07:25.590 --> 07:27.360 Our code is not yet done. 07:27.360 --> 07:31.560 We need to add another mathematical arithmetics as well. 07:31.560 --> 07:35.100 But here for this lecture, I will explain this. 07:35.130 --> 07:38.400 So, uh, here. 07:39.990 --> 07:44.520 At first you remember we had this push and move. 07:44.520 --> 07:45.480 RWP rsp. 07:46.650 --> 07:49.230 But we will start from here firstly. 07:49.230 --> 07:57.210 So with this here move ah, the I fmt we are moving the memory address of the format string fmt into 07:57.210 --> 08:02.940 RDA register and RDA will be used as the first argument for this printf function. 08:02.940 --> 08:08.400 And here we are moving the. 08:09.550 --> 08:15.640 Value stored at the memory location pointed to by number one into the RSI register. 08:15.640 --> 08:20.740 And this loads the value of the first number for displaying. 08:20.770 --> 08:27.850 And here we are moving the value stored at the memory location pointed to by number two into the RDX 08:27.880 --> 08:32.770 register, and this loads the value of second number for displaying as well. 08:32.770 --> 08:35.800 And here we are calling the um. 08:38.720 --> 08:40.820 And here we are calling the. 08:42.370 --> 08:50.470 Printf, which calls the string function to display the formatted message using the provided, um, 08:50.470 --> 08:57.070 argument like RTI, RSI and RDX here. 08:59.200 --> 09:02.750 And after that we have moved racks number one. 09:02.770 --> 09:04.180 This is for moved moves. 09:04.180 --> 09:09.580 The value stored at the memory location pointed to by number one into the racks register. 09:09.580 --> 09:10.740 And this. 09:10.750 --> 09:14.290 This loads the value of the first number for arithmetic operations. 09:14.290 --> 09:17.560 And here we are with this. 09:19.040 --> 09:20.130 Here we are telling. 09:20.180 --> 09:26.720 Telling the assembler to add the value stored at the memory location pointed to by number two to the 09:26.720 --> 09:28.340 value in Rax register. 09:28.340 --> 09:34.160 So this result the result is stored in Rax representing the sum of two numbers. 09:34.220 --> 09:39.680 And here we are storing the value in the rax register which is sum of the numbers. 09:40.070 --> 09:41.840 Sum of the numbers. 09:42.170 --> 09:49.960 Summary of the numbers into the memory location pointed to by result I here and we are. 09:51.360 --> 09:53.040 In display here. 09:53.070 --> 10:02.790 I move Fmt and RDL will be used as the first argument for the printf function and here RSI will be used 10:02.790 --> 10:05.580 as the second argument for the printf function here. 10:05.580 --> 10:07.800 And this loads the. 10:08.370 --> 10:14.040 This loads the result of the addition operation for displaying. 10:14.790 --> 10:22.200 So this clears the rax register, preparing it to be used as the return value for the printf function. 10:22.350 --> 10:28.950 And here we are calling the printf function to display the formatted message using the provided arguments, 10:28.950 --> 10:32.040 which is RDA, RSI and RDX. 10:32.040 --> 10:39.660 So this subsequent subtracting section follows a similar pattern with the sub instruction to subtract 10:39.660 --> 10:45.540 the second number from the first number and the same process for displaying the difference. 10:45.540 --> 10:46.830 And please. 10:50.770 --> 10:51.220 Here. 10:51.220 --> 10:57.280 Keep in mind that this printf is callable function from an external library. 10:58.270 --> 10:59.020 And. 11:00.110 --> 11:04.040 As you can see here, it's being used for output purposes. 11:05.170 --> 11:14.050 And as you can see here, we almost all fully completed we completed 50% of our program, which we will 11:14.050 --> 11:19.390 continue that in our lecture in in our next next lecture.