WEBVTT 00:01.060 --> 00:03.970 Hello, everyone, and welcome to today's video lecture. 00:03.970 --> 00:10.150 In this session, we are going to dive deep into an assembly code example that calculates the sum of 00:10.150 --> 00:13.000 numbers from zero to a given value. 00:13.030 --> 00:19.990 Using a loop construct, we will walk you through the code step by step, discussing how registers, 00:19.990 --> 00:25.840 loops and external functions work together to achieve the desired goal and result. 00:25.840 --> 00:29.500 And here in previous lecture, we just have some typo here. 00:29.500 --> 00:31.090 Let's quickly fix that. 00:31.120 --> 00:37.450 I fix that when I shared the previous lecture code in attachment sections, but I want to fix that. 00:38.430 --> 00:39.330 Uh, here. 00:39.360 --> 00:40.560 Uh, also here. 00:41.100 --> 00:47.060 And let's start by taking a look at the assembly code we will be exploring today. 00:47.070 --> 00:52.620 As you can see on the screen, we have a complete assembly program that calculates a sum of numbers 00:52.620 --> 00:54.120 using a loop. 00:54.120 --> 01:03.330 So the loop construct is quite interesting as it utilizes the RC x register. 01:04.410 --> 01:08.490 So the RC x register as a loop counter. 01:08.490 --> 01:12.960 So automatically decrementing with each iteration. 01:12.960 --> 01:18.630 So before we compile and run the code, let's break down the key components of the program. 01:18.630 --> 01:23.970 So we have a number variable that is initially set to five. 01:24.060 --> 01:27.330 This is the upper limit of our summation. 01:27.330 --> 01:35.040 We are using the printf function to display the calculated sum and the program initializes the loop 01:35.040 --> 01:47.530 counter rc x and an accumulator rax to perform the summation and the loop instruction decrements the 01:47.530 --> 01:53.170 loop counter and repeats the loop by the until the counter becomes zero. 01:53.170 --> 01:56.910 And now let's compile and run the code. 01:56.920 --> 01:59.860 Open your terminal here. 02:00.940 --> 02:03.190 Uh, go to the pod here. 02:04.280 --> 02:05.360 We should have instruction. 02:05.490 --> 02:07.850 Yes, the instruction flags. 02:07.850 --> 02:12.920 And here we have project as actually just let's remove the previous Mac file. 02:13.760 --> 02:18.530 And as you can see, we just only have this ESM file here. 02:18.530 --> 02:22.000 Let's read it Project Dot RSM. 02:22.010 --> 02:24.760 And as you can see, this is our codes that we wrote. 02:24.830 --> 02:26.410 We wrote in previous lecture. 02:26.420 --> 02:28.820 Now what we're going to do is we will create the. 02:30.270 --> 02:32.430 Make file so mousepad. 02:32.460 --> 02:33.780 Make file. 02:34.290 --> 02:42.750 And in this make file we will first add the command like make make file for the project dot ASM and 02:42.750 --> 02:43.350 project. 02:43.350 --> 02:45.930 Here we will make this to. 02:46.680 --> 02:51.930 Project all here and use, we will use the GCC output. 02:55.050 --> 02:56.270 All right from here. 02:57.000 --> 02:58.440 For project. 02:58.740 --> 03:00.710 We will use the GCC. 03:00.720 --> 03:01.530 GCC. 03:07.130 --> 03:11.640 Project project that will use no Pi. 03:13.170 --> 03:16.230 And project that all here. 03:17.940 --> 03:18.600 Roar. 03:20.190 --> 03:23.400 Project that ESM will use. 03:23.660 --> 03:24.990 NSM here. 03:25.830 --> 03:29.010 Elf 64 bit and some 64 bit here. 03:30.220 --> 03:35.700 F 64 G Uppercase L Uppercase F. 03:36.690 --> 03:38.450 Dwarf format. 03:39.690 --> 03:46.260 And project that ESM and we will also the listing here project that. 03:47.550 --> 03:49.110 Project list. 03:49.290 --> 03:51.070 And that's it. 03:51.090 --> 03:52.830 Let's close this now. 03:52.830 --> 03:55.820 Just write the make. 03:55.830 --> 03:57.930 And as you can see here, our program is. 03:58.890 --> 04:01.320 Compiled and linked and assembled here. 04:01.500 --> 04:05.100 And as you can see, we have this project, right? 04:05.250 --> 04:06.600 And now. 04:07.610 --> 04:13.700 Well, once compiled, we can execute the program by running the dot slash project. 04:13.850 --> 04:18.860 And as you can see, the sum from 0 to 5 is 15. 04:18.860 --> 04:21.980 So the that's it here. 04:22.100 --> 04:26.120 This is not so basic because we will also change the numbers. 04:26.120 --> 04:29.090 So now comes the exciting part. 04:29.120 --> 04:37.130 Now let's see how changing number value affects the program's execution and currently this number. 04:39.860 --> 04:40.180 Um. 04:40.340 --> 04:42.050 Yes, this number. 04:43.360 --> 04:44.770 Is set to five. 04:44.800 --> 04:48.730 Now let's change to the larger value. 04:49.120 --> 04:50.620 Uh, something, let's say. 04:51.640 --> 04:52.560 10 million. 04:52.570 --> 04:53.230 Ten. 04:55.540 --> 04:55.990 Here. 04:56.860 --> 04:57.700 And. 04:58.620 --> 05:02.250 Now let's make again and make. 05:06.790 --> 05:07.450 Project. 05:07.450 --> 05:13.100 And as you can see, the sound from 0 to 10 million is something like that, right? 05:13.120 --> 05:20.440 So now we save the saved the file compiled it, and now we can also observe the execution time. 05:20.440 --> 05:25.210 So before we run the program, let's discuss an experiment. 05:25.210 --> 05:33.010 So you can also use the time command in Linux to measure the execution time of the program. 05:33.160 --> 05:36.430 For instance, the Time project. 05:36.430 --> 05:43.780 And as you can see, execution time, the sum of sum from 0 to 1 million is something good. 05:44.110 --> 05:46.210 And here let's actually. 05:47.240 --> 05:50.600 This sum from 0 to 1 million, 1 million. 05:50.600 --> 05:53.180 But we also have this five, right? 05:53.180 --> 05:56.600 Let's actually check with this five again. 05:58.700 --> 06:03.320 As we opened the Oh no, we can't close this because the Sims is open here. 06:03.320 --> 06:07.430 So here, make again time. 06:09.330 --> 06:10.290 Project. 06:10.470 --> 06:11.940 We will note it down here. 06:12.630 --> 06:14.670 The psalm from here. 06:15.920 --> 06:23.750 As you can see here, the value gets bigger and our time is gets bigger, too. 06:26.080 --> 06:26.350 Here. 06:26.350 --> 06:28.540 Let's actually try 10 trillion. 06:35.540 --> 06:38.030 Now let's compile it again. 06:39.500 --> 06:40.220 Make. 06:41.620 --> 06:42.310 Time. 06:44.170 --> 06:45.130 Project. 06:46.490 --> 06:50.690 And as you can see here, let's give us some example here. 06:51.240 --> 06:53.150 Yeah, we are still waiting for it. 06:57.030 --> 07:03.750 And as you can see here, it's almost 20s to 12 seconds here, not 20. 07:04.020 --> 07:06.930 Now, we will this is for. 07:10.030 --> 07:10.600 This. 07:12.430 --> 07:12.910 Yes. 07:13.030 --> 07:15.310 So this is for 10 million. 07:15.780 --> 07:16.060 It did. 07:16.210 --> 07:22.150 It couldn't calculate because we reached the limits of our registers. 07:23.810 --> 07:24.680 Now. 07:25.540 --> 07:28.860 Let's even add six zeros. 07:28.870 --> 07:30.100 One, two, three. 07:30.310 --> 07:31.540 One, two, three. 07:31.720 --> 07:32.320 Here. 07:32.650 --> 07:34.480 Now let's test it with it. 07:36.360 --> 07:38.520 I'll ask Claire make. 07:39.930 --> 07:41.280 And time. 07:44.710 --> 07:45.550 Project. 07:58.000 --> 07:58.590 It might. 07:58.600 --> 08:01.780 I think it might take, like, more than. 08:02.910 --> 08:05.580 30s or 20s. 08:05.850 --> 08:06.630 Let's see. 08:09.630 --> 08:15.600 Also consider this like I'm running this operating system in my virtual machine. 08:17.160 --> 08:21.540 My CPU is Intel i7. 08:21.570 --> 08:23.820 The 10th generation. 08:25.470 --> 08:26.250 Let's see. 08:30.000 --> 08:32.390 Many times take here. 08:42.030 --> 08:42.310 Is it? 08:43.000 --> 08:43.570 No. 08:43.590 --> 08:45.840 So here, as you can see here, the. 08:47.950 --> 08:51.280 The sum from 0 to 5 is 15. 08:51.310 --> 08:55.990 The real is 0.003 seconds. 08:56.020 --> 09:07.500 The sum from 0 to 10 million is 0.0 16 seconds and the sum from 0 to 10. 09:07.960 --> 09:08.600 Yeah, it it. 09:08.770 --> 09:11.080 No, it was 10 billion, I think. 09:11.080 --> 09:11.590 Yeah. 09:14.070 --> 09:14.370 Yeah. 09:14.370 --> 09:14.850 Ten. 09:18.890 --> 09:28.070 Yeah, ten is some from uh, 0 to 10 billion is something like, uh, 11.944. 09:29.260 --> 09:31.240 Seconds now. 09:31.930 --> 09:33.550 We are still waiting for it. 09:34.540 --> 09:39.850 So our program will give us give us some output here. 09:39.970 --> 09:45.460 We just reached I think we reached the limits of our virtual machine processing unit. 09:45.460 --> 09:52.210 So this, um, Kali Linux here is installed on the virtual machine here. 09:52.210 --> 09:54.700 And as you can see here, it's 64 bit. 09:56.490 --> 09:56.970 Yeah. 09:57.060 --> 10:01.230 Love 11th generation Intel core i5. 10:02.500 --> 10:02.830 11. 10:02.830 --> 10:03.660 11. 10:03.670 --> 10:04.510 11. 10:04.510 --> 10:05.180 Four. 10:05.200 --> 10:05.640 No. 10:05.650 --> 10:06.070 11. 10:06.250 --> 10:08.350 I5 11 400. 10:08.400 --> 10:09.040 H. 10:10.450 --> 10:18.940 The GPU and memory is I gave eight memory from my 16 gigabyte ram. 10:21.630 --> 10:23.170 We are still waiting here. 10:23.620 --> 10:26.170 We can also check the processes here. 10:29.380 --> 10:37.750 And as you can see here, this project almost takes 25% of our CPU power. 10:37.900 --> 10:41.560 And here we are still waiting for it. 10:45.290 --> 10:52.460 Like were literally Chrome takes 0% and this takes 26% of our CPU power. 10:55.310 --> 10:56.120 The sexual check. 11:06.770 --> 11:13.430 Yeah, it might take, uh, the, uh, like days to compile complete this because my, uh, virtual 11:13.430 --> 11:15.590 machine is pretty slow in this case. 11:16.130 --> 11:22.360 Maybe we should try this on this native, uh, operating system here, but it doesn't matter. 11:22.370 --> 11:29.450 As you can see, by changing the number value, we can explore how the program behaves with different 11:29.450 --> 11:30.080 inputs. 11:30.080 --> 11:37.270 So this exercise showcases the power of assembly language in understanding low level computer operations. 11:37.280 --> 11:43.010 I hope you found this video lecture insightful and educational, and thank you for watching and feel 11:43.010 --> 11:43.370 free. 11:43.400 --> 11:51.620 Feel free to adjust the script as needed to match your style and preferences and good luck.