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RISCY BUSINESS»Episode Guide
Fun with Pointers & Printing
References ▼
SiFive Forums
Lots of Questions… (RISCY BUSINESS Day 21)
[1]0:45[2]3:27[3]8:46
[4]9:46
SiFive Forums
Arch Linux and the HiFive1
[5]45:20
SiFive Developers
SiFive HiFive1 Getting Started Guide
[6]54:18[7]57:51[8]59:43
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0:19Recap and set the stage for the day
0:19Recap and set the stage for the day
0:19Recap and set the stage for the day
0:45Consult DrewatSiFive's reply to the forum post1
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0:45Consult DrewatSiFive's reply to the forum post1
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0:45Consult DrewatSiFive's reply to the forum post1
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3:27Pointer assignment2
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3:27Pointer assignment2
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3:27Pointer assignment2
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8:46The Privileged spec is up in the air3
8:46The Privileged spec is up in the air3
8:46The Privileged spec is up in the air3
9:46printf4
9:46printf4
9:46printf4
12:20Run the hello world program to determine that we have a working printf()
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12:20Run the hello world program to determine that we have a working printf()
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12:20Run the hello world program to determine that we have a working printf()
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13:17hossein1387 Yeah, it works for me too. Magic
🗪
13:17hossein1387 Yeah, it works for me too. Magic
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13:17hossein1387 Yeah, it works for me too. Magic
🗪
13:33Fix up the *config_string assignment in print_instructions()
13:33Fix up the *config_string assignment in print_instructions()
13:33Fix up the *config_string assignment in print_instructions()
16:45Consult man 3 fflush and man 2 write
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16:45Consult man 3 fflush and man 2 write
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16:45Consult man 3 fflush and man 2 write
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18:43Comment out the fflush(), make clean, compile and upload
18:43Comment out the fflush(), make clean, compile and upload
18:43Comment out the fflush(), make clean, compile and upload
19:33Run our demo_gpio.c program and view the output
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19:33Run our demo_gpio.c program and view the output
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19:33Run our demo_gpio.c program and view the output
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20:38Change the printf() to print a string
20:38Change the printf() to print a string
20:38Change the printf() to print a string
24:29Run and see no output
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24:29Run and see no output
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24:29Run and see no output
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25:22Compare the difference between printf() in gpio_demo.c and in hello.c
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25:22Compare the difference between printf() in gpio_demo.c and in hello.c
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25:22Compare the difference between printf() in gpio_demo.c and in hello.c
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26:46Compare the Makefiles
26:46Compare the Makefiles
26:46Compare the Makefiles
27:26hossein1387 Can you try to clean your env? Because it works for me
🗪
27:26hossein1387 Can you try to clean your env? Because it works for me
🗪
27:26hossein1387 Can you try to clean your env? Because it works for me
🗪
27:50Run make software_clean and remove the fflush()
27:50Run make software_clean and remove the fflush()
27:50Run make software_clean and remove the fflush()
28:45Run the program to see inconsistent writing
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28:45Run the program to see inconsistent writing
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28:45Run the program to see inconsistent writing
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29:34hossein1387 I tried this in beginning of print_instructions(): unsigned char * ConfigString = (unsigned char*)*(volatile uint32_t *) 0x0000100C; printf("%s", ConfigString);
🗪
29:34hossein1387 I tried this in beginning of print_instructions(): unsigned char * ConfigString = (unsigned char*)*(volatile uint32_t *) 0x0000100C; printf("%s", ConfigString);
🗪
29:34hossein1387 I tried this in beginning of print_instructions(): unsigned char * ConfigString = (unsigned char*)*(volatile uint32_t *) 0x0000100C; printf("%s", ConfigString);
🗪
30:40Consult man 3 printf
30:40Consult man 3 printf
30:40Consult man 3 printf
31:51Make printf() print the address of config_string
31:51Make printf() print the address of config_string
31:51Make printf() print the address of config_string
32:37Run our program and view the output
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32:37Run our program and view the output
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32:37Run our program and view the output
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34:51Note how inconsistent the writing is
34:51Note how inconsistent the writing is
34:51Note how inconsistent the writing is
35:39Consult man 3 printf again
35:39Consult man 3 printf again
35:39Consult man 3 printf again
37:53Try casting config_string to void*
37:53Try casting config_string to void*
37:53Try casting config_string to void*
39:40Run our program and receive the same address
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39:40Run our program and receive the same address
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39:40Run our program and receive the same address
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40:02Set config_string without casting
40:02Set config_string without casting
40:02Set config_string without casting
40:50Run and receive the 0x100c address we were expecting
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40:50Run and receive the 0x100c address we were expecting
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40:50Run and receive the 0x100c address we were expecting
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42:26Set config_string with the cast again
42:26Set config_string with the cast again
42:26Set config_string with the cast again
44:00Run our program to see our output, with a few words on pointer dereferencing
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44:00Run our program to see our output, with a few words on pointer dereferencing
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44:00Run our program to see our output, with a few words on pointer dereferencing
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45:20Remember switching the jumper5
45:20Remember switching the jumper5
45:20Remember switching the jumper5
47:46Run and view our output
🏃
47:46Run and view our output
🏃
47:46Run and view our output
🏃
48:02Try to make print_instructions() write out the config_string using write()
48:02Try to make print_instructions() write out the config_string using write()
48:02Try to make print_instructions() write out the config_string using write()
48:41Run the program and view our correct config_string output, with a few words on where we got the config_string location
🏃
48:41Run the program and view our correct config_string output, with a few words on where we got the config_string location
🏃
48:41Run the program and view our correct config_string output, with a few words on where we got the config_string location
🏃
50:11Try printing from 0x00020004
50:11Try printing from 0x00020004
50:11Try printing from 0x00020004
53:35Run the program to see nothing at that memory location
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53:35Run the program to see nothing at that memory location
🏃
53:35Run the program to see nothing at that memory location
🏃
54:18Consult the Pinout diagram in the Getting Started Guide6
📖
54:18Consult the Pinout diagram in the Getting Started Guide6
📖
54:18Consult the Pinout diagram in the Getting Started Guide6
📖
57:51Read about the HiFive1 Boot Sequence7
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57:51Read about the HiFive1 Boot Sequence7
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57:51Read about the HiFive1 Boot Sequence7
📖
59:43Read about OTP Contents8
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59:43Read about OTP Contents8
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59:43Read about OTP Contents8
📖
1:02:29Try to print the Board Identifier
1:02:29Try to print the Board Identifier
1:02:29Try to print the Board Identifier
1:05:35Run our program and see garbage output
🏃
1:05:35Run our program and see garbage output
🏃
1:05:35Run our program and see garbage output
🏃
1:06:02Try to verify that 0x100C prints
1:06:02Try to verify that 0x100C prints
1:06:02Try to verify that 0x100C prints
1:07:44Run the program to see that it worked, and determine that the Board Identifier is not a string
🏃
1:07:44Run the program to see that it worked, and determine that the Board Identifier is not a string
🏃
1:07:44Run the program to see that it worked, and determine that the Board Identifier is not a string
🏃
1:09:41Try to printf() the board_id as an unsigned int
1:09:41Try to printf() the board_id as an unsigned int
1:09:41Try to printf() the board_id as an unsigned int
1:12:20Run our program to see some output
🏃
1:12:20Run our program to see some output
🏃
1:12:20Run our program to see some output
🏃
1:13:16Try to printf() the board_id as a char, cast to an int
1:13:16Try to printf() the board_id as a char, cast to an int
1:13:16Try to printf() the board_id as a char, cast to an int
1:14:20Run the program and hit a trap
🏃
1:14:20Run the program and hit a trap
🏃
1:14:20Run the program and hit a trap
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1:15:06hossein1387 It's a trap!
🗪
1:15:06hossein1387 It's a trap!
🗪
1:15:06hossein1387 It's a trap!
🗪
1:15:11Try to print the board_id as an int, cast to an int
1:15:11Try to print the board_id as an int, cast to an int
1:15:11Try to print the board_id as an int, cast to an int
1:15:45Run the program and hit a trap again
🏃
1:15:45Run the program and hit a trap again
🏃
1:15:45Run the program and hit a trap again
🏃
1:16:39That's all that we have time for for today
1:16:39That's all that we have time for for today
1:16:39That's all that we have time for for today
1:16:53hossein1387 I tried to setup gdb for the board, but I got my OpenOCD all screwed up. I think gdb is very useful in these situations
🗪
1:16:53hossein1387 I tried to setup gdb for the board, but I got my OpenOCD all screwed up. I think gdb is very useful in these situations
🗪
1:16:53hossein1387 I tried to setup gdb for the board, but I got my OpenOCD all screwed up. I think gdb is very useful in these situations
🗪
1:18:41Stay RISCY, everyone!
1:18:41Stay RISCY, everyone!
1:18:41Stay RISCY, everyone!