SSE3052: Embedded Systems Practice

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1 SSE3052: Embedded Systems Practice Minwoo Ahn Computer Systems Laboratory Sungkyunkwan University SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong

2 Today s goal Attach new device! (LED) & Memory-mapped I/O SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 2

3 Download led skin Download led skin Download (4.3 Tue.) skin_android-24_wvga800_with_led.tgz $cd ~/Android/Sdk/platforms/android-24/skins/WVGA800 untgz in there SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 3

4 Update kernel Download goldfish $git clone $cd goldfish $git checkout b android-goldfish-n-3.10-n-dev origin/android-goldfish n-dev Download patch -> goldfish_kernel_with_led.patch Place it under goldfish $patch p1 < goldfish_kernel_with_led.patch SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 4

5 Update kernel (cont.) Kernel build $export ARCH=x86_64 $export CROSS_COMPILE=~/x86_64-linux-android-4.9/bin/x86_64- linux-android- $make x86_64_emu_defconfig $make menuconfig Device_driver -> misc -> 7segment & LED on $make j4 Move kernel Image $cd ~/Android/Sdk/system-image/android-24/google_apis/x86_64 $mv kernel-qemu kernel-qemu.old $mv kernel-ranchu kernel-ranchu.old $cp ~/goldfish/arch/x86/boot/bzimage kernel-qemu SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 5

6 Update emulator Download qemu patch Download qemu_devices_with_led.patch Place it under emu-2.2-release/external/qemu $cd emu-2.2-release/external/qemu $patch p1 < qemu_segment.patch $./android-rebuild.sh SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 6

7 Run Run avd with updated emulator $cd ~/emu-2.2-release/external/qemu/objs $./emulator avd [avd name] SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 7

8 Memory & Port mapped I/O Memory mapped I/O Port mapped I/O SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 8

9 Memory port mapped I/O Memory mapped I/O Device & memory share same address space I/O looks just like memory read/write No special command for I/O Port mapped I/O Separate address spaces Need I/O or memory select lines Special command for I/O - IN / OUT SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 9

10 Memory mapped I/O SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 10

11 Two importants Base address What is the 7segment s base(physical) address? What is the LED s base(physical) address? Move kernel Image What is the 7segment s I/O device size? What is the LED I/O device size? SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 11

12 Check device information $adb shell $cat /proc/iomem We can figure out base address & size SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 12

13 I/O memory region allocation API struct resource *request_mem_region(unsigned long start, unsigned long len, char *name) void release_mem_region(unsigned long start, unsigned long len) int check_mem_region(unsigned long start, unsigned long len) SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 13

14 Register memory region Add this codes in the device code drivers/misc/goldfish_segment.c drivers/misc/goldfish_led.c SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 14

15 Check the device file adb shell cd /dev/ There are no segment & led file SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 15

16 Register misc_device Make a device Make a file operations for your device Include miscdevice.h in device code SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 16

17 misc_device (Register device(1)) Make a misc device SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 17

18 misc_device (Register device(2)) Register a misc device (goldfish_segment.c) SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 18

19 misc_device (Register operations) Make a structure of file operations for misc device SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 19

20 misc_device (define operations) Define each operations SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 20

21 I/O memory mapping API void *ioremap(unsigned long phys_addr, unsigned long size) void *ioremap_nocache(unsigned long phys_addr, unsigned long size) void iounmap(void *virtural_addr) int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long pf, unsigned long size, pgprot_t prot) SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 21

22 misc_device (define operations cont.) Define each operations SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 22

23 Example code Download the mini_calc_mmap.c in csl.skku.edu Compile & run in your android device SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong 23

Exercise Register a misc_device for your segment&led device Make a mini calculator using segment&led./a.out [int] => print [int] on segment&led./a.out [int] [+ - x /] [int] => print result on segment&led.

24 Exercise Register a misc_device for your segment&led device Make a mini calculator using segment&led./a.out [int] => print [int] on segment&led./a.out [int] [+ - x /] [int] => print result on segment&led./a.out [+ - x /] [int] => read segment(or LED) and print result SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong (jinkyu@skku.edu) 24

SSE3052: Embedded Systems Practice

SSE3052: Embedded Systems Practice Minwoo Ahn minwoo.ahn@csl.skku.edu Computer Systems Laboratory Sungkyunkwan University http://csl.skku.edu SSE3052: Embedded Systems Practice, Spring 2018, Jinkyu Jeong