using char-lcd in linux

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Do you have an LCD? If not, don't include the LCD driver in the menuconfig.

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yes ,i have ,i use DE2-70. I donnot know how to fix it

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What is the name of the LCD peripheral? it needs to match what it's called in the driver.

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Copy the kernel header file lcd_16207.h to uClinux-dist/linux-2.6.x/source/drivers/char/

Goto:

http://www.nioswiki.com/operatingsystems/uclinux/lcd_16207

for source file.

I had to make the following modification to bypass the cache in the driver code in lcd_16207.h:

# define ADR_LCD_COMMAND na_lcd_16207_0 + 0x80000000# define ADR_LCD_READY (na_lcd_16207_0 + 0x80000000 + 4)# define ADR_LCD_DATA (na_lcd_16207_0 + 0x80000000 + 8)# define ADR_LCD_READ (na_lcd_16207_0 + 0x80000000 + 12)

In lcd_16207.c change# include "linux/lcd_16207.h" to# include "lcd_16207.h"

The device name in de SOPC builder "lcd_16207_0"!!

If the character driver for the display is loaded in your kernel,

and you use the MSH shell which allows redirection from the echo command, you should be able to do something as simple as:

switch to the MSH shell:

/> msh

# echo "Hello World!" > /dev/lcd16207

You will need to have the MSH shell enabled in the kernel and the 'echo' command from busybox.

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Copy the kernel header file lcd_16207.h to uClinux-dist/linux-2.6.x/source/drivers/char/

Goto:

http://www.nioswiki.com/operatingsystems/uclinux/lcd_16207

for source file.

I had to make the following modification to bypass the cache in the driver code in lcd_16207.h:

# define ADR_LCD_COMMAND na_lcd_16207_0 + 0x80000000
# define ADR_LCD_READY (na_lcd_16207_0 + 0x80000000 + 4)
# define ADR_LCD_DATA (na_lcd_16207_0 + 0x80000000 + 8)
# define ADR_LCD_READ (na_lcd_16207_0 + 0x80000000 + 12)

In lcd_16207.c change# include "linux/lcd_16207.h" to# include "lcd_16207.h"

The device name in de SOPC builder "na_lcd_16207_0"!!

If the character driver for the display is loaded in your kernel,

and you use the MSH shell which allows redirection from the echo command, you should be able to do something as simple as:

switch to the MSH shell:

/> msh

# echo "Hello World!" > /dev/lcd16207

You will need to have the MSH shell enabled in the kernel and the 'echo' command from busybox.

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Thank you very much， though it doesnot work.

I think na_lcd_16207_0 is something about address.

i am using linux-mmu .do you have any other suggestions?

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Thank you very much， though it doesnot work.

I think na_lcd_16207_0 is something about address.

i am using linux-mmu .do you have any other suggestions?

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Me tip is usefull for a system without a mmu. I think the + 0x8000000 is not needed with a mmu based system.

Is jou system running and you can compile linux?

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Me tip is usefull for a system without a mmu. I think the + 0x8000000 is not needed with a mmu based system.

Is jou system running and you can compile linux?

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yes,everything goes fine,except adding lcd

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yes,everything goes fine,except adding lcd

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What do you mean with "except adding lcd"? Compile errors?

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What do you mean with "except adding lcd"? Compile errors?

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yes,when compiling after add lcd :

error:"na_lcd_16207_0" undeclared

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yes,when compiling after add lcd :

error:"na_lcd_16207_0" undeclared

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Oeps little typo on my side!!

The device name in de SOPC builder "na_lcd_16207_0"!! this is wrong!!

change it to "lcd_16207_0"!!

Regenerate the custom_fpga.h with the new .sopcinfo file (use sopc-create-header-files tool) and recompile linux.