[LinuxBIOS] Convert hex to dec

[Joseph Smith]

Hello,
Got another silly C newbie question.
If I want to convert a hex value to decimal, would this work?

value = ff /* Hex value */

sscanf(value, %d, &value)

Is the variable "value" now 255??

Thanks - Joe

[Peter Stuge]

On Wed, Jul 04, 2007 at 09:22:54AM -0400, Joseph Smith wrote:
> Hello,
> Got another silly C newbie question.
> If I want to convert a hex value to decimal, would this work?
>
> value = ff /* Hex value */
>
> sscanf(value, %d, &value)
>
> Is the variable "value" now 255??

Hexadecimal, decimal and octal are different ways for us humans to
express numbers to computers, but no matter what we use, they are
always stored in binary form in the machine.

Thus, there is no difference between a number in hexadecimal or
decimal. We do however have to tell the computer which formatting we
want when the computer should show us the numbers.

unsigned char value;

value=0xff; /* hexadecimal */

/* %d means print number in decimal */
printf("value in decimal is now %d\n",value);

value=135; /* decimal */

/* %x means print in hex */
printf("value in hexadecimal is now %x\n",value);

value=0254; /* octal */

if(0xac==0254)
  printf("C knows that 0xac == 0254 because they are both == %d\n",value);

Have a look at the printf man page for your nearest C library to
learn about all the good stuff you can put into formatting strings
besides just %d and %x.

//Peter

[Uwe Hermann]

On Wed, Jul 04, 2007 at 05:29:56PM +0200, Peter Stuge wrote:
> On Wed, Jul 04, 2007 at 09:22:54AM -0400, Joseph Smith wrote:
> > Hello,
> > Got another silly C newbie question.
> > If I want to convert a hex value to decimal, would this work?
> >
> > value = ff /* Hex value */
> >
> > sscanf(value, %d, &value)
> >
> > Is the variable "value" now 255??
>
> Hexadecimal, decimal and octal are different ways for us humans to
> express numbers to computers, but no matter what we use, they are
> always stored in binary form in the machine.
>
> Thus, there is no difference between a number in hexadecimal or
> decimal. We do however have to tell the computer which formatting we
> want when the computer should show us the numbers.
>
> unsigned char value;
>
> value=0xff; /* hexadecimal */
>
> /* %d means print number in decimal */
> printf("value in decimal is now %d\n",value);
>
> value=135; /* decimal */
>
> /* %x means print in hex */
> printf("value in hexadecimal is now %x\n",value);
>
> value=0254; /* octal */
>
> if(0xac==0254)
>   printf("C knows that 0xac == 0254 because they are both == %d\n",value);
>
> Have a look at the printf man page for your nearest C library to
> learn about all the good stuff you can put into formatting strings
> besides just %d and %x.

I use some aliases in my .bashrc which are pretty handy for converting
HEX or BINARY or DECIMAL:

alias HEX="ruby -e 'printf("0x%X\n", ARGV[0])'"
alias DEC="ruby -e 'printf("%d\n", ARGV[0])'"
alias BIN="ruby -e 'printf("%bb\n", ARGV[0])'"

(You can replace 'ruby' with 'perl' if you want)

Usage:

$ HEX 78
0x4E
$ BIN 0x6a
1101010b
$ DEC 0x72
114

HTH, Uwe.

[Peter Stuge]

On Wed, Jul 04, 2007 at 07:47:11PM +0200, Uwe Hermann wrote:
> I use some aliases in my .bashrc which are pretty handy for converting
> HEX or BINARY or DECIMAL:
>
> alias HEX="ruby -e 'printf("0x%X\n", ARGV[0])'"
> alias DEC="ruby -e 'printf("%d\n", ARGV[0])'"
> alias BIN="ruby -e 'printf("%bb\n", ARGV[0])'"
>
> (You can replace 'ruby' with 'perl' if you want)

bash has printf too; try printf 0x%X\n 128

//Peter

[Alan Carvalho de Assis]

2007/7/4, Peter Stuge :
> On Wed, Jul 04, 2007 at 07:47:11PM +0200, Uwe Hermann wrote:
> > I use some aliases in my .bashrc which are pretty handy for converting
> > HEX or BINARY or DECIMAL:
> >
> > alias HEX="ruby -e 'printf("0x%X\n", ARGV[0])'"
> > alias DEC="ruby -e 'printf("%d\n", ARGV[0])'"
> > alias BIN="ruby -e 'printf("%bb\n", ARGV[0])'"
> >
> > (You can replace 'ruby' with 'perl' if you want)
>
> bash has printf too; try printf 0x%X\n 128

Yes, printf at shell is very useful, I use this command to reset BIOS CMOS:

# printf "\x2E" | dd bs=1 seek=112 of=/dev/port
# printf "\xFF" | dd bs=1 seek=113 of=/dev/port

It sends 0x2E to port 0x70 and 0xFF to port 0x71.
> //Peter

Alan

[Stefan Reinauer]

* Uwe Hermann  [070704 19:47]:
> I use some aliases in my .bashrc which are pretty handy for converting
> HEX or BINARY or DECIMAL:
>
> alias HEX="ruby -e 'printf("0x%X\n", ARGV[0])'"
> alias DEC="ruby -e 'printf("%d\n", ARGV[0])'"
> alias BIN="ruby -e 'printf("%bb\n", ARGV[0])'"
>
> Usage:
>
> $ HEX 78
> 0x4E
> $ BIN 0x6a
> 1101010b
> $ DEC 0x72
> 114

cool stuff. Can it easily be fixed to convert  binary into hex or dec,
too?

[Uwe Hermann]

On Thu, Jul 05, 2007 at 05:58:18AM +0200, Stefan Reinauer wrote:
> Uwe Hermann  [070704 19:47]:
> > I use some aliases in my .bashrc which are pretty handy for converting
> > HEX or BINARY or DECIMAL:
> >
> > alias HEX="ruby -e 'printf("0x%X\n", ARGV[0])'"
> > alias DEC="ruby -e 'printf("%d\n", ARGV[0])'"
> > alias BIN="ruby -e 'printf("%bb\n", ARGV[0])'"
> >
> > Usage:
> >
> > $ HEX 78
> > 0x4E
> > $ BIN 0x6a
> > 1101010b
> > $ DEC 0x72
> > 114
>
> cool stuff. Can it easily be fixed to convert  binary into hex or dec,
> too?

Yes, that works already (the syntax is a bit strange, though):

$ HEX 0b10101010
0xAA
$ DEC 0b10000011
131

Uwe.

[Joseph Smith]

Quoting Uwe Hermann :
> On Thu, Jul 05, 2007 at 05:58:18AM +0200, Stefan Reinauer wrote:
> > Uwe Hermann  [070704 19:47]:
> > > I use some aliases in my .bashrc which are pretty handy for converting
> > > HEX or BINARY or DECIMAL:
> > >
> > > alias HEX="ruby -e 'printf("0x%X\n", ARGV[0])'"
> > > alias DEC="ruby -e 'printf("%d\n", ARGV[0])'"
> > > alias BIN="ruby -e 'printf("%bb\n", ARGV[0])'"
> > >
> > > Usage:
> > >
> > > $ HEX 78
> > > 0x4E
> > > $ BIN 0x6a
> > > 1101010b
> > > $ DEC 0x72
> > > 114
> >
> > cool stuff. Can it easily be fixed to convert  binary into hex or dec,
> > too?
>
> Yes, that works already (the syntax is a bit strange, though):
>
> $ HEX 0b10101010
> 0xAA
> $ DEC 0b10000011
> 131
>
> Uwe.

Ok so how would I go about doing this is print_debug than?
Something like:

value=0xff; /* hexadecimal */

/* %d means print number in decimal */
print_debug("value in decimal is now %d\n",value);

Thanks - Joe

[Peter Stuge]

On Wed, Jul 04, 2007 at 04:36:57PM -0400, Joseph Smith wrote:
> > printf("value in hexadecimal is now %x\n",value);
>
> Ok so how would I go about doing this is print_debug than?

Sorry.

print_debug() in v2 doesn't support variable number of arguments
(varargs) but maybe you could backport printk() from v3 lib/console.c ?

//Peter

[Joseph Smith]

Quoting Peter Stuge :
> On Wed, Jul 04, 2007 at 04:36:57PM -0400, Joseph Smith wrote:
> > > printf("value in hexadecimal is now %x\n",value);
> >
> > Ok so how would I go about doing this is print_debug than?
>
> Sorry.
>
> print_debug() in v2 doesn't support variable number of arguments
> (varargs) but maybe you could backport printk() from v3 lib/console.c ?
>
> //Peter

Maybe V3 at a later date, I'm still working on porting my board to V2.

Ok, if the computer sees everthing in binary, than maybe I can try  
something like this?

#define PRINT_DEBUG_DEC(d)

value=0xff; /* hexadecimal */

print_debug("value in decimal is now ");
PRINT_DEBUG_DEC(value);
print_debug(" Is this working?\r\n");

What do you think?

Thanks - Joe

[Stefan Reinauer]

* Joseph Smith  [070706 17:41]:
> #define PRINT_DEBUG_DEC(d)
>
> value=0xff; /* hexadecimal */
>
> print_debug("value in decimal is now ");
> PRINT_DEBUG_DEC(value);
> print_debug(" Is this working?\r\n");

Since it seems to be for debug only, you can also use
print_debug_hex8
print_debug_hex16
print_debug_hex32

Stefan

[Joseph Smith]

Quoting Stefan Reinauer :
> Joseph Smith  [070706 17:41]:
> > #define PRINT_DEBUG_DEC(d)
> >
> > value=0xff; /* hexadecimal */
> >
> > print_debug("value in decimal is now ");
> > PRINT_DEBUG_DEC(value);
> > print_debug(" Is this working?\r\n");
>
> Since it seems to be for debug only, you can also use
> print_debug_hex8
> print_debug_hex16
> print_debug_hex32
>
> Stefan

But that is the whole problem. I already says "print_debug_hex8". I  
want it to display decimal not hex.....

Thanks - Joe

[Stefan Reinauer]

* Joseph Smith  [070707 00:59]:
> But that is the whole problem. I already says "print_debug_hex8". I want it 
>  to display decimal not hex.....

You could look at print_debug_hex8 and implement the _dec8 functions.

I don't think it's worth the effort though. What's wrong with hex?

It's all debug anyways.

[Joseph Smith]

Quoting Stefan Reinauer :
> Joseph Smith  [070707 00:59]:
> > But that is the whole problem. I already says "print_debug_hex8". I want it
> >  to display decimal not hex.....
>
> You could look at print_debug_hex8 and implement the _dec8 functions.
>
> I don't think it's worth the effort though. What's wrong with hex?
>
> It's all debug anyways.

I kow it is just for aesthetics but, If it is an easy implimentation,  
I will check it out. What file is print_debug_hex8 in anyways?

Thanks Again - Joe

[ron minnich]

joe, print in hex is trivial.

In the limit, it's this simple:
putc(hexarray((a>>4)&0xf); putc(hexarray(a&0xf));

decimal is harder, and, in romcc, not worth the effort.

I think this whole decimal escapade is not a good use of time.

ron

[Indrek Kruusa]

Ühel kenal päeval (laupäev 07 juuli 2007 1:59 am) kirjutas Joseph Smith:
> Quoting Stefan Reinauer :
> > Joseph Smith  [070706 17:41]:
> > > #define PRINT_DEBUG_DEC(d)
> > >
> > > value=0xff; /* hexadecimal */
> > >
> > > print_debug("value in decimal is now ");
> > > PRINT_DEBUG_DEC(value);
> > > print_debug(" Is this working?\r\n");
> >
> > Since it seems to be for debug only, you can also use
> > print_debug_hex8
> > print_debug_hex16
> > print_debug_hex32
> >
> > Stefan
>
> But that is the whole problem. I already says "print_debug_hex8". I
> want it to display decimal not hex.....

/* Print CPU clock */

p3 = cpu_clk / 100;
        p2 = (cpu_clk - p3 * 100)/10;
        p1 = cpu_clk - p3 * 100 - p2*10;

print_info("CPU ");
        print_info_char(48+p3);
        print_info_char(48+p2);
        print_info_char(48+p1);
        print_info(" MHz\r\n");

:)

cheers,
Indrek

[Peter Stuge]

inline void print_info_dec(unsigned long value,unsigned long res) {
  for(;res;res/=10)
    print_info_char('0'+value/res%10);
}

On Mon, Jul 09, 2007 at 09:43:49AM +0300, Indrek Kruusa wrote:
>     print_info("CPU ");

print_info_dec(cpu_clk,100);
>     print_info(" MHz\r\n");

Note this only prints the modulus while Indrek's code indicates that
the value does not fit in 3 positions by printing a non-digit
hundreds character.

Multiply the resoluton by 10 to get more digits. 1000=4, 10000=5 etc.

Omitting leading 0:s would need some state to be kept and cost one
more register.

//Peter

[Joseph Smith]

Quoting Peter Stuge :
> inline void print_info_dec(unsigned long value,unsigned long res) {
>   for(;res;res/=10)
>     print_info_char('0'+value/res%10);
> }
>
> On Mon, Jul 09, 2007 at 09:43:49AM +0300, Indrek Kruusa wrote:
> >     print_info("CPU ");
>
> print_info_dec(cpu_clk,100);
> >     print_info(" MHz\r\n");
>
> Note this only prints the modulus while Indrek's code indicates that
> the value does not fit in 3 positions by printing a non-digit
> hundreds character.
>
> Multiply the resoluton by 10 to get more digits. 1000=4, 10000=5 etc.
>
> Omitting leading 0:s would need some state to be kept and cost one
> more register.
>
> //Peter

Actually, I found this in one of the scripts:

printk_debug("Setting RAM size to %d\n", tomk);

Thanks - Joe

[Stefan Reinauer]

* Joseph Smith  [070709 23:04]:
> Actually, I found this in one of the scripts:
>
> printk_debug("Setting RAM size to %d\n", tomk);

print_debug only works in preram stage

printk_debug only works in ram stage

with some exceptions. :-)

Stefan

[Stefan Reinauer]

* Peter Stuge  [070706 16:28]:
> On Wed, Jul 04, 2007 at 04:36:57PM -0400, Joseph Smith wrote:
> > > printf("value in hexadecimal is now %x\n",value);
> >
> > Ok so how would I go about doing this is print_debug than?
>
> Sorry.
>
> print_debug() in v2 doesn't support variable number of arguments
> (varargs) but maybe you could backport printk() from v3 lib/console.c ?

There are already 6 printk/f variants in v2. So one could assume this
has been tried 5 times already ;)

[Joseph Smith]

Quoting Peter Stuge :
> On Wed, Jul 04, 2007 at 09:22:54AM -0400, Joseph Smith wrote:
> > Hello,
> > Got another silly C newbie question.
> > If I want to convert a hex value to decimal, would this work?
> >
> > value = ff /* Hex value */
> >
> > sscanf(value, %d, &value)
> >
> > Is the variable "value" now 255??
>
> Hexadecimal, decimal and octal are different ways for us humans to
> express numbers to computers, but no matter what we use, they are
> always stored in binary form in the machine.
>
> Thus, there is no difference between a number in hexadecimal or
> decimal. We do however have to tell the computer which formatting we
> want when the computer should show us the numbers.
>
> unsigned char value;
>
> value=0xff; /* hexadecimal */
>
> /* %d means print number in decimal */
> printf("value in decimal is now %d\n",value);
>
> value=135; /* decimal */
>
> /* %x means print in hex */
> printf("value in hexadecimal is now %x\n",value);
>
> value=0254; /* octal */
>
> if(0xac==0254)
>   printf("C knows that 0xac == 0254 because they are both == %d\n",value);
>
> Have a look at the printf man page for your nearest C library to
> learn about all the good stuff you can put into formatting strings
> besides just %d and %x.
>
> //Peter

Ok so how would I go about doing this is print_debug than?
Something like:

value=0xff; /* hexadecimal */

/* %d means print number in decimal */
print_debug("value in decimal is now %d\n",value);

Thanks - Joe