Dear all,
The board I used has two pieces of RAM. The virtual address start at 0x0000
0000 and
0x0200 0000. One is 4 MB(0x0000 0000) and the other is 16 MB(0x0200 0000).
But
orginal file is writted as the following. How could I modify this file to
match my
target board?
Green
----------------------------------------------------------------------------
------------
/*
* memory.c: memory initialisation code.
*
* Copyright (C) Harald Koerfgen
* Copyright (C) Jim Pick
* Copyright (C) Pavel Machek
*
* $Id: memory.c,v 1.16 2000/07/09 03:36:18 nop Exp $
*/
#include <asm/addrspace.h>
#include <asm/r39xx.h>
#include <asm/bootinfo.h>
#include <asm/page.h>
#include <linux/init.h>
#include <linux/config.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/bootmem.h>
/* ???Ӥ??O??vitec_helio?A?ҥH?|?]other ---->This line is Chinese(Big5) */
/* We don't use VTECH_HELIO. So the CONFIG_VTECH_HELIO is not defined */
#ifdef CONFIG_VTECH_HELIO
#define PROM_DEBUG
#endif
#ifdef PROM_DEBUG
extern int prom_printf(char * fmt, ...);
#endif
#ifndef CONFIG_VTECH_HELIO
int main_memory = CONFIG_MAIN_MEMORY; /* We should autoconfigure this. For
now, just let the user select. */
int exp_memory = CONFIG_EXP_MEMORY;
#define MEGA (1024*1024)
#endif
extern char _end;
extern char _fdata;
#define PFN_UP(x) (((x) + PAGE_SIZE-1) >> PAGE_SHIFT)
#define PFN_DOWN(x) ((x) >> PAGE_SHIFT)
#define PFN_ALIGN(x) (((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK)
/* Modyfied by Green 2001/02/07 */
/* This function show the message through COM port */
#ifdef JAODEBUG
extern int Jprom_printf(const char * fmt, ...);
#else
#define Jprom_printf(fmt, a...)
#endif
/* End of modification*/
#ifdef CONFIG_VTECH_HELIO /* We didn't go here insteal of
prom_meminit_other() */
static void __init prom_meminit_helio(void)
{
.....
.....
}
#else /* CONFIG_VTECH_HELIO */
static void __init prom_meminit_other(void)
{
extern unsigned long videomemory;
unsigned long free_start;
unsigned long free_end;
unsigned long start_pfn;
unsigned long bootmap_size;
unsigned long ramspace;
static char vidmem[(320 * 240 / 2) + PAGE_SIZE - 1];
/* Okay the Helio has an odd memory layout, split into 4 banks of 2M
* at the following places:
*
* 0x00000000
* 0x00400000
* 0x02000000
* 0x02400000 (add 0x80000000 for virtual address)
*
* We allocate the bootmem as a continuous bank and then free up the
* relevant memory holes. Of these the kernel will be using some
* of the first bank so be careful how we deal with it.
*/
Jprom_printf("prom_meminit_other------------>Beginning\n");
videomemory = KSEG0ADDR(PFN_ALIGN(vidmem));
start_pfn = PFN_UP((unsigned long)&_end);
/*_end=801abba0---->0x000801ac*/
free_start = PHYSADDR(PFN_ALIGN(&_end));
#ifdef CONFIG_VTECH_HELIO_EMULATOR
/* What's worse, the emulator implements two 4M banks at
* 0x0000 and 0x0200. Fixing soon, but until then:
*/
ramspace = 0x02400000; /* With holes!! */
free_end = 0x00400000;
Jprom_printf("--------------------------->ramspace: 0x%08x\n", ramspace);
bootmap_size = init_bootmem(start_pfn, ramspace >> PAGE_SHIFT);
/* Free up the *two* memory banks */
free_bootmem(free_start + bootmap_size, free_end - free_start -
bootmap_size);
free_bootmem(0x02000000, 0x00400000);
#else
ramspace = 0x02600000; /* With holes!! */
free_end = 0x00200000;
bootmap_size = init_bootmem(start_pfn, ramspace >> PAGE_SHIFT);
Jprom_printf("_end = 0x%08x-------->_end \n",&_end);
Jprom_printf("start_pfn = 0x%08x-------->FPN_UP() \n",start_pfn);
Jprom_printf("free_start = 0x%08x-------->PHYSADDR \n",free_start);
Jprom_printf("free_end = 0x%08x-------->0x00200000 \n",free_end);
Jprom_printf("bootmap_size =
0x%08x-------->bootmapsize\n",bootmap_size);
Jprom_printf("PAGE_SHIFT = 0x%08x-------->PAGE_SHIFT \n",PAGE_SHIFT);
Jprom_printf("ramspace = 0x%08x-------->0x02600000 \n",ramspace);
/* Free up the four memory banks */
free_bootmem(free_start + bootmap_size, free_end - free_start -
bootmap_size);
free_bootmem(0x00400000, 0x00200000);
free_bootmem(0x02000000, 0x00200000);
free_bootmem(0x02400000, 0x00200000);
#endif
//#ifdef CONFIG_FB
// extern unsigned long videomemory;
//#endif
// unsigned long free_start, free_end, start_pfn, bootmap_size;
// unsigned long mem_size = main_memory*MEGA;
//
// free_end = mem_size;
// if (exp_memory)
// mem_size = 0x02000000 | (exp_memory*MEGA);
//
// free_start = PHYSADDR(PFN_ALIGN(&_end));
// start_pfn = PFN_UP((unsigned long)&_end);
//
// #ifdef CONFIG_FB
/*
* This has to be in line with VIDEORAM_SIZE in r3912fb.c
*/
// switch (mips_machtype) {
// case MACH_R39XX_SHARP_MOBILON:
// case MACH_R39XX_COMPAQ:
//modified by Jao
//free_end -= 640*240;
// free_end -= 320*240;
// videomemory = KSEG0ADDR(free_end);
// break;
// case MACH_R39XX_PHILIPS_VELO:
// free_end -= 480*240/2; /* Velo has actually 2 different bit depths, this
is for 4bit.
// It is bigger that's why it is used here. */
// videomemory = KSEG0ADDR(free_end);
// break;
// case MACH_R39XX_PHILIPS_NINO:
// free_end -= 240*320/2;
// free_end &= PAGE_MASK;
// videomemory = KSEG0ADDR(free_end);
// break;
// default:
// break;
// }
//#endif
//#ifdef PROM_DEBUG
// prom_printf("free_start: 0x%08x\n", free_start);
// prom_printf("free_end: 0x%08x\n", free_end);
// prom_printf("start_pfn: 0x%08x\n", start_pfn);
// #ifdef CONFIG_FB
// prom_printf("videomemory: 0x%08x\n", videomemory);
// #endif
//#endif
/* Register all the contiguous memory with the bootmem allocator
and free it. Be careful about the bootmem freemap. */
// bootmap_size = init_bootmem(start_pfn, mem_size >> PAGE_SHIFT);
// free_bootmem(free_start + bootmap_size, free_end - free_start -
bootmap_size);
// if (exp_memory)
// free_bootmem(0x02000000, exp_memory*MEGA);
}
#endif /* CONFIG_VTECH_HELIO */
void __init prom_meminit(void)
{
Jprom_printf("&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&\n");
#if defined(CONFIG_VTECH_HELIO)
Jprom_printf("------->Here to go to prom_meminit_helio\n");
prom_meminit_helio();
#else
Jprom_printf("------->Here to go to prom_meminit_other\n");
prom_meminit_other();
#endif
}
int __init page_is_ram(unsigned long pagenr)
{
return 1;
}
/* Called from mem_init() to fixup the mem_map page settings. */
void __init prom_fixup_mem_map(unsigned long start, unsigned long end)
{
}
void prom_free_prom_memory (void)
{
}
************************************
* It's Green!! (?U?L??)
* TEL: 886-2-23776100 ext.620
* mailto:[email protected]
* Working at III(?굦?|)
* ?x?_???j?w?ϴ??ƫn???G?q216??12F
************************************
Hi Guys;
I am a newcomer for Linux world. I used largely pSOS and a little bit
WinCE. I tried to find some sort of documents about Kernel structure,
linux directory structure and dependency of source files in Linux.
I am interested in Embedded Linux due to some resource restrictions.
All I found from web so far, are installation informations and tool
usage definitions.
Your help is much appreciated.
Thanks
Sedat Sengul
I tried asking this before; never got an answer.
I suggest you just spend 20 hours or so figuring out the basic structure of
the kernel sources. It's a long run, but you'll be happy once you do.
--
Dwayne C. Litzenberger - [email protected]
- Please always Cc to me when replying to me on the lists.
- See the mail headers for GPG/advertising/homepage information.
On Fri, 23 Feb 2001, Dwayne C. Litzenberger wrote:
> I tried asking this before; never got an answer.
>
> I suggest you just spend 20 hours or so figuring out the basic structure of
> the kernel sources. It's a long run, but you'll be happy once you do.
OK, I hate to CC all these lists, but I guess it would be best
to try and end this thread now ;)
If you want to learn about the structure of the Linux kernel,
you should probably go to:
http://kernelnewbies.org/
and
irc.openprojects.net #kernelnewbies
You can also try the mailing list:
echo subscribe kernelnewbies | mail [email protected]
----
And please ... stop this thread on all the other mailing lists,
move your discussions to a more suitable forum and limit it to
that forum.
regards,
Rik
--
Virtual memory is like a game you can't win;
However, without VM there's truly nothing to lose...
http://www.surriel.com/
http://www.conectiva.com/ http://distro.conectiva.com.br/