src/mboot.cpp

Idź do dokumentacji tego pliku.

/***********************************************************
*PANALIX 0.06, (c) Adrian Panasiuk 2002-4                  *
*adek336[at]o2.pl, panalix.prv.pl                          *
*under GPLv3 license                                       *
*                                                          *
*panalix - small osdev project                             *
************************************************************
*       mboot.cpp, version 1.1                             *
************************************************************
*                                                          *
*get config from the multiboot compliant bootloader        *
*                                                          *
*27'04'04- fork from o.05 branch's mboot.cpp(1.1)          *
*                                                          *
***********************************************************/

#include "src/common/shared.hpp"
#include "src/module/elf.hpp"
#include "src/memory/align.hpp"
#include "src/memory/alloc4k.hpp"
#include "src/mboot.hpp"

namespace Mboot {


/*we copy the struct to save it from overwriting*/
mboot_struct multiboot_info = *mb_info;

//preserve the syms data by changing the first_free_page var
void init()
 {
uint32 i;
/*      Get the highest adress of a section of the kernel's helping data, and then
        adjust first_free_page to a page above it. This way it won't get overwritten    */
mboot_sht *sht= mboot_syms();
uint32 max_addr=0, n;
Elf32_shdr *sect;

        if (sht != NULL)
         {
                max_addr=sht->addr+(sht->num*sht->entry_size);
                for (i=0;i<sht->num;i++)
                 {
                        sect= (Elf32_shdr*) LMA2VIRT(sht->addr + sht->entry_size*i);

                        n=sect->sh_addr+sect->sh_size;
                        if (n>mem_kernel_start)
                                n-=mem_kernel_start-mem_physical;
                        max_addr= MAX(n, max_addr);
                 }
                Memory::Physical::first_free_page=
                        align_up(max_addr, PAGE_ALIGN)/PAGE_SIZE;
//              sysfail(max_addr);
//              Memory::Physical::first_free_page=
//                      align_up(sht->addr+(sht->num*sht->entry_size), PAGE_ALIGN)/PAGE_SIZE;
         }

/*      Get the highest address of a kernel module, adjust first_free_page. Then it won't get overwritten by
        system tables   */
int mcnt=mods_count();
        if (mcnt == 0) return ;

struct mod_info *m;
        m= mods_info(mcnt-1);   //the last module- the highest address (is this always true?)
        Memory::Physical::first_free_page=MAX(Memory::Physical::first_free_page, align_up(m->mod_end, PAGE_ALIGN)/PAGE_ALIGN);
 }

/*returns the number of modules*/
uint32 mods_count()
 {
/*check if module info is provided in multiboot_info*/
        if (multiboot_info.flags && DEF_MBOOT_MODS == DEF_MBOOT_MODS)
/*if yes, return it*/
                return multiboot_info.mods_count;

/*if not, return no modules availlable*/
        return 0;
 }

/*returns a pointer to modinfo no. n*/
/*n = 0, first module, etc.*/
//will return physical adresses below 1 Mib
mod_info *mods_info(uint32 n)
 {
/*check if module info is provided in multiboot_info*/
        if (multiboot_info.flags && DEF_MBOOT_MODS != DEF_MBOOT_MODS)
/*if not, return 0*/
                return (mod_info*) NULL;

/*check if there is a module no. n*/
        if (n + 1 > mods_count()) return 0;

        return (mod_info*) ((uint32) multiboot_info.mods_addr + sizeof(mod_info) * n);
 }

/*checks if syms info is availlable. if yes, return the struct*/
mboot_sht *mboot_syms()
 {
/*check if syms info's availlable*/
        if (multiboot_info.flags && DEF_MBOOT_ELF_SH != DEF_MBOOT_ELF_SH)
                return 0;

/*return the data*/
        return (struct mboot_sht*)(&multiboot_info.syms);
 }

 };     /*namespace Mboot*/

/***********************************************************
*                                                          *
*panalix 0.06 (c) Adrian Panasiuk 2002-4                   *
*adek336[at]o2.pl, panalix.prv.pl                          *
*                                                          *
************************************************************/

---