bit - search results

Let's look at five best practices for working with security in open source programming. When you write software, there's a high likelihood that you'll...

If you play video games, you've probably seen the effects of Autodesk's work. Autodesk owns the Maya and 3ds Max modeling software, the Scaleform...

  As we all know MacBook is a proprietary Laptop from Apple. Now Google entered into competition with Chromebook.  Basically Chromebook is net book...

EMC {code} invites you to a data challenge at LinuxCon, ContainerCon, CloudOpen, and MesosCon. We’ve built an exciting game with some great prizes at...

Job opportunities abound for system administrators and DevOps professionals who know Linux. But even sought-after, seasoned SysAdmins still have to go through the hiring...

The XBMC Foundation's Team Kodi last week released version 15 of its popular, open source Kodi media player and home theater framework. The "Isengard"...

I’ve spent a lot of time on the Google Play Store. During that time I have discovered plenty of really useful apps that would...

Editor's Note: This article is sponsored by FoxTechnologies, and was written by Linux.com.As companies move or extend IT from private to public clouds, and from...

Vector Light Linux, a distribution based on Slackware that uses the IceWM window manager by default, has been released and is now available for...

The new version of the kernel for stored in IDTR register is the kernel of IDT table of addresses to use fixed mapping of linear addresses, so here to fix the kernel mapping addressing mechanism to describe.Firstly ,Fixed concept mappingThe initial part of the kernel linear addresses the fourth GB of physical memory mapping system. But at least 128 MB of linear addresses is always reserved for he, as the kernel using the linear address mapping of discontinuous memory allocation and fixation of linear addresses.Secondly, fix-mapped linear addressEach fixed linear address mapping has fixed addresses the index of the structure to specify (part list only 32-bit mode).enum fixed_addresses {#ifdef CONFIG_X86_32 FIX_HOLE, FIX_VDSO,#else VSYSCALL_LAST_PAGE, VSYSCALL_FIRST_PAGE = VSYSCALL_LAST_PAGE  + ((VSYSCALL_END-VSYSCALL_START) >> PAGE_SHIFT) - 1, VVAR_PAGE, VSYSCALL_HPET, #ifdef CONFIG_PARAVIRT_CLOCK  PVCLOCK_FIXMAP_BEGIN,  PVCLOCK_FIXMAP_END = PVCLOCK_FIXMAP_BEGIN+PVCLOCK_VSYSCALL_NR_PAGES-1, #endif#endif FIX_DBGP_BASE, FIX_EARLYCON_MEM_BASE,#ifdef CONFIG_PROVIDE_OHCI1394_DMA_INIT FIX_OHCI1394_BASE,#endif#ifdef CONFIG_X86_LOCAL_APIC FIX_APIC_BASE,  /* local (CPU) APIC) -- required for SMP or not */#endif#ifdef CONFIG_X86_IO_APIC FIX_IO_APIC_BASE_0, FIX_IO_APIC_BASE_END = FIX_IO_APIC_BASE_0 + MAX_IO_APICS - 1,#endif#ifdef CONFIG_X86_VISWS_APIC FIX_CO_CPU,     /* Cobalt timer */ FIX_CO_APIC,    /* Cobalt APIC Redirection Table */ FIX_LI_PCIA,    /* Lithium PCI Bridge A */ FIX_LI_PCIB,    /* Lithium PCI Bridge B */#endif FIX_RO_IDT,     /* Virtual mapping for read-only IDT */#ifdef CONFIG_X86_32 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, #ifdef CONFIG_PCI_MMCONFIG  FIX_PCIE_MCFG, #endif#endif#ifdef CONFIG_PARAVIRT FIX_PARAVIRT_BOOTMAP,#endif FIX_TEXT_POKE1, /* reserve 2 pages for text_poke() */ FIX_TEXT_POKE0, /* first page is last, because allocation is backward */#ifdef  CONFIG_X86_INTEL_MID FIX_LNW_VRTC,#endif __end_of_permanent_fixed_addresses,#define NR_FIX_BTMAPS           64#define FIX_BTMAPS_SLOTS        4#define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) FIX_BTMAP_END = (__end_of_permanent_fixed_addresses ^ (__end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - 1)) & -PTRS_PER_PTE ? __end_of_permanent_fixed_addresses + TOTAL_FIX_BTMAPS - (__end_of_permanent_fixed_addresses & (TOTAL_FIX_BTMAPS - 1)) : __end_of_permanent_fixed_addresses,   FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,#ifdef CONFIG_X86_32 FIX_WP_TEST,#endif#ifdef CONFIG_INTEL_TXT FIX_TBOOT_BASE,#endif __end_of_fixed_addresses};Thirdly,Fixed mapping of linear addressesThe kernel using the set fixmap (independence idx, phys) and set fixmap nocache (independence idx, phys) fixed to establish the mapping of linear addresses to physical addresses. Through the clear fixmap lifting independence idx fixed by the mapping of linear addresses.telecomate.com