diff options
Diffstat (limited to 'arch/x86/kernel/head64.c')
| -rw-r--r-- | arch/x86/kernel/head64.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c index 87e031d4abf..58438bafedc 100644 --- a/arch/x86/kernel/head64.c +++ b/arch/x86/kernel/head64.c @@ -21,6 +21,7 @@ #include <asm/tlbflush.h> #include <asm/sections.h> #include <asm/kdebug.h> +#include <asm/e820.h> static void __init zap_identity_mappings(void) { @@ -48,6 +49,35 @@ static void __init copy_bootdata(char *real_mode_data) } } +#define EBDA_ADDR_POINTER 0x40E + +static __init void reserve_ebda(void) +{ + unsigned ebda_addr, ebda_size; + + /* + * there is a real-mode segmented pointer pointing to the + * 4K EBDA area at 0x40E + */ + ebda_addr = *(unsigned short *)__va(EBDA_ADDR_POINTER); + ebda_addr <<= 4; + + if (!ebda_addr) + return; + + ebda_size = *(unsigned short *)__va(ebda_addr); + + /* Round EBDA up to pages */ + if (ebda_size == 0) + ebda_size = 1; + ebda_size <<= 10; + ebda_size = round_up(ebda_size + (ebda_addr & ~PAGE_MASK), PAGE_SIZE); + if (ebda_size > 64*1024) + ebda_size = 64*1024; + + reserve_early(ebda_addr, ebda_addr + ebda_size); +} + void __init x86_64_start_kernel(char * real_mode_data) { int i; @@ -75,5 +105,23 @@ void __init x86_64_start_kernel(char * real_mode_data) pda_init(0); copy_bootdata(__va(real_mode_data)); + reserve_early(__pa_symbol(&_text), __pa_symbol(&_end)); + + /* Reserve INITRD */ + if (boot_params.hdr.type_of_loader && boot_params.hdr.ramdisk_image) { + unsigned long ramdisk_image = boot_params.hdr.ramdisk_image; + unsigned long ramdisk_size = boot_params.hdr.ramdisk_size; + unsigned long ramdisk_end = ramdisk_image + ramdisk_size; + reserve_early(ramdisk_image, ramdisk_end); + } + + reserve_ebda(); + + /* + * At this point everything still needed from the boot loader + * or BIOS or kernel text should be early reserved or marked not + * RAM in e820. All other memory is free game. + */ + start_kernel(); } |