diff options
Diffstat (limited to 'arch/x86_64/kernel/setup.c')
| -rw-r--r-- | arch/x86_64/kernel/setup.c | 30 |
1 files changed, 22 insertions, 8 deletions
diff --git a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c index ebc3c33b1c6c..f0870bef24d1 100644 --- a/arch/x86_64/kernel/setup.c +++ b/arch/x86_64/kernel/setup.c @@ -571,17 +571,28 @@ static inline void copy_edd(void) #endif #define EBDA_ADDR_POINTER 0x40E -static void __init reserve_ebda_region(void) + +unsigned __initdata ebda_addr; +unsigned __initdata ebda_size; + +static void discover_ebda(void) { - unsigned int addr; - /** + /* * there is a real-mode segmented pointer pointing to the * 4K EBDA area at 0x40E */ - addr = *(unsigned short *)phys_to_virt(EBDA_ADDR_POINTER); - addr <<= 4; - if (addr) - reserve_bootmem_generic(addr, PAGE_SIZE); + ebda_addr = *(unsigned short *)EBDA_ADDR_POINTER; + ebda_addr <<= 4; + + ebda_size = *(unsigned short *)(unsigned long)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; } void __init setup_arch(char **cmdline_p) @@ -627,6 +638,8 @@ void __init setup_arch(char **cmdline_p) check_efer(); + discover_ebda(); + init_memory_mapping(0, (end_pfn_map << PAGE_SHIFT)); dmi_scan_machine(); @@ -669,7 +682,8 @@ void __init setup_arch(char **cmdline_p) reserve_bootmem_generic(0, PAGE_SIZE); /* reserve ebda region */ - reserve_ebda_region(); + if (ebda_addr) + reserve_bootmem_generic(ebda_addr, ebda_size); #ifdef CONFIG_SMP /* |