diff options
Diffstat (limited to 'arch/x86/kernel/head_32.S')
| -rw-r--r-- | arch/x86/kernel/head_32.S | 123 |
1 files changed, 64 insertions, 59 deletions
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S index bcece91dd31..767d6c43de3 100644 --- a/arch/x86/kernel/head_32.S +++ b/arch/x86/kernel/head_32.S @@ -60,16 +60,18 @@ #define PAGE_TABLE_SIZE(pages) ((pages) / PTRS_PER_PGD) #endif +/* Number of possible pages in the lowmem region */ +LOWMEM_PAGES = (((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) + /* Enough space to fit pagetables for the low memory linear map */ -MAPPING_BEYOND_END = \ - PAGE_TABLE_SIZE(((1<<32) - __PAGE_OFFSET) >> PAGE_SHIFT) << PAGE_SHIFT +MAPPING_BEYOND_END = PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT /* * Worst-case size of the kernel mapping we need to make: - * the worst-case size of the kernel itself, plus the extra we need - * to map for the linear map. + * a relocatable kernel can live anywhere in lowmem, so we need to be able + * to map all of lowmem. */ -KERNEL_PAGES = (KERNEL_IMAGE_SIZE + MAPPING_BEYOND_END)>>PAGE_SHIFT +KERNEL_PAGES = LOWMEM_PAGES INIT_MAP_SIZE = PAGE_TABLE_SIZE(KERNEL_PAGES) * PAGE_SIZE_asm RESERVE_BRK(pagetables, INIT_MAP_SIZE) @@ -83,6 +85,8 @@ RESERVE_BRK(pagetables, INIT_MAP_SIZE) */ __HEAD ENTRY(startup_32) + movl pa(stack_start),%ecx + /* test KEEP_SEGMENTS flag to see if the bootloader is asking us to not reload segments */ testb $(1<<6), BP_loadflags(%esi) @@ -97,7 +101,9 @@ ENTRY(startup_32) movl %eax,%es movl %eax,%fs movl %eax,%gs + movl %eax,%ss 2: + leal -__PAGE_OFFSET(%ecx),%esp /* * Clear BSS first so that there are no surprises... @@ -124,7 +130,7 @@ ENTRY(startup_32) movsl movl pa(boot_params) + NEW_CL_POINTER,%esi andl %esi,%esi - jz 1f # No comand line + jz 1f # No command line movl $pa(boot_command_line),%edi movl $(COMMAND_LINE_SIZE/4),%ecx rep @@ -137,49 +143,13 @@ ENTRY(startup_32) movl %eax, pa(olpc_ofw_pgd) #endif -#ifdef CONFIG_PARAVIRT - /* This is can only trip for a broken bootloader... */ - cmpw $0x207, pa(boot_params + BP_version) - jb default_entry - - /* Paravirt-compatible boot parameters. Look to see what architecture - we're booting under. */ - movl pa(boot_params + BP_hardware_subarch), %eax - cmpl $num_subarch_entries, %eax - jae bad_subarch - - movl pa(subarch_entries)(,%eax,4), %eax - subl $__PAGE_OFFSET, %eax - jmp *%eax - -bad_subarch: -WEAK(lguest_entry) -WEAK(xen_entry) - /* Unknown implementation; there's really - nothing we can do at this point. */ - ud2a - - __INITDATA - -subarch_entries: - .long default_entry /* normal x86/PC */ - .long lguest_entry /* lguest hypervisor */ - .long xen_entry /* Xen hypervisor */ - .long default_entry /* Moorestown MID */ -num_subarch_entries = (. - subarch_entries) / 4 -.previous -#endif /* CONFIG_PARAVIRT */ - /* * Initialize page tables. This creates a PDE and a set of page * tables, which are located immediately beyond __brk_base. The variable * _brk_end is set up to point to the first "safe" location. * Mappings are created both at virtual address 0 (identity mapping) * and PAGE_OFFSET for up to _end. - * - * Note that the stack is not yet set up! */ -default_entry: #ifdef CONFIG_X86_PAE /* @@ -259,7 +229,42 @@ page_pde_offset = (__PAGE_OFFSET >> 20); movl $pa(initial_pg_fixmap)+PDE_IDENT_ATTR,%eax movl %eax,pa(initial_page_table+0xffc) #endif - jmp 3f + +#ifdef CONFIG_PARAVIRT + /* This is can only trip for a broken bootloader... */ + cmpw $0x207, pa(boot_params + BP_version) + jb default_entry + + /* Paravirt-compatible boot parameters. Look to see what architecture + we're booting under. */ + movl pa(boot_params + BP_hardware_subarch), %eax + cmpl $num_subarch_entries, %eax + jae bad_subarch + + movl pa(subarch_entries)(,%eax,4), %eax + subl $__PAGE_OFFSET, %eax + jmp *%eax + +bad_subarch: +WEAK(lguest_entry) +WEAK(xen_entry) + /* Unknown implementation; there's really + nothing we can do at this point. */ + ud2a + + __INITDATA + +subarch_entries: + .long default_entry /* normal x86/PC */ + .long lguest_entry /* lguest hypervisor */ + .long xen_entry /* Xen hypervisor */ + .long default_entry /* Moorestown MID */ +num_subarch_entries = (. - subarch_entries) / 4 +.previous +#else + jmp default_entry +#endif /* CONFIG_PARAVIRT */ + /* * Non-boot CPU entry point; entered from trampoline.S * We can't lgdt here, because lgdt itself uses a data segment, but @@ -279,8 +284,11 @@ ENTRY(startup_32_smp) movl %eax,%es movl %eax,%fs movl %eax,%gs + movl pa(stack_start),%ecx + movl %eax,%ss + leal -__PAGE_OFFSET(%ecx),%esp #endif /* CONFIG_SMP */ -3: +default_entry: /* * New page tables may be in 4Mbyte page mode and may @@ -314,6 +322,10 @@ ENTRY(startup_32_smp) subl $0x80000001, %eax cmpl $(0x8000ffff-0x80000001), %eax ja 6f + + /* Clear bogus XD_DISABLE bits */ + call verify_cpu + mov $0x80000001, %eax cpuid /* Execute Disable bit supported? */ @@ -340,8 +352,8 @@ ENTRY(startup_32_smp) movl %eax,%cr0 /* ..and set paging (PG) bit */ ljmp $__BOOT_CS,$1f /* Clear prefetch and normalize %eip */ 1: - /* Set up the stack pointer */ - lss stack_start,%esp + /* Shift the stack pointer to a virtual address */ + addl $__PAGE_OFFSET, %esp /* * Initialize eflags. Some BIOS's leave bits like NT set. This would @@ -353,9 +365,7 @@ ENTRY(startup_32_smp) #ifdef CONFIG_SMP cmpb $0, ready - jz 1f /* Initial CPU cleans BSS */ - jmp checkCPUtype -1: + jnz checkCPUtype #endif /* CONFIG_SMP */ /* @@ -463,14 +473,7 @@ is386: movl $2,%ecx # set MP cld # gcc2 wants the direction flag cleared at all times pushl $0 # fake return address for unwinder -#ifdef CONFIG_SMP - movb ready, %cl movb $1, ready - cmpb $0,%cl # the first CPU calls start_kernel - je 1f - movl (stack_start), %esp -1: -#endif /* CONFIG_SMP */ jmp *(initial_code) /* @@ -609,6 +612,8 @@ ignore_int: #endif iret +#include "verify_cpu.S" + __REFDATA .align 4 ENTRY(initial_code) @@ -661,15 +666,15 @@ ENTRY(initial_page_table) #endif .data +.balign 4 ENTRY(stack_start) .long init_thread_union+THREAD_SIZE - .long __BOOT_DS - -ready: .byte 0 early_recursion_flag: .long 0 +ready: .byte 0 + int_msg: .asciz "Unknown interrupt or fault at: %p %p %p\n" |