diff --git a/arch/x86_64/Kconfig b/arch/x86_64/Kconfig index b3dbf11eb82c..715632026073 100644 --- a/arch/x86_64/Kconfig +++ b/arch/x86_64/Kconfig @@ -565,23 +565,56 @@ config CRASH_DUMP PHYSICAL_START. For more details see Documentation/kdump/kdump.txt +config RELOCATABLE + bool "Build a relocatable kernel(EXPERIMENTAL)" + depends on EXPERIMENTAL + help + Builds a relocatable kernel. This enables loading and running + a kernel binary from a different physical address than it has + been compiled for. + + One use is for the kexec on panic case where the recovery kernel + must live at a different physical address than the primary + kernel. + + Note: If CONFIG_RELOCATABLE=y, then kernel run from the address + it has been loaded at and compile time physical address + (CONFIG_PHYSICAL_START) is ignored. + config PHYSICAL_START hex "Physical address where the kernel is loaded" if (EMBEDDED || CRASH_DUMP) - default "0x1000000" if CRASH_DUMP default "0x200000" help - This gives the physical address where the kernel is loaded. Normally - for regular kernels this value is 0x200000 (2MB). But in the case - of kexec on panic the fail safe kernel needs to run at a different - address than the panic-ed kernel. This option is used to set the load - address for kernels used to capture crash dump on being kexec'ed - after panic. The default value for crash dump kernels is - 0x1000000 (16MB). This can also be set based on the "X" value as + This gives the physical address where the kernel is loaded. It + should be aligned to 2MB boundary. + + If kernel is a not relocatable (CONFIG_RELOCATABLE=n) then + bzImage will decompress itself to above physical address and + run from there. Otherwise, bzImage will run from the address where + it has been loaded by the boot loader and will ignore above physical + address. + + In normal kdump cases one does not have to set/change this option + as now bzImage can be compiled as a completely relocatable image + (CONFIG_RELOCATABLE=y) and be used to load and run from a different + address. This option is mainly useful for the folks who don't want + to use a bzImage for capturing the crash dump and want to use a + vmlinux instead. + + So if you are using bzImage for capturing the crash dump, leave + the value here unchanged to 0x200000 and set CONFIG_RELOCATABLE=y. + Otherwise if you plan to use vmlinux for capturing the crash dump + change this value to start of the reserved region (Typically 16MB + 0x1000000). In other words, it can be set based on the "X" value as specified in the "crashkernel=YM@XM" command line boot parameter passed to the panic-ed kernel. Typically this parameter is set as crashkernel=64M@16M. Please take a look at Documentation/kdump/kdump.txt for more details about crash dumps. + Usage of bzImage for capturing the crash dump is advantageous as + one does not have to build two kernels. Same kernel can be used + as production kernel and capture kernel. + Don't change this unless you know what you are doing. config SECCOMP diff --git a/arch/x86_64/boot/compressed/Makefile b/arch/x86_64/boot/compressed/Makefile index e70fa6e1da08..705a3e33d7e1 100644 --- a/arch/x86_64/boot/compressed/Makefile +++ b/arch/x86_64/boot/compressed/Makefile @@ -8,16 +8,14 @@ targets := vmlinux vmlinux.bin vmlinux.bin.gz head.o misc.o piggy.o EXTRA_AFLAGS := -traditional -AFLAGS := $(subst -m64,-m32,$(AFLAGS)) # cannot use EXTRA_CFLAGS because base CFLAGS contains -mkernel which conflicts with # -m32 -CFLAGS := -m32 -D__KERNEL__ -Iinclude -O2 -fno-strict-aliasing -LDFLAGS := -m elf_i386 +CFLAGS := -m64 -D__KERNEL__ -Iinclude -O2 -fno-strict-aliasing -fPIC -mcmodel=small -fno-builtin +LDFLAGS := -m elf_x86_64 -LDFLAGS_vmlinux := -Ttext $(IMAGE_OFFSET) -e startup_32 -m elf_i386 - -$(obj)/vmlinux: $(obj)/head.o $(obj)/misc.o $(obj)/piggy.o FORCE +LDFLAGS_vmlinux := -T +$(obj)/vmlinux: $(src)/vmlinux.lds $(obj)/head.o $(obj)/misc.o $(obj)/piggy.o FORCE $(call if_changed,ld) @: @@ -27,7 +25,7 @@ $(obj)/vmlinux.bin: vmlinux FORCE $(obj)/vmlinux.bin.gz: $(obj)/vmlinux.bin FORCE $(call if_changed,gzip) -LDFLAGS_piggy.o := -r --format binary --oformat elf32-i386 -T +LDFLAGS_piggy.o := -r --format binary --oformat elf64-x86-64 -T $(obj)/piggy.o: $(obj)/vmlinux.scr $(obj)/vmlinux.bin.gz FORCE $(call if_changed,ld) diff --git a/arch/x86_64/boot/compressed/head.S b/arch/x86_64/boot/compressed/head.S index 6f55565e4d42..c353a9266ea4 100644 --- a/arch/x86_64/boot/compressed/head.S +++ b/arch/x86_64/boot/compressed/head.S @@ -26,116 +26,262 @@ #include #include +#include #include +#include +.section ".text.head" .code32 .globl startup_32 - + startup_32: cld cli - movl $(__KERNEL_DS),%eax - movl %eax,%ds - movl %eax,%es - movl %eax,%fs - movl %eax,%gs + movl $(__KERNEL_DS), %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %ss - lss stack_start,%esp - xorl %eax,%eax -1: incl %eax # check that A20 really IS enabled - movl %eax,0x000000 # loop forever if it isn't - cmpl %eax,0x100000 - je 1b +/* Calculate the delta between where we were compiled to run + * at and where we were actually loaded at. This can only be done + * with a short local call on x86. Nothing else will tell us what + * address we are running at. The reserved chunk of the real-mode + * data at 0x34-0x3f are used as the stack for this calculation. + * Only 4 bytes are needed. + */ + leal 0x40(%esi), %esp + call 1f +1: popl %ebp + subl $1b, %ebp + +/* Compute the delta between where we were compiled to run at + * and where the code will actually run at. + */ +/* %ebp contains the address we are loaded at by the boot loader and %ebx + * contains the address where we should move the kernel image temporarily + * for safe in-place decompression. + */ + +#ifdef CONFIG_RELOCATABLE + movl %ebp, %ebx + addl $(LARGE_PAGE_SIZE -1), %ebx + andl $LARGE_PAGE_MASK, %ebx +#else + movl $CONFIG_PHYSICAL_START, %ebx +#endif + + /* Replace the compressed data size with the uncompressed size */ + subl input_len(%ebp), %ebx + movl output_len(%ebp), %eax + addl %eax, %ebx + /* Add 8 bytes for every 32K input block */ + shrl $12, %eax + addl %eax, %ebx + /* Add 32K + 18 bytes of extra slack and align on a 4K boundary */ + addl $(32768 + 18 + 4095), %ebx + andl $~4095, %ebx /* - * Initialize eflags. Some BIOS's leave bits like NT set. This would - * confuse the debugger if this code is traced. - * XXX - best to initialize before switching to protected mode. + * Prepare for entering 64 bit mode */ - pushl $0 - popfl + + /* Load new GDT with the 64bit segments using 32bit descriptor */ + leal gdt(%ebp), %eax + movl %eax, gdt+2(%ebp) + lgdt gdt(%ebp) + + /* Enable PAE mode */ + xorl %eax, %eax + orl $(1 << 5), %eax + movl %eax, %cr4 + + /* + * Build early 4G boot pagetable + */ + /* Initialize Page tables to 0*/ + leal pgtable(%ebx), %edi + xorl %eax, %eax + movl $((4096*6)/4), %ecx + rep stosl + + /* Build Level 4 */ + leal pgtable + 0(%ebx), %edi + leal 0x1007 (%edi), %eax + movl %eax, 0(%edi) + + /* Build Level 3 */ + leal pgtable + 0x1000(%ebx), %edi + leal 0x1007(%edi), %eax + movl $4, %ecx +1: movl %eax, 0x00(%edi) + addl $0x00001000, %eax + addl $8, %edi + decl %ecx + jnz 1b + + /* Build Level 2 */ + leal pgtable + 0x2000(%ebx), %edi + movl $0x00000183, %eax + movl $2048, %ecx +1: movl %eax, 0(%edi) + addl $0x00200000, %eax + addl $8, %edi + decl %ecx + jnz 1b + + /* Enable the boot page tables */ + leal pgtable(%ebx), %eax + movl %eax, %cr3 + + /* Enable Long mode in EFER (Extended Feature Enable Register) */ + movl $MSR_EFER, %ecx + rdmsr + btsl $_EFER_LME, %eax + wrmsr + + /* Setup for the jump to 64bit mode + * + * When the jump is performend we will be in long mode but + * in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1 + * (and in turn EFER.LMA = 1). To jump into 64bit mode we use + * the new gdt/idt that has __KERNEL_CS with CS.L = 1. + * We place all of the values on our mini stack so lret can + * used to perform that far jump. + */ + pushl $__KERNEL_CS + leal startup_64(%ebp), %eax + pushl %eax + + /* Enter paged protected Mode, activating Long Mode */ + movl $0x80000001, %eax /* Enable Paging and Protected mode */ + movl %eax, %cr0 + + /* Jump from 32bit compatibility mode into 64bit mode. */ + lret + + /* Be careful here startup_64 needs to be at a predictable + * address so I can export it in an ELF header. Bootloaders + * should look at the ELF header to find this address, as + * it may change in the future. + */ + .code64 + .org 0x100 +ENTRY(startup_64) + /* We come here either from startup_32 or directly from a + * 64bit bootloader. If we come here from a bootloader we depend on + * an identity mapped page table being provied that maps our + * entire text+data+bss and hopefully all of memory. + */ + + /* Setup data segments. */ + xorl %eax, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %ss + + /* Compute the decompressed kernel start address. It is where + * we were loaded at aligned to a 2M boundary. %rbp contains the + * decompressed kernel start address. + * + * If it is a relocatable kernel then decompress and run the kernel + * from load address aligned to 2MB addr, otherwise decompress and + * run the kernel from CONFIG_PHYSICAL_START + */ + + /* Start with the delta to where the kernel will run at. */ +#ifdef CONFIG_RELOCATABLE + leaq startup_32(%rip) /* - $startup_32 */, %rbp + addq $(LARGE_PAGE_SIZE - 1), %rbp + andq $LARGE_PAGE_MASK, %rbp + movq %rbp, %rbx +#else + movq $CONFIG_PHYSICAL_START, %rbp + movq %rbp, %rbx +#endif + + /* Replace the compressed data size with the uncompressed size */ + movl input_len(%rip), %eax + subq %rax, %rbx + movl output_len(%rip), %eax + addq %rax, %rbx + /* Add 8 bytes for every 32K input block */ + shrq $12, %rax + addq %rax, %rbx + /* Add 32K + 18 bytes of extra slack and align on a 4K boundary */ + addq $(32768 + 18 + 4095), %rbx + andq $~4095, %rbx + +/* Copy the compressed kernel to the end of our buffer + * where decompression in place becomes safe. + */ + leaq _end(%rip), %r8 + leaq _end(%rbx), %r9 + movq $_end /* - $startup_32 */, %rcx +1: subq $8, %r8 + subq $8, %r9 + movq 0(%r8), %rax + movq %rax, 0(%r9) + subq $8, %rcx + jnz 1b + +/* + * Jump to the relocated address. + */ + leaq relocated(%rbx), %rax + jmp *%rax + +.section ".text" +relocated: + /* * Clear BSS */ - xorl %eax,%eax - movl $_edata,%edi - movl $_end,%ecx - subl %edi,%ecx + xorq %rax, %rax + leaq _edata(%rbx), %rdi + leaq _end(%rbx), %rcx + subq %rdi, %rcx cld rep stosb + + /* Setup the stack */ + leaq user_stack_end(%rip), %rsp + + /* zero EFLAGS after setting rsp */ + pushq $0 + popfq + /* * Do the decompression, and jump to the new kernel.. */ - subl $16,%esp # place for structure on the stack - movl %esp,%eax - pushl %esi # real mode pointer as second arg - pushl %eax # address of structure as first arg - call decompress_kernel - orl %eax,%eax - jnz 3f - addl $8,%esp - xorl %ebx,%ebx - ljmp $(__KERNEL_CS), $__PHYSICAL_START + pushq %rsi # Save the real mode argument + movq %rsi, %rdi # real mode address + leaq _heap(%rip), %rsi # _heap + leaq input_data(%rip), %rdx # input_data + movl input_len(%rip), %eax + movq %rax, %rcx # input_len + movq %rbp, %r8 # output + call decompress_kernel + popq %rsi + /* - * We come here, if we were loaded high. - * We need to move the move-in-place routine down to 0x1000 - * and then start it with the buffer addresses in registers, - * which we got from the stack. + * Jump to the decompressed kernel. */ -3: - movl %esi,%ebx - movl $move_routine_start,%esi - movl $0x1000,%edi - movl $move_routine_end,%ecx - subl %esi,%ecx - addl $3,%ecx - shrl $2,%ecx - cld - rep - movsl + jmp *%rbp - popl %esi # discard the address - addl $4,%esp # real mode pointer - popl %esi # low_buffer_start - popl %ecx # lcount - popl %edx # high_buffer_start - popl %eax # hcount - movl $__PHYSICAL_START,%edi - cli # make sure we don't get interrupted - ljmp $(__KERNEL_CS), $0x1000 # and jump to the move routine - -/* - * Routine (template) for moving the decompressed kernel in place, - * if we were high loaded. This _must_ PIC-code ! - */ -move_routine_start: - movl %ecx,%ebp - shrl $2,%ecx - rep - movsl - movl %ebp,%ecx - andl $3,%ecx - rep - movsb - movl %edx,%esi - movl %eax,%ecx # NOTE: rep movsb won't move if %ecx == 0 - addl $3,%ecx - shrl $2,%ecx - rep - movsl - movl %ebx,%esi # Restore setup pointer - xorl %ebx,%ebx - ljmp $(__KERNEL_CS), $__PHYSICAL_START -move_routine_end: - - -/* Stack for uncompression */ - .align 32 -user_stack: + .data +gdt: + .word gdt_end - gdt + .long gdt + .word 0 + .quad 0x0000000000000000 /* NULL descriptor */ + .quad 0x00af9a000000ffff /* __KERNEL_CS */ + .quad 0x00cf92000000ffff /* __KERNEL_DS */ +gdt_end: + .bss +/* Stack for uncompression */ + .balign 4 +user_stack: .fill 4096,4,0 -stack_start: - .long user_stack+4096 - .word __KERNEL_DS - +user_stack_end: diff --git a/arch/x86_64/boot/compressed/misc.c b/arch/x86_64/boot/compressed/misc.c index 3755b2e394d0..fee54dbf1749 100644 --- a/arch/x86_64/boot/compressed/misc.c +++ b/arch/x86_64/boot/compressed/misc.c @@ -9,10 +9,95 @@ * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 */ +#define _LINUX_STRING_H_ 1 +#define __LINUX_BITMAP_H 1 + +#include #include #include #include +/* WARNING!! + * This code is compiled with -fPIC and it is relocated dynamically + * at run time, but no relocation processing is performed. + * This means that it is not safe to place pointers in static structures. + */ + +/* + * Getting to provable safe in place decompression is hard. + * Worst case behaviours need to be analized. + * Background information: + * + * The file layout is: + * magic[2] + * method[1] + * flags[1] + * timestamp[4] + * extraflags[1] + * os[1] + * compressed data blocks[N] + * crc[4] orig_len[4] + * + * resulting in 18 bytes of non compressed data overhead. + * + * Files divided into blocks + * 1 bit (last block flag) + * 2 bits (block type) + * + * 1 block occurs every 32K -1 bytes or when there 50% compression has been achieved. + * The smallest block type encoding is always used. + * + * stored: + * 32 bits length in bytes. + * + * fixed: + * magic fixed tree. + * symbols. + * + * dynamic: + * dynamic tree encoding. + * symbols. + * + * + * The buffer for decompression in place is the length of the + * uncompressed data, plus a small amount extra to keep the algorithm safe. + * The compressed data is placed at the end of the buffer. The output + * pointer is placed at the start of the buffer and the input pointer + * is placed where the compressed data starts. Problems will occur + * when the output pointer overruns the input pointer. + * + * The output pointer can only overrun the input pointer if the input + * pointer is moving faster than the output pointer. A condition only + * triggered by data whose compressed form is larger than the uncompressed + * form. + * + * The worst case at the block level is a growth of the compressed data + * of 5 bytes per 32767 bytes. + * + * The worst case internal to a compressed block is very hard to figure. + * The worst case can at least be boundined by having one bit that represents + * 32764 bytes and then all of the rest of the bytes representing the very + * very last byte. + * + * All of which is enough to compute an amount of extra data that is required + * to be safe. To avoid problems at the block level allocating 5 extra bytes + * per 32767 bytes of data is sufficient. To avoind problems internal to a block + * adding an extra 32767 bytes (the worst case uncompressed block size) is + * sufficient, to ensure that in the worst case the decompressed data for + * block will stop the byte before the compressed data for a block begins. + * To avoid problems with the compressed data's meta information an extra 18 + * bytes are needed. Leading to the formula: + * + * extra_bytes = (uncompressed_size >> 12) + 32768 + 18 + decompressor_size. + * + * Adding 8 bytes per 32K is a bit excessive but much easier to calculate. + * Adding 32768 instead of 32767 just makes for round numbers. + * Adding the decompressor_size is necessary as it musht live after all + * of the data as well. Last I measured the decompressor is about 14K. + * 10K of actuall data and 4K of bss. + * + */ + /* * gzip declarations */ @@ -28,15 +113,20 @@ typedef unsigned char uch; typedef unsigned short ush; typedef unsigned long ulg; -#define WSIZE 0x8000 /* Window size must be at least 32k, */ - /* and a power of two */ +#define WSIZE 0x80000000 /* Window size must be at least 32k, + * and a power of two + * We don't actually have a window just + * a huge output buffer so I report + * a 2G windows size, as that should + * always be larger than our output buffer. + */ -static uch *inbuf; /* input buffer */ -static uch window[WSIZE]; /* Sliding window buffer */ +static uch *inbuf; /* input buffer */ +static uch *window; /* Sliding window buffer, (and final output buffer) */ -static unsigned insize = 0; /* valid bytes in inbuf */ -static unsigned inptr = 0; /* index of next byte to be processed in inbuf */ -static unsigned outcnt = 0; /* bytes in output buffer */ +static unsigned insize; /* valid bytes in inbuf */ +static unsigned inptr; /* index of next byte to be processed in inbuf */ +static unsigned outcnt; /* bytes in output buffer */ /* gzip flag byte */ #define ASCII_FLAG 0x01 /* bit 0 set: file probably ASCII text */ @@ -87,8 +177,6 @@ extern unsigned char input_data[]; extern int input_len; static long bytes_out = 0; -static uch *output_data; -static unsigned long output_ptr = 0; static void *malloc(int size); static void free(void *where); @@ -98,17 +186,10 @@ static void *memcpy(void *dest, const void *src, unsigned n); static void putstr(const char *); -extern int end; -static long free_mem_ptr = (long)&end; +static long free_mem_ptr; static long free_mem_end_ptr; -#define INPLACE_MOVE_ROUTINE 0x1000 -#define LOW_BUFFER_START 0x2000 -#define LOW_BUFFER_MAX 0x90000 -#define HEAP_SIZE 0x3000 -static unsigned int low_buffer_end, low_buffer_size; -static int high_loaded =0; -static uch *high_buffer_start /* = (uch *)(((ulg)&end) + HEAP_SIZE)*/; +#define HEAP_SIZE 0x6000 static char *vidmem = (char *)0xb8000; static int vidport; @@ -218,58 +299,31 @@ static void* memcpy(void* dest, const void* src, unsigned n) */ static int fill_inbuf(void) { - if (insize != 0) { - error("ran out of input data"); - } - - inbuf = input_data; - insize = input_len; - inptr = 1; - return inbuf[0]; + error("ran out of input data"); + return 0; } /* =========================================================================== * Write the output window window[0..outcnt-1] and update crc and bytes_out. * (Used for the decompressed data only.) */ -static void flush_window_low(void) -{ - ulg c = crc; /* temporary variable */ - unsigned n; - uch *in, *out, ch; - - in = window; - out = &output_data[output_ptr]; - for (n = 0; n < outcnt; n++) { - ch = *out++ = *in++; - c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); - } - crc = c; - bytes_out += (ulg)outcnt; - output_ptr += (ulg)outcnt; - outcnt = 0; -} - -static void flush_window_high(void) -{ - ulg c = crc; /* temporary variable */ - unsigned n; - uch *in, ch; - in = window; - for (n = 0; n < outcnt; n++) { - ch = *output_data++ = *in++; - if ((ulg)output_data == low_buffer_end) output_data=high_buffer_start; - c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); - } - crc = c; - bytes_out += (ulg)outcnt; - outcnt = 0; -} - static void flush_window(void) { - if (high_loaded) flush_window_high(); - else flush_window_low(); + /* With my window equal to my output buffer + * I only need to compute the crc here. + */ + ulg c = crc; /* temporary variable */ + unsigned n; + uch *in, ch; + + in = window; + for (n = 0; n < outcnt; n++) { + ch = *in++; + c = crc_32_tab[((int)c ^ ch) & 0xff] ^ (c >> 8); + } + crc = c; + bytes_out += (ulg)outcnt; + outcnt = 0; } static void error(char *x) @@ -281,57 +335,8 @@ static void error(char *x) while(1); /* Halt */ } -static void setup_normal_output_buffer(void) -{ -#ifdef STANDARD_MEMORY_BIOS_CALL - if (RM_EXT_MEM_K < 1024) error("Less than 2MB of memory"); -#else - if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < 1024) error("Less than 2MB of memory"); -#endif - output_data = (unsigned char *)__PHYSICAL_START; /* Normally Points to 1M */ - free_mem_end_ptr = (long)real_mode; -} - -struct moveparams { - uch *low_buffer_start; int lcount; - uch *high_buffer_start; int hcount; -}; - -static void setup_output_buffer_if_we_run_high(struct moveparams *mv) -{ - high_buffer_start = (uch *)(((ulg)&end) + HEAP_SIZE); -#ifdef STANDARD_MEMORY_BIOS_CALL - if (RM_EXT_MEM_K < (3*1024)) error("Less than 4MB of memory"); -#else - if ((RM_ALT_MEM_K > RM_EXT_MEM_K ? RM_ALT_MEM_K : RM_EXT_MEM_K) < (3*1024)) error("Less than 4MB of memory"); -#endif - mv->low_buffer_start = output_data = (unsigned char *)LOW_BUFFER_START; - low_buffer_end = ((unsigned int)real_mode > LOW_BUFFER_MAX - ? LOW_BUFFER_MAX : (unsigned int)real_mode) & ~0xfff; - low_buffer_size = low_buffer_end - LOW_BUFFER_START; - high_loaded = 1; - free_mem_end_ptr = (long)high_buffer_start; - if ( (__PHYSICAL_START + low_buffer_size) > ((ulg)high_buffer_start)) { - high_buffer_start = (uch *)(__PHYSICAL_START + low_buffer_size); - mv->hcount = 0; /* say: we need not to move high_buffer */ - } - else mv->hcount = -1; - mv->high_buffer_start = high_buffer_start; -} - -static void close_output_buffer_if_we_run_high(struct moveparams *mv) -{ - if (bytes_out > low_buffer_size) { - mv->lcount = low_buffer_size; - if (mv->hcount) - mv->hcount = bytes_out - low_buffer_size; - } else { - mv->lcount = bytes_out; - mv->hcount = 0; - } -} - -int decompress_kernel(struct moveparams *mv, void *rmode) +asmlinkage void decompress_kernel(void *rmode, unsigned long heap, + uch *input_data, unsigned long input_len, uch *output) { real_mode = rmode; @@ -346,13 +351,21 @@ int decompress_kernel(struct moveparams *mv, void *rmode) lines = RM_SCREEN_INFO.orig_video_lines; cols = RM_SCREEN_INFO.orig_video_cols; - if (free_mem_ptr < 0x100000) setup_normal_output_buffer(); - else setup_output_buffer_if_we_run_high(mv); + window = output; /* Output buffer (Normally at 1M) */ + free_mem_ptr = heap; /* Heap */ + free_mem_end_ptr = heap + HEAP_SIZE; + inbuf = input_data; /* Input buffer */ + insize = input_len; + inptr = 0; + + if ((ulg)output & 0x1fffffUL) + error("Destination address not 2M aligned"); + if ((ulg)output >= 0xffffffffffUL) + error("Destination address too large"); makecrc(); putstr(".\nDecompressing Linux..."); gunzip(); putstr("done.\nBooting the kernel.\n"); - if (high_loaded) close_output_buffer_if_we_run_high(mv); - return high_loaded; + return; } diff --git a/arch/x86_64/boot/compressed/vmlinux.lds b/arch/x86_64/boot/compressed/vmlinux.lds new file mode 100644 index 000000000000..94c13e557fb4 --- /dev/null +++ b/arch/x86_64/boot/compressed/vmlinux.lds @@ -0,0 +1,44 @@ +OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64", "elf64-x86-64") +OUTPUT_ARCH(i386:x86-64) +ENTRY(startup_64) +SECTIONS +{ + /* Be careful parts of head.S assume startup_32 is at + * address 0. + */ + . = 0; + .text : { + _head = . ; + *(.text.head) + _ehead = . ; + *(.text.compressed) + _text = .; /* Text */ + *(.text) + *(.text.*) + _etext = . ; + } + .rodata : { + _rodata = . ; + *(.rodata) /* read-only data */ + *(.rodata.*) + _erodata = . ; + } + .data : { + _data = . ; + *(.data) + *(.data.*) + _edata = . ; + } + .bss : { + _bss = . ; + *(.bss) + *(.bss.*) + *(COMMON) + . = ALIGN(8); + _end = . ; + . = ALIGN(4096); + pgtable = . ; + . = . + 4096 * 6; + _heap = .; + } +} diff --git a/arch/x86_64/boot/compressed/vmlinux.scr b/arch/x86_64/boot/compressed/vmlinux.scr index 1ed9d791f863..bd1429ce193e 100644 --- a/arch/x86_64/boot/compressed/vmlinux.scr +++ b/arch/x86_64/boot/compressed/vmlinux.scr @@ -1,9 +1,10 @@ SECTIONS { - .data : { + .text.compressed : { input_len = .; - LONG(input_data_end - input_data) input_data = .; - *(.data) - input_data_end = .; + LONG(input_data_end - input_data) input_data = .; + *(.data) + output_len = . - 4; + input_data_end = .; } } diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S index c211e52f1333..36aa98a6d15c 100644 --- a/arch/x86_64/kernel/head.S +++ b/arch/x86_64/kernel/head.S @@ -5,6 +5,7 @@ * Copyright (C) 2000 Pavel Machek * Copyright (C) 2000 Karsten Keil * Copyright (C) 2001,2002 Andi Kleen + * Copyright (C) 2005 Eric Biederman */ @@ -17,95 +18,127 @@ #include #include #include - + /* we are not able to switch in one step to the final KERNEL ADRESS SPACE - * because we need identity-mapped pages on setup so define __START_KERNEL to - * 0x100000 for this stage - * + * because we need identity-mapped pages. + * */ .text .section .bootstrap.text - .code32 - .globl startup_32 -/* %bx: 1 if coming from smp trampoline on secondary cpu */ -startup_32: - - /* - * At this point the CPU runs in 32bit protected mode (CS.D = 1) with - * paging disabled and the point of this file is to switch to 64bit - * long mode with a kernel mapping for kerneland to jump into the - * kernel virtual addresses. - * There is no stack until we set one up. - */ - - /* Initialize the %ds segment register */ - movl $__KERNEL_DS,%eax - movl %eax,%ds - - /* Load new GDT with the 64bit segments using 32bit descriptor */ - lgdt pGDT32 - __START_KERNEL_map - - /* If the CPU doesn't support CPUID this will double fault. - * Unfortunately it is hard to check for CPUID without a stack. - */ - - /* Check if extended functions are implemented */ - movl $0x80000000, %eax - cpuid - cmpl $0x80000000, %eax - jbe no_long_mode - /* Check if long mode is implemented */ - mov $0x80000001, %eax - cpuid - btl $29, %edx - jnc no_long_mode - - /* - * Prepare for entering 64bits mode - */ - - /* Enable PAE mode */ - xorl %eax, %eax - btsl $5, %eax - movl %eax, %cr4 - - /* Setup early boot stage 4 level pagetables */ - movl $(init_level4_pgt - __START_KERNEL_map), %eax - movl %eax, %cr3 - - /* Setup EFER (Extended Feature Enable Register) */ - movl $MSR_EFER, %ecx - rdmsr - - /* Enable Long Mode */ - btsl $_EFER_LME, %eax - - /* Make changes effective */ - wrmsr - - xorl %eax, %eax - btsl $31, %eax /* Enable paging and in turn activate Long Mode */ - btsl $0, %eax /* Enable protected mode */ - /* Make changes effective */ - movl %eax, %cr0 - /* - * At this point we're in long mode but in 32bit compatibility mode - * with EFER.LME = 1, CS.L = 0, CS.D = 1 (and in turn - * EFER.LMA = 1). Now we want to jump in 64bit mode, to do that we use - * the new gdt/idt that has __KERNEL_CS with CS.L = 1. - */ - ljmp $__KERNEL_CS, $(startup_64 - __START_KERNEL_map) - .code64 - .org 0x100 .globl startup_64 startup_64: + + /* + * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1, + * and someone has loaded an identity mapped page table + * for us. These identity mapped page tables map all of the + * kernel pages and possibly all of memory. + * + * %esi holds a physical pointer to real_mode_data. + * + * We come here either directly from a 64bit bootloader, or from + * arch/x86_64/boot/compressed/head.S. + * + * We only come here initially at boot nothing else comes here. + * + * Since we may be loaded at an address different from what we were + * compiled to run at we first fixup the physical addresses in our page + * tables and then reload them. + */ + + /* Compute the delta between the address I am compiled to run at and the + * address I am actually running at. + */ + leaq _text(%rip), %rbp + subq $_text - __START_KERNEL_map, %rbp + + /* Is the address not 2M aligned? */ + movq %rbp, %rax + andl $~LARGE_PAGE_MASK, %eax + testl %eax, %eax + jnz bad_address + + /* Is the address too large? */ + leaq _text(%rip), %rdx + movq $PGDIR_SIZE, %rax + cmpq %rax, %rdx + jae bad_address + + /* Fixup the physical addresses in the page table + */ + addq %rbp, init_level4_pgt + 0(%rip) + addq %rbp, init_level4_pgt + (258*8)(%rip) + addq %rbp, init_level4_pgt + (511*8)(%rip) + + addq %rbp, level3_ident_pgt + 0(%rip) + addq %rbp, level3_kernel_pgt + (510*8)(%rip) + + /* Add an Identity mapping if I am above 1G */ + leaq _text(%rip), %rdi + andq $LARGE_PAGE_MASK, %rdi + + movq %rdi, %rax + shrq $PUD_SHIFT, %rax + andq $(PTRS_PER_PUD - 1), %rax + jz ident_complete + + leaq (level2_spare_pgt - __START_KERNEL_map + _KERNPG_TABLE)(%rbp), %rdx + leaq level3_ident_pgt(%rip), %rbx + movq %rdx, 0(%rbx, %rax, 8) + + movq %rdi, %rax + shrq $PMD_SHIFT, %rax + andq $(PTRS_PER_PMD - 1), %rax + leaq __PAGE_KERNEL_LARGE_EXEC(%rdi), %rdx + leaq level2_spare_pgt(%rip), %rbx + movq %rdx, 0(%rbx, %rax, 8) +ident_complete: + + /* Fixup the kernel text+data virtual addresses + */ + leaq level2_kernel_pgt(%rip), %rdi + leaq 4096(%rdi), %r8 + /* See if it is a valid page table entry */ +1: testq $1, 0(%rdi) + jz 2f + addq %rbp, 0(%rdi) + /* Go to the next page */ +2: addq $8, %rdi + cmp %r8, %rdi + jne 1b + + /* Fixup phys_base */ + addq %rbp, phys_base(%rip) + +#ifdef CONFIG_SMP + addq %rbp, trampoline_level4_pgt + 0(%rip) + addq %rbp, trampoline_level4_pgt + (511*8)(%rip) +#endif +#ifdef CONFIG_ACPI_SLEEP + addq %rbp, wakeup_level4_pgt + 0(%rip) + addq %rbp, wakeup_level4_pgt + (511*8)(%rip) +#endif + + /* Due to ENTRY(), sometimes the empty space gets filled with + * zeros. Better take a jmp than relying on empty space being + * filled with 0x90 (nop) + */ + jmp secondary_startup_64 ENTRY(secondary_startup_64) - /* We come here either from startup_32 - * or directly from a 64bit bootloader. - * Since we may have come directly from a bootloader we - * reload the page tables here. + /* + * At this point the CPU runs in 64bit mode CS.L = 1 CS.D = 1, + * and someone has loaded a mapped page table. + * + * %esi holds a physical pointer to real_mode_data. + * + * We come here either from startup_64 (using physical addresses) + * or from trampoline.S (using virtual addresses). + * + * Using virtual addresses from trampoline.S removes the need + * to have any identity mapped pages in the kernel page table + * after the boot processor executes this code. */ /* Enable PAE mode and PGE */ @@ -116,8 +149,14 @@ ENTRY(secondary_startup_64) /* Setup early boot stage 4 level pagetables. */ movq $(init_level4_pgt - __START_KERNEL_map), %rax + addq phys_base(%rip), %rax movq %rax, %cr3 + /* Ensure I am executing from virtual addresses */ + movq $1f, %rax + jmp *%rax +1: + /* Check if nx is implemented */ movl $0x80000001, %eax cpuid @@ -126,17 +165,11 @@ ENTRY(secondary_startup_64) /* Setup EFER (Extended Feature Enable Register) */ movl $MSR_EFER, %ecx rdmsr - - /* Enable System Call */ - btsl $_EFER_SCE, %eax - - /* No Execute supported? */ - btl $20,%edi + btsl $_EFER_SCE, %eax /* Enable System Call */ + btl $20,%edi /* No Execute supported? */ jnc 1f btsl $_EFER_NX, %eax -1: - /* Make changes effective */ - wrmsr +1: wrmsr /* Make changes effective */ /* Setup cr0 */ #define CR0_PM 1 /* protected mode */ @@ -163,7 +196,7 @@ ENTRY(secondary_startup_64) * addresses where we're currently running on. We have to do that here * because in 32bit we couldn't load a 64bit linear address. */ - lgdt cpu_gdt_descr + lgdt cpu_gdt_descr(%rip) /* set up data segments. actually 0 would do too */ movl $__KERNEL_DS,%eax @@ -214,6 +247,9 @@ initial_code: init_rsp: .quad init_thread_union+THREAD_SIZE-8 +bad_address: + jmp bad_address + ENTRY(early_idt_handler) cmpl $2,early_recursion_flag(%rip) jz 1f @@ -242,23 +278,7 @@ early_idt_msg: early_idt_ripmsg: .asciz "RIP %s\n" -.code32 -ENTRY(no_long_mode) - /* This isn't an x86-64 CPU so hang */ -1: - jmp 1b - -.org 0xf00 - .globl pGDT32 -pGDT32: - .word gdt_end-cpu_gdt_table-1 - .long cpu_gdt_table-__START_KERNEL_map - -.org 0xf10 -ljumpvector: - .long startup_64-__START_KERNEL_map - .word __KERNEL_CS - +.balign PAGE_SIZE ENTRY(stext) ENTRY(_stext) @@ -303,7 +323,7 @@ NEXT_PAGE(level2_ident_pgt) * Don't set NX because code runs from these pages. */ PMDS(0x0000000000000000, __PAGE_KERNEL_LARGE_EXEC, PTRS_PER_PMD) - + NEXT_PAGE(level2_kernel_pgt) /* 40MB kernel mapping. The kernel code cannot be bigger than that. When you change this change KERNEL_TEXT_SIZE in page.h too. */ @@ -313,6 +333,9 @@ NEXT_PAGE(level2_kernel_pgt) /* Module mapping starts here */ .fill (PTRS_PER_PMD - (KERNEL_TEXT_SIZE/PMD_SIZE)),8,0 +NEXT_PAGE(level2_spare_pgt) + .fill 512,8,0 + #undef PMDS #undef NEXT_PAGE @@ -330,6 +353,10 @@ gdt: .endr #endif +ENTRY(phys_base) + /* This must match the first entry in level2_kernel_pgt */ + .quad 0x0000000000000000 + /* We need valid kernel segments for data and code in long mode too * IRET will check the segment types kkeil 2000/10/28 * Also sysret mandates a special GDT layout diff --git a/arch/x86_64/kernel/suspend_asm.S b/arch/x86_64/kernel/suspend_asm.S index bfbe00763c68..16d183f67bc1 100644 --- a/arch/x86_64/kernel/suspend_asm.S +++ b/arch/x86_64/kernel/suspend_asm.S @@ -71,9 +71,10 @@ loop: jmp loop done: /* go back to the original page tables */ - leaq init_level4_pgt(%rip), %rax - subq $__START_KERNEL_map, %rax - movq %rax, %cr3 + movq $(init_level4_pgt - __START_KERNEL_map), %rax + addq phys_base(%rip), %rax + movq %rax, %cr3 + /* Flush TLB, including "global" things (vmalloc) */ movq mmu_cr4_features(%rip), %rax movq %rax, %rdx diff --git a/include/asm-x86_64/page.h b/include/asm-x86_64/page.h index 4974433bbf34..40a24d0df090 100644 --- a/include/asm-x86_64/page.h +++ b/include/asm-x86_64/page.h @@ -61,6 +61,8 @@ typedef struct { unsigned long pgd; } pgd_t; typedef struct { unsigned long pgprot; } pgprot_t; +extern unsigned long phys_base; + #define pte_val(x) ((x).pte) #define pmd_val(x) ((x).pmd) #define pud_val(x) ((x).pud) @@ -101,14 +103,14 @@ typedef struct { unsigned long pgprot; } pgprot_t; #define PAGE_OFFSET __PAGE_OFFSET /* Note: __pa(&symbol_visible_to_c) should be always replaced with __pa_symbol. - Otherwise you risk miscompilation. */ + Otherwise you risk miscompilation. */ #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET) /* __pa_symbol should be used for C visible symbols. This seems to be the official gcc blessed way to do such arithmetic. */ #define __pa_symbol(x) \ ({unsigned long v; \ asm("" : "=r" (v) : "0" (x)); \ - (v - __START_KERNEL_map); }) + ((v - __START_KERNEL_map) + phys_base); }) #define __va(x) ((void *)((unsigned long)(x)+PAGE_OFFSET)) #ifdef CONFIG_FLATMEM