lss SYMBOL_NAME(stack_start),%esp # 自解压代码的堆栈为misc.c中定义的16K字节的数组
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
pushl $0
popfl
xorl %eax,%eax
movl $ SYMBOL_NAME(_edata),%edi
movl $ SYMBOL_NAME(_end),%ecx
subl %edi,%ecx
cld
rep
stosb
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 SYMBOL_NAME(decompress_kernel)
orl %eax,%eax # 如果返回非零,则表示为内核解压为低端和高端的两个片断
jnz 3f
popl %esi # discard address
popl %esi # real mode pointer
xorl %ebx,%ebx
ljmp $(__KERNEL_CS), $0x100000 # 运行start_kernel
3:
movl $move_routine_start,%esi
movl $0x1000,%edi
movl $move_routine_end,%ecx
subl %esi,%ecx
addl $3,%ecx
shrl $2,%ecx # 按字取整
cld
rep
movsl # 将内核片断合并代码复制到0x1000区域, 内核的片段起始为0x2000
popl %esi # discard the address
popl %ebx # real mode pointer
popl %esi # low_buffer_start 内核低端片段的起始地址
popl %ecx # lcount 内核低端片段的字节数量
popl %edx # high_buffer_start 内核高端片段的起始地址
popl %eax # hcount 内核高端片段的字节数量
movl $0x100000,%edi 内核合并的起始地址
cli # make sure we don't get interrupted
ljmp $(__KERNEL_CS), $0x1000 # and jump to the move routine
move_routine_start:
movl %ecx,%ebp
shrl $2,%ecx
rep
movsl # 按字拷贝第1个片段
movl %ebp,%ecx
andl $3,%ecx
rep
movsb # 传送不完全字
movl %edx,%esi
movl %eax,%ecx # NOTE: rep movsb won't move if %ecx == 0
addl $3,%ecx
shrl $2,%ecx # 按字对齐
rep
movsl # 按字拷贝第2个片段
movl %ebx,%esi # Restore setup pointer
xorl %ebx,%ebx
ljmp $(__KERNEL_CS), $0x100000 # 运行start_kernel
move_routine_end:
; arch/i386/boot/compressed/misc.c
#define OF(args) args
#define STATIC static
#undef memset
#undef memcpy
#define memzero(s, n) memset ((s), 0, (n))
ypedef unsigned char uch;
typedef unsigned short ush;
typedef unsigned long ulg;
#define WSIZE 0x8000
static uch *inbuf;
static uch window[WSIZE];
static unsigned insize = 0;
static unsigned inptr = 0;
static unsigned outcnt = 0;
#define ASCII_FLAG 0x01
#define CONTINUATION 0x02
#define EXTRA_FIELD 0x04
#define ORIG_NAME 0x08
#define COMMENT 0x10
#define ENCRYPTED 0x20
#define RESERVED 0xC0
#define get_byte() (inptr
#ifdef DEBUG
# define Assert(cond,msg) {if(!(cond)) error(msg);}
# define Trace(x) fprintf x
# define Tracev(x) {if (verbose) fprintf x ;}
# define Tracevv(x) {if (verbose>1) fprintf x ;}
# define Tracec(c,x) {if (verbose (c)) fprintf x ;}
# define Tracecv(c,x) {if (verbose>1 (c)) fprintf x ;}
#else
# define Assert(cond,msg)
# define Trace(x)
# define Tracev(x)
# define Tracevv(x)
# define Tracec(c,x)
# define Tracecv(c,x)
#endif
static int fill_inbuf(void);
static void flush_window(void);
static void error(char *m);
static void gzip_mark(void **);
static void gzip_release(void **);
static unsigned char *real_mode;
#define EXT_MEM_K (*(unsigned short *)(real_mode + 0x2))
#ifndef STANDARD_MEMORY_BIOS_CALL
#define ALT_MEM_K (*(unsigned long *)(real_mode + 0x1e0))
#endif
#define SCREEN_INFO (*(struct screen_info *)(real_mode+0))
extern 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);
static void error(char *m);
static void gzip_mark(void **);
static void gzip_release(void **);
static void puts(const char *);
extern int end;
static long free_mem_ptr = (long)
static long free_mem_end_ptr;
#define INPLACE_MOVE_ROUTINE 0x1000 内核片段合并代码的运行地址
#define LOW_BUFFER_START 0x2000 内核低端解压片段的起始地址
#de