add code for data abort and prefetch abort errors

simple implementation just to dump the registers's
value, will add more features later

Signed-off-by: Le Min <lemin9538@gmail.com>
fs/vfs.c getdent, 4 bytes aligin when get the string

Signed-off-by: Le Min <lemin9538@gmail.com>
add lock and bitmap for tty allocation in case of race

Signed-off-by: Le Min <lemin9538@gmail.com>
workaround the slab free issue

when release a slab, if the usage of the page
which the slab belongs is 0, then the page will
automaticlly freed, but since there may slab list
to the slab plist and they are not deleted at the
same time. it will cause problems when get a same
size's slab

from these issue, it can be found that there are
lots issue of memory manergment system. we need
a new and strong MM system. will try to improve
it later

Signed-off-by: Le Min <lemin9538@gmail.com>
remove unused char in panic function

Signed-off-by: Le Min <lemin9538@gmail.com>
remove some unused function of mm and slab

Signed-off-by: Le Min <lemin9538@gmail.com>
syscall write and read using size to indicate the string length

when print log, using size as the contion to terminate
the tty write

Signed-off-by: Le Min <lemin9538@gmail.com>
define macro DEBUG_LMFS to control the log of LMFS

Signed-off-by: Le Min <lemin9538@gmail.com>
add _sys_access syscall and open ttyS0 when process is created

Signed-off-by: Le Min <lemin9538@gmail.com>
using fs_debug to control the log print of fnode.c

Signed-off-by: Le Min <lemin9538@gmail.com>
delete unused logs for vfs let code more clearly

Signed-off-by: Le Min <lemin9538@gmail.com>
build idle task early and check current process when panic

Signed-off-by: Le Min <lemin9538@gmail.com>
define fs_debug and add _sys_access to header file

Signed-off-by: Le Min <lemin9538@gmail.com>
fix some bugs of devfs and mount it when system start

when copy fnode the list_head can not copied directy
so pass the pointer of dnode to the fs system

Signed-off-by: Le Min <lemin9538@gmail.com>
add file_desc init call and fix the bug when fill argv and envp

Signed-off-by: Le Min <lemin9538@gmail.com>
enhanced mount syscall and enable devfs mounting

Signed-off-by: Le Min <lemin9538@gmail.com>
add syscall directory to implement syscall handler

Signed-off-by: Le Min <lemin9538@gmail.com>
add wshell which is downloaded from github.com

Signed-off-by: Le Min <lemin9538@gmail.com>
fix some issues in MM make it more stable

Signed-off-by: Le,Min <lemin9538@gmail.com>
add some new operations for files

1: fmmap and fmsync
2: call back for close file: release_fnode

Signed-off-by: Le,Min <lemin9538@gmail.com>