sys/src/boot/efi/fs.c

   1 #include <u.h>
   2 #include "fns.h"
   3 #include "efi.h"
   4
   5 typedef struct {
   6         UINT64          Revision;
   7         void            *Open;
   8         void            *Close;
   9         void            *Delete;
  10         void            *Read;
  11         void            *Write;
  12         void            *GetPosition;
  13         void            *SetPosition;
  14         void            *GetInfo;
  15         void            *SetInfo;
  16         void            *Flush;
  17         void            *OpenEx;
  18         void            *ReadEx;
  19         void            *WriteEx;
  20         void            *FlushEx;
  21 } EFI_FILE_PROTOCOL;
  22
  23 typedef struct {
  24         UINT64          Revision;
  25         void            *OpenVolume;
  26 } EFI_SIMPLE_FILE_SYSTEM_PROTOCOL;
  27
  28 static
  29 EFI_GUID EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID = {
  30         0x0964e5b22, 0x6459, 0x11d2,
  31         0x8e, 0x39, 0x00, 0xa0,
  32         0xc9, 0x69, 0x72, 0x3b,
  33 };
  34
  35 static
  36 EFI_FILE_PROTOCOL *fsroot;
  37
  38 static void
  39 towpath(CHAR16 *w, int nw, char *s)
  40 {
  41         int i;
  42
  43         for(i=0; *s && i<nw-1; i++){
  44                 *w = *s++;
  45                 if(*w == '/')
  46                         *w = '\\';
  47                 w++;
  48         }
  49         *w = 0;
  50 }
  51
  52 static void*
  53 fsopen(char *name)
  54 {
  55         CHAR16 wname[MAXPATH];
  56         EFI_FILE_PROTOCOL *fp;
  57
  58         if(fsroot == nil)
  59                 return nil;
  60
  61         towpath(wname, MAXPATH, name);
  62
  63         fp = nil;
  64         if(eficall(fsroot->Open, fsroot, &fp, wname, (UINT64)1, (UINT64)1))
  65                 return nil;
  66         return fp;
  67 }
  68
  69 static int
  70 fsread(void *f, void *data, int len)
  71 {
  72         UINTN size;
  73
  74         size = len;
  75         if(eficall(((EFI_FILE_PROTOCOL*)f)->Read, f, &size, data))
  76                 return 0;
  77         return (int)size;
  78 }
  79
  80 static void
  81 fsclose(void *f)
  82 {
  83         eficall(((EFI_FILE_PROTOCOL*)f)->Close, f);
  84 }
  85
  86 int
  87 fsinit(void **pf)
  88 {
  89         EFI_SIMPLE_FILE_SYSTEM_PROTOCOL *fs;
  90
  91         fs = nil;
  92         fsroot = nil;
  93         if(eficall(ST->BootServices->LocateProtocol,
  94                 &EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID, nil, &fs))
  95                 return -1;
  96         if(eficall(fs->OpenVolume, fs, &fsroot)){
  97                 fsroot = nil;
  98                 return -1;
  99         }
 100
 101         read = fsread;
 102         close = fsclose;
 103         open = fsopen;
 104
 105         if(pf != nil)
 106                 *pf = fsopen("/plan9.ini");
 107
 108         return 0;
 109 }