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1 /** @file
2   Basic command line parser for EBL (Embedded Boot Loader)
3 
4   Copyright (c) 2007, Intel Corporation. All rights reserved.<BR>
5   Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
6   (C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>
7 
8   This program and the accompanying materials
9   are licensed and made available under the terms and conditions of the BSD License
10   which accompanies this distribution.  The full text of the license may be found at
11   http://opensource.org/licenses/bsd-license.php
12 
13   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
14   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
15 
16 
17 **/
18 
19 #include "Ebl.h"
20 
21 // Globals for command history processing
22 INTN mCmdHistoryEnd     = -1;
23 INTN mCmdHistoryStart   = -1;
24 INTN mCmdHistoryCurrent = -1;
25 CHAR8 mCmdHistory[MAX_CMD_HISTORY][MAX_CMD_LINE];
26 CHAR8 *mCmdBlank = "";
27 
28 // Globals to remember current screen geometry
29 UINTN gScreenColumns;
30 UINTN gScreenRows;
31 
32 // Global to turn on/off breaking commands with prompts before they scroll the screen
33 BOOLEAN gPageBreak = TRUE;
34 
35 VOID
RingBufferIncrement(IN INTN * Value)36 RingBufferIncrement (
37   IN  INTN  *Value
38   )
39 {
40   *Value = *Value + 1;
41 
42   if (*Value >= MAX_CMD_HISTORY) {
43     *Value = 0;
44   }
45 }
46 
47 VOID
RingBufferDecrement(IN INTN * Value)48 RingBufferDecrement (
49   IN  INTN  *Value
50   )
51 {
52   *Value = *Value - 1;
53 
54   if (*Value < 0) {
55     *Value = MAX_CMD_HISTORY - 1;
56   }
57 }
58 
59 /**
60   Save this command in the circular history buffer. Older commands are
61   overwritten with newer commands.
62 
63   @param  Cmd   Command line to archive the history of.
64 
65   @return None
66 
67 **/
68 VOID
SetCmdHistory(IN CHAR8 * Cmd)69 SetCmdHistory (
70   IN  CHAR8 *Cmd
71   )
72 {
73   // Don't bother adding empty commands to the list
74   if (AsciiStrLen(Cmd) != 0) {
75 
76     // First entry
77     if (mCmdHistoryStart == -1) {
78       mCmdHistoryStart   = 0;
79       mCmdHistoryEnd     = 0;
80     } else {
81       // Record the new command at the next index
82       RingBufferIncrement(&mCmdHistoryStart);
83 
84       // If the next index runs into the end index, shuffle end back by one
85       if (mCmdHistoryStart == mCmdHistoryEnd) {
86         RingBufferIncrement(&mCmdHistoryEnd);
87       }
88     }
89 
90     // Copy the new command line into the ring buffer
91     AsciiStrnCpyS (&mCmdHistory[mCmdHistoryStart][0], MAX_CMD_LINE, Cmd, MAX_CMD_LINE);
92   }
93 
94   // Reset the command history for the next up arrow press
95   mCmdHistoryCurrent = mCmdHistoryStart;
96 }
97 
98 
99 /**
100   Retreave data from the Command History buffer. Direction maps into up arrow
101   an down arrow on the command line
102 
103   @param  Direction  Command forward or back
104 
105   @return The Command history based on the Direction
106 
107 **/
108 CHAR8 *
GetCmdHistory(IN UINT16 Direction)109 GetCmdHistory (
110   IN UINT16   Direction
111   )
112 {
113   CHAR8 *HistoricalCommand = NULL;
114 
115   // No history yet?
116   if (mCmdHistoryCurrent == -1) {
117     HistoricalCommand = mCmdBlank;
118     goto Exit;
119   }
120 
121   if (Direction == SCAN_UP) {
122     HistoricalCommand = &mCmdHistory[mCmdHistoryCurrent][0];
123 
124     // if we just echoed the last command, hang out there, don't wrap around
125     if (mCmdHistoryCurrent == mCmdHistoryEnd) {
126       goto Exit;
127     }
128 
129     // otherwise, back up by one
130     RingBufferDecrement(&mCmdHistoryCurrent);
131 
132   } else if (Direction == SCAN_DOWN) {
133 
134     // if we last echoed the start command, put a blank prompt out
135     if (mCmdHistoryCurrent == mCmdHistoryStart) {
136       HistoricalCommand = mCmdBlank;
137       goto Exit;
138     }
139 
140     // otherwise increment the current pointer and return that command
141     RingBufferIncrement(&mCmdHistoryCurrent);
142     RingBufferIncrement(&mCmdHistoryCurrent);
143 
144     HistoricalCommand = &mCmdHistory[mCmdHistoryCurrent][0];
145     RingBufferDecrement(&mCmdHistoryCurrent);
146   }
147 
148 Exit:
149   return HistoricalCommand;
150 }
151 
152 
153 /**
154   Parse the CmdLine and break it up into Argc (arg count) and Argv (array of
155   pointers to each argument). The Cmd buffer is altered and separators are
156   converted to string terminators. This allows Argv to point into CmdLine.
157   A CmdLine can support multiple commands. The next command in the command line
158   is returned if it exists.
159 
160   @param  CmdLine String to parse for a set of commands
161   @param  Argc    Returns the number of arguments in the CmdLine current command
162   @param  Argv    Argc pointers to each string in CmdLine
163 
164   @return Next Command in the command line or NULL if non exists
165 **/
166 CHAR8 *
ParseArguments(IN CHAR8 * CmdLine,OUT UINTN * Argc,OUT CHAR8 ** Argv)167 ParseArguments (
168   IN  CHAR8  *CmdLine,
169   OUT UINTN  *Argc,
170   OUT CHAR8  **Argv
171   )
172 {
173   UINTN   Arg;
174   CHAR8   *Char;
175   BOOLEAN LookingForArg;
176   BOOLEAN InQuote;
177 
178   *Argc = 0;
179   if (AsciiStrLen (CmdLine) == 0) {
180     return NULL;
181   }
182 
183   // Walk a single command line. A CMD_SEPARATOR allows multiple commands on a single line
184   InQuote       = FALSE;
185   LookingForArg = TRUE;
186   for (Char = CmdLine, Arg = 0; *Char != '\0'; Char++) {
187     if (!InQuote && *Char == CMD_SEPARATOR) {
188       break;
189     }
190 
191     // Perform any text conversion here
192     if (*Char == '\t') {
193       // TAB to space
194       *Char = ' ';
195     }
196 
197     if (LookingForArg) {
198       // Look for the beginning of an Argv[] entry
199       if (*Char == '"') {
200         Argv[Arg++] = ++Char;
201         LookingForArg = FALSE;
202         InQuote = TRUE;
203       } else if (*Char != ' ') {
204         Argv[Arg++] = Char;
205         LookingForArg = FALSE;
206       }
207     } else {
208       // Looking for the terminator of an Argv[] entry
209       if (!InQuote && (*Char == ' ')) {
210         *Char = '\0';
211         LookingForArg = TRUE;
212       } else if (!InQuote && (*Char == '"') && (*(Char-1) != '\\')) {
213         InQuote = TRUE;
214       } else if (InQuote && (*Char == '"') && (*(Char-1) != '\\')) {
215         *Char = '\0';
216         InQuote = FALSE;
217       }
218     }
219   }
220 
221   *Argc = Arg;
222 
223   if (*Char == CMD_SEPARATOR) {
224     // Replace the command delimiter with null and return pointer to next command line
225     *Char = '\0';
226     return ++Char;
227   }
228 
229   return NULL;
230 }
231 
232 
233 /**
234   Return a keypress or optionally timeout if a timeout value was passed in.
235   An optional callback function is called every second when waiting for a
236   timeout.
237 
238   @param  Key           EFI Key information returned
239   @param  TimeoutInSec  Number of seconds to wait to timeout
240   @param  CallBack      Callback called every second during the timeout wait
241 
242   @return EFI_SUCCESS  Key was returned
243   @return EFI_TIMEOUT  If the TimoutInSec expired
244 
245 **/
246 EFI_STATUS
247 EFIAPI
EblGetCharKey(IN OUT EFI_INPUT_KEY * Key,IN UINTN TimeoutInSec,IN EBL_GET_CHAR_CALL_BACK CallBack OPTIONAL)248 EblGetCharKey (
249   IN OUT EFI_INPUT_KEY            *Key,
250   IN     UINTN                    TimeoutInSec,
251   IN     EBL_GET_CHAR_CALL_BACK   CallBack   OPTIONAL
252   )
253 {
254   EFI_STATUS    Status;
255   UINTN         WaitCount;
256   UINTN         WaitIndex;
257   EFI_EVENT     WaitList[2];
258 
259   WaitCount   = 1;
260   WaitList[0] = gST->ConIn->WaitForKey;
261   if (TimeoutInSec != 0) {
262     // Create a time event for 1 sec duration if we have a timeout
263     gBS->CreateEvent (EVT_TIMER, 0, NULL, NULL, &WaitList[1]);
264     gBS->SetTimer (WaitList[1], TimerPeriodic, EFI_SET_TIMER_TO_SECOND);
265     WaitCount++;
266   }
267 
268   for (;;) {
269     Status = gBS->WaitForEvent (WaitCount, WaitList, &WaitIndex);
270     ASSERT_EFI_ERROR (Status);
271 
272     switch (WaitIndex) {
273     case 0:
274       // Key event signaled
275       Status = gST->ConIn->ReadKeyStroke (gST->ConIn, Key);
276       if (!EFI_ERROR (Status)) {
277         if (WaitCount == 2) {
278           gBS->CloseEvent (WaitList[1]);
279         }
280         return EFI_SUCCESS;
281       }
282       break;
283 
284     case 1:
285       // Periodic 1 sec timer signaled
286       TimeoutInSec--;
287       if (CallBack != NULL) {
288         // Call the users callback function if registered
289         CallBack (TimeoutInSec);
290       }
291       if (TimeoutInSec == 0) {
292         gBS->CloseEvent (WaitList[1]);
293         return EFI_TIMEOUT;
294       }
295       break;
296     default:
297       ASSERT (FALSE);
298     }
299   }
300 }
301 
302 
303 /**
304   This routine is used prevent command output data from scrolling off the end
305   of the screen. The global gPageBreak is used to turn on or off this feature.
306   If the CurrentRow is near the end of the screen pause and print out a prompt
307   If the use hits Q to quit return TRUE else for any other key return FALSE.
308   PrefixNewline is used to figure out if a newline is needed before the prompt
309   string. This depends on the last print done before calling this function.
310   CurrentRow is updated by one on a call or set back to zero if a prompt is
311   needed.
312 
313   @param  CurrentRow  Used to figure out if its the end of the page and updated
314   @param  PrefixNewline  Did previous print issue a newline
315 
316   @return TRUE if Q was hit to quit, FALSE in all other cases.
317 
318 **/
319 BOOLEAN
320 EFIAPI
EblAnyKeyToContinueQtoQuit(IN UINTN * CurrentRow,IN BOOLEAN PrefixNewline)321 EblAnyKeyToContinueQtoQuit (
322   IN  UINTN   *CurrentRow,
323   IN  BOOLEAN PrefixNewline
324   )
325 {
326   EFI_INPUT_KEY     InputKey;
327 
328   if (!gPageBreak) {
329     // global disable for this feature
330     return FALSE;
331   }
332 
333   if (*CurrentRow >= (gScreenRows - 2)) {
334     if (PrefixNewline) {
335       AsciiPrint ("\n");
336     }
337     AsciiPrint ("Any key to continue (Q to quit): ");
338     EblGetCharKey (&InputKey, 0, NULL);
339     AsciiPrint ("\n");
340 
341     // Time to promt to stop the screen. We have to leave space for the prompt string
342     *CurrentRow = 0;
343     if (InputKey.UnicodeChar == 'Q' || InputKey.UnicodeChar == 'q') {
344       return TRUE;
345     }
346   } else {
347     *CurrentRow += 1;
348   }
349 
350   return FALSE;
351 }
352 
353 
354 /**
355   Set the text color of the EFI Console. If a zero is passed in reset to
356   default text/background color.
357 
358   @param  Attribute   For text and background color
359 
360 **/
361 VOID
EblSetTextColor(UINTN Attribute)362 EblSetTextColor (
363   UINTN   Attribute
364   )
365 {
366   if (Attribute == 0) {
367     // Set the text color back to default
368     Attribute = (UINTN)PcdGet32 (PcdEmbeddedDefaultTextColor);
369   }
370 
371   gST->ConOut->SetAttribute (gST->ConOut, Attribute);
372 }
373 
374 
375 /**
376   Collect the keyboard input for a cmd line. Carriage Return, New Line, or ESC
377   terminates the command line. You can edit the command line via left arrow,
378   delete and backspace and they all back up and erase the command line.
379   No edit of command line is possible without deletion at this time!
380   The up arrow and down arrow fill Cmd with information from the history
381   buffer.
382 
383   @param  Cmd         Command line to return
384   @param  CmdMaxSize  Maximum size of Cmd
385 
386   @return The Status of EblGetCharKey()
387 
388 **/
389 EFI_STATUS
GetCmd(IN OUT CHAR8 * Cmd,IN UINTN CmdMaxSize)390 GetCmd (
391   IN OUT  CHAR8   *Cmd,
392   IN      UINTN   CmdMaxSize
393   )
394 {
395   EFI_STATUS    Status;
396   UINTN         Index;
397   UINTN         Index2;
398   CHAR8         Char;
399   CHAR8         *History;
400   EFI_INPUT_KEY Key;
401 
402   for (Index = 0; Index < CmdMaxSize - 1;) {
403     Status = EblGetCharKey (&Key, 0, NULL);
404     if (EFI_ERROR (Status)) {
405       Cmd[Index] = '\0';
406       AsciiPrint ("\n");
407       return Status;
408     }
409 
410     Char = (CHAR8)Key.UnicodeChar;
411     if ((Char == '\n') || (Char == '\r') || (Char == 0x7f)) {
412       Cmd[Index] = '\0';
413       if (FixedPcdGetBool(PcdEmbeddedShellCharacterEcho) == TRUE) {
414         AsciiPrint ("\n\r");
415       }
416       return EFI_SUCCESS;
417     } else if ((Char == '\b') || (Key.ScanCode == SCAN_LEFT) || (Key.ScanCode == SCAN_DELETE)){
418       if (Index != 0) {
419         Index--;
420         //
421         // Update the display
422         //
423         AsciiPrint ("\b \b");
424       }
425     } else if ((Key.ScanCode == SCAN_UP) || Key.ScanCode == SCAN_DOWN) {
426       History = GetCmdHistory (Key.ScanCode);
427       //
428       // Clear display line
429       //
430       for (Index2 = 0; Index2 < Index; Index2++) {
431         AsciiPrint ("\b \b");
432       }
433       AsciiPrint (History);
434       Index = AsciiStrLen (History);
435       AsciiStrnCpyS (Cmd, CmdMaxSize, History, CmdMaxSize);
436     } else {
437       Cmd[Index++] = Char;
438       if (FixedPcdGetBool(PcdEmbeddedShellCharacterEcho) == TRUE) {
439         AsciiPrint ("%c", Char);
440       }
441     }
442   }
443 
444   return EFI_SUCCESS;
445 }
446 
447 
448 /**
449   Print the boot up banner for the EBL.
450 **/
451 VOID
EblPrintStartupBanner(VOID)452 EblPrintStartupBanner (
453   VOID
454   )
455 {
456   AsciiPrint ("Embedded Boot Loader (");
457   EblSetTextColor (EFI_YELLOW);
458   AsciiPrint ("EBL");
459   EblSetTextColor (0);
460   AsciiPrint (") prototype. Built at %a on %a\n",__TIME__, __DATE__);
461   AsciiPrint ("THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN 'AS IS' BASIS,\nWITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\n");
462   AsciiPrint ("Please send feedback to edk2-devel@lists.sourceforge.net\n");
463 }
464 
465 
466 /**
467   Send null requests to all removable media block IO devices so the a media add/remove/change
468   can be detected in real before we execute a command.
469 
470   This is mainly due to the fact that the FAT driver does not do this today so you can get stale
471   dir commands after an SD Card has been removed.
472 **/
473 VOID
EblProbeRemovableMedia(VOID)474 EblProbeRemovableMedia (
475   VOID
476   )
477 {
478   UINTN         Index;
479   UINTN         Max;
480   EFI_OPEN_FILE *File;
481 
482   //
483   // Probe for media insertion/removal in removable media devices
484   //
485   Max = EfiGetDeviceCounts (EfiOpenBlockIo);
486   if (Max != 0) {
487     for (Index = 0; Index < Max; Index++) {
488       File = EfiDeviceOpenByType (EfiOpenBlockIo, Index);
489       if (File != NULL) {
490         if (File->FsBlockIoMedia->RemovableMedia) {
491           // Probe to see if media is present (or not) or media changed
492           //  this causes the ReinstallProtocolInterface() to fire in the
493           //  block io driver to update the system about media change events
494           File->FsBlockIo->ReadBlocks (File->FsBlockIo, File->FsBlockIo->Media->MediaId, (EFI_LBA)0, 0, NULL);
495         }
496         EfiClose (File);
497       }
498     }
499   }
500 }
501 
502 
503 
504 
505 /**
506   Print the prompt for the EBL.
507 **/
508 VOID
EblPrompt(VOID)509 EblPrompt (
510   VOID
511   )
512 {
513   EblSetTextColor (EFI_YELLOW);
514   AsciiPrint ("%a %a",(CHAR8 *)PcdGetPtr (PcdEmbeddedPrompt), EfiGetCwd ());
515   EblSetTextColor (0);
516   AsciiPrint ("%a", ">");
517 }
518 
519 
520 
521 /**
522   Parse a command line and execute the commands. The ; separator allows
523   multiple commands for each command line. Stop processing if one of the
524   commands returns an error.
525 
526   @param  CmdLine          Command Line to process.
527   @param  MaxCmdLineSize   MaxSize of the Command line
528 
529   @return EFI status of the Command
530 
531 **/
532 EFI_STATUS
ProcessCmdLine(IN CHAR8 * CmdLine,IN UINTN MaxCmdLineSize)533 ProcessCmdLine (
534   IN CHAR8      *CmdLine,
535   IN UINTN      MaxCmdLineSize
536   )
537 {
538   EFI_STATUS          Status;
539   EBL_COMMAND_TABLE   *Cmd;
540   CHAR8               *Ptr;
541   UINTN               Argc;
542   CHAR8               *Argv[MAX_ARGS];
543 
544   // Parse the command line. The loop processes commands separated by ;
545   for (Ptr = CmdLine, Status = EFI_SUCCESS; Ptr != NULL;) {
546     Ptr = ParseArguments (Ptr, &Argc, Argv);
547     if (Argc != 0) {
548       Cmd = EblGetCommand (Argv[0]);
549       if (Cmd != NULL) {
550         // Execute the Command!
551         Status = Cmd->Command (Argc, Argv);
552         if (Status == EFI_ABORTED) {
553           // exit command so lets exit
554           break;
555         } else if (Status == EFI_TIMEOUT) {
556           // pause command got input so don't process any more cmd on this cmd line
557           break;
558         } else if (EFI_ERROR (Status)) {
559           AsciiPrint ("%a returned %r error\n", Cmd->Name, Status);
560           // if any command fails stop processing CmdLine
561           break;
562         }
563       } else {
564         AsciiPrint ("The command '%a' is not supported.\n", Argv[0]);
565       }
566     }
567   }
568 
569   return Status;
570 }
571 
572 
573 
574 /**
575   Embedded Boot Loader (EBL) - A simple EFI command line application for embedded
576   devices. PcdEmbeddedAutomaticBootCommand is a complied in command line that
577   gets executed automatically. The ; separator allows multiple commands
578   for each command line.
579 
580   @param  ImageHandle   EFI ImageHandle for this application.
581   @param  SystemTable   EFI system table
582 
583   @return EFI status of the application
584 
585 **/
586 EFI_STATUS
587 EFIAPI
EdkBootLoaderEntry(IN EFI_HANDLE ImageHandle,IN EFI_SYSTEM_TABLE * SystemTable)588 EdkBootLoaderEntry (
589   IN EFI_HANDLE                            ImageHandle,
590   IN EFI_SYSTEM_TABLE                      *SystemTable
591   )
592 {
593   EFI_STATUS  Status;
594   CHAR8       CmdLine[MAX_CMD_LINE];
595   CHAR16      *CommandLineVariable = NULL;
596   CHAR16      *CommandLineVariableName = L"default-cmdline";
597   UINTN       CommandLineVariableSize = 0;
598   EFI_GUID    VendorGuid;
599 
600   // Initialize tables of commands
601   EblInitializeCmdTable ();
602   EblInitializeDeviceCmd ();
603   EblInitializemdHwDebugCmds ();
604   EblInitializemdHwIoDebugCmds ();
605   EblInitializeDirCmd ();
606   EblInitializeHobCmd ();
607   EblInitializeScriptCmd ();
608   EblInitializeExternalCmd ();
609   EblInitializeNetworkCmd();
610   EblInitializeVariableCmds ();
611 
612   if (gST->ConOut == NULL) {
613     DEBUG((EFI_D_ERROR,"Error: No Console Output\n"));
614     return EFI_NOT_READY;
615   }
616 
617   // Disable the 5 minute EFI watchdog time so we don't get automatically reset
618   gBS->SetWatchdogTimer (0, 0, 0, NULL);
619 
620   if (FeaturePcdGet (PcdEmbeddedMacBoot)) {
621     // A MAC will boot in graphics mode, so turn it back to text here
622     // This protocol was removed from edk2. It is only an edk thing. We need to make our own copy.
623     // DisableQuietBoot ();
624 
625     // Enable the biggest output screen size possible
626     gST->ConOut->SetMode (gST->ConOut, (UINTN)gST->ConOut->Mode->MaxMode - 1);
627 
628   }
629 
630   // Save current screen mode
631   gST->ConOut->QueryMode (gST->ConOut, gST->ConOut->Mode->Mode, &gScreenColumns, &gScreenRows);
632 
633   EblPrintStartupBanner ();
634 
635   // Parse command line and handle commands separated by ;
636   // The loop prints the prompt gets user input and saves history
637 
638   // Look for a variable with a default command line, otherwise use the Pcd
639   ZeroMem(&VendorGuid, sizeof(EFI_GUID));
640 
641   Status = gRT->GetVariable(CommandLineVariableName, &VendorGuid, NULL, &CommandLineVariableSize, CommandLineVariable);
642   if (Status == EFI_BUFFER_TOO_SMALL) {
643     CommandLineVariable = AllocatePool(CommandLineVariableSize);
644 
645     Status = gRT->GetVariable(CommandLineVariableName, &VendorGuid, NULL, &CommandLineVariableSize, CommandLineVariable);
646     if (!EFI_ERROR(Status)) {
647       UnicodeStrToAsciiStrS (CommandLineVariable, CmdLine, MAX_CMD_LINE);
648     }
649 
650     FreePool(CommandLineVariable);
651   }
652 
653   if (EFI_ERROR(Status)) {
654     AsciiStrCpyS (CmdLine, MAX_CMD_LINE, (CHAR8 *)PcdGetPtr (PcdEmbeddedAutomaticBootCommand));
655   }
656 
657   for (;;) {
658     Status = ProcessCmdLine (CmdLine, MAX_CMD_LINE);
659     if (Status == EFI_ABORTED) {
660       // if a command returns EFI_ABORTED then exit the EBL
661       EblShutdownExternalCmdTable ();
662       return EFI_SUCCESS;
663     }
664 
665     // get the command line from the user
666     EblPrompt ();
667     GetCmd (CmdLine, MAX_CMD_LINE);
668     SetCmdHistory (CmdLine);
669 
670     if (FeaturePcdGet (PcdEmbeddedProbeRemovable)) {
671       // Probe removable media devices to see if media has been inserted or removed.
672       EblProbeRemovableMedia ();
673     }
674   }
675 }
676 
677 
678