1 /** @file
2   Main routines for the EBC interpreter.  Includes the initialization and
3   main interpreter routines.
4 
5 Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
6 This program and the accompanying materials
7 are licensed and made available under the terms and conditions of the BSD License
8 which accompanies this distribution.  The full text of the license may be found at
9 http://opensource.org/licenses/bsd-license.php
10 
11 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
12 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
13 
14 **/
15 
16 #ifndef _EBC_INT_H_
17 #define _EBC_INT_H_
18 
19 
20 #include <Uefi.h>
21 
22 #include <Protocol/DebugSupport.h>
23 #include <Protocol/Ebc.h>
24 #include <Protocol/EbcVmTest.h>
25 #include <Protocol/EbcSimpleDebugger.h>
26 
27 #include <Library/BaseLib.h>
28 #include <Library/DebugLib.h>
29 #include <Library/UefiDriverEntryPoint.h>
30 #include <Library/BaseMemoryLib.h>
31 #include <Library/UefiBootServicesTableLib.h>
32 #include <Library/MemoryAllocationLib.h>
33 
34 extern VM_CONTEXT                    *mVmPtr;
35 
36 //
37 // Flags passed to the internal create-thunks function.
38 //
39 #define FLAG_THUNK_ENTRY_POINT  0x01  // thunk for an image entry point
40 #define FLAG_THUNK_PROTOCOL     0x00  // thunk for an EBC protocol service
41 //
42 // Put this value at the bottom of the VM's stack gap so we can check it on
43 // occasion to make sure the stack has not been corrupted.
44 //
45 #define VM_STACK_KEY_VALUE  0xDEADBEEF
46 
47 /**
48   Create thunks for an EBC image entry point, or an EBC protocol service.
49 
50   @param  ImageHandle           Image handle for the EBC image. If not null, then
51                                 we're creating a thunk for an image entry point.
52   @param  EbcEntryPoint         Address of the EBC code that the thunk is to call
53   @param  Thunk                 Returned thunk we create here
54   @param  Flags                 Flags indicating options for creating the thunk
55 
56   @retval EFI_SUCCESS           The thunk was created successfully.
57   @retval EFI_INVALID_PARAMETER The parameter of EbcEntryPoint is not 16-bit
58                                 aligned.
59   @retval EFI_OUT_OF_RESOURCES  There is not enough memory to created the EBC
60                                 Thunk.
61   @retval EFI_BUFFER_TOO_SMALL  EBC_THUNK_SIZE is not larger enough.
62 
63 **/
64 EFI_STATUS
65 EbcCreateThunks (
66   IN EFI_HANDLE           ImageHandle,
67   IN VOID                 *EbcEntryPoint,
68   OUT VOID                **Thunk,
69   IN  UINT32              Flags
70   );
71 
72 /**
73   Add a thunk to our list of thunks for a given image handle.
74   Also flush the instruction cache since we've written thunk code
75   to memory that will be executed eventually.
76 
77   @param  ImageHandle            The image handle to which the thunk is tied.
78   @param  ThunkBuffer            The buffer that has been created/allocated.
79   @param  ThunkSize              The size of the thunk memory allocated.
80 
81   @retval EFI_OUT_OF_RESOURCES   Memory allocation failed.
82   @retval EFI_SUCCESS            The function completed successfully.
83 
84 **/
85 EFI_STATUS
86 EbcAddImageThunk (
87   IN EFI_HANDLE      ImageHandle,
88   IN VOID            *ThunkBuffer,
89   IN UINT32          ThunkSize
90   );
91 
92 //
93 // Define a constant of how often to call the debugger periodic callback
94 // function.
95 //
96 #define EFI_TIMER_UNIT_1MS            (1000 * 10)
97 #define EBC_VM_PERIODIC_CALLBACK_RATE (1000 * EFI_TIMER_UNIT_1MS)
98 #define STACK_POOL_SIZE               (1024 * 1020)
99 #define MAX_STACK_NUM                 4
100 
101 //
102 // External low level functions that are native-processor dependent
103 //
104 /**
105   The VM thunk code stuffs an EBC entry point into a processor
106   register. Since we can't use inline assembly to get it from
107   the interpreter C code, stuff it into the return value
108   register and return.
109 
110   @return  The contents of the register in which the entry point is passed.
111 
112 **/
113 UINTN
114 EFIAPI
115 EbcLLGetEbcEntryPoint (
116   VOID
117   );
118 
119 /**
120   This function is called to execute an EBC CALLEX instruction.
121   This instruction requires that we thunk out to external native
122   code. For x64, we switch stacks, copy the arguments to the stack
123   and jump to the specified function.
124   On return, we restore the stack pointer to its original location.
125   Destroys no working registers.
126 
127   @param  CallAddr     The function address.
128   @param  EbcSp        The new EBC stack pointer.
129   @param  FramePtr     The frame pointer.
130 
131   @return The unmodified value returned by the native code.
132 
133 **/
134 INT64
135 EFIAPI
136 EbcLLCALLEXNative (
137   IN UINTN        CallAddr,
138   IN UINTN        EbcSp,
139   IN VOID         *FramePtr
140   );
141 
142 /**
143   This function is called to execute an EBC CALLEX instruction.
144   The function check the callee's content to see whether it is common native
145   code or a thunk to another piece of EBC code.
146   If the callee is common native code, use EbcLLCAllEXASM to manipulate,
147   otherwise, set the VM->IP to target EBC code directly to avoid another VM
148   be startup which cost time and stack space.
149 
150   @param  VmPtr            Pointer to a VM context.
151   @param  FuncAddr         Callee's address
152   @param  NewStackPointer  New stack pointer after the call
153   @param  FramePtr         New frame pointer after the call
154   @param  Size             The size of call instruction
155 
156 **/
157 VOID
158 EbcLLCALLEX (
159   IN VM_CONTEXT   *VmPtr,
160   IN UINTN        FuncAddr,
161   IN UINTN        NewStackPointer,
162   IN VOID         *FramePtr,
163   IN UINT8        Size
164   );
165 
166 /**
167   Returns the stack index and buffer assosicated with the Handle parameter.
168 
169   @param  Handle                The EFI handle as the index to the EBC stack.
170   @param  StackBuffer           A pointer to hold the returned stack buffer.
171   @param  BufferIndex           A pointer to hold the returned stack index.
172 
173   @retval EFI_OUT_OF_RESOURCES  The Handle parameter does not correspond to any
174                                 existing EBC stack.
175   @retval EFI_SUCCESS           The stack index and buffer were found and
176                                 returned to the caller.
177 
178 **/
179 EFI_STATUS
180 GetEBCStack(
181   IN  EFI_HANDLE Handle,
182   OUT VOID       **StackBuffer,
183   OUT UINTN      *BufferIndex
184   );
185 
186 /**
187   Returns from the EBC stack by stack Index.
188 
189   @param  Index        Specifies which EBC stack to return from.
190 
191   @retval EFI_SUCCESS  The function completed successfully.
192 
193 **/
194 EFI_STATUS
195 ReturnEBCStack(
196   IN UINTN Index
197   );
198 
199 /**
200   Allocates memory to hold all the EBC stacks.
201 
202   @retval EFI_SUCCESS          The EBC stacks were allocated successfully.
203   @retval EFI_OUT_OF_RESOURCES Not enough memory available for EBC stacks.
204 
205 **/
206 EFI_STATUS
207 InitEBCStack (
208   VOID
209   );
210 
211 /**
212   Free all EBC stacks allocated before.
213 
214   @retval EFI_SUCCESS   All the EBC stacks were freed.
215 
216 **/
217 EFI_STATUS
218 FreeEBCStack(
219   VOID
220   );
221 
222 /**
223   Returns from the EBC stack associated with the Handle parameter.
224 
225   @param  Handle      Specifies the EFI handle to find the EBC stack with.
226 
227   @retval EFI_SUCCESS The function completed successfully.
228 
229 **/
230 EFI_STATUS
231 ReturnEBCStackByHandle(
232   IN EFI_HANDLE Handle
233   );
234 
235 typedef struct {
236   EFI_EBC_PROTOCOL  *This;
237   VOID              *EntryPoint;
238   EFI_HANDLE        ImageHandle;
239   VM_CONTEXT        VmContext;
240 } EFI_EBC_THUNK_DATA;
241 
242 #define EBC_PROTOCOL_PRIVATE_DATA_SIGNATURE SIGNATURE_32 ('e', 'b', 'c', 'p')
243 
244 
245 #define EBC_PROTOCOL_PRIVATE_DATA_FROM_THIS(a) \
246       CR(a, EBC_PROTOCOL_PRIVATE_DATA, EbcProtocol, EBC_PROTOCOL_PRIVATE_DATA_SIGNATURE)
247 
248 
249 #endif // #ifndef _EBC_INT_H_
250