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ArmPkg/BdsLib: Linux kernel supports either FDT or ATAG
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1 /** @file
2 *
3 * Copyright (c) 2011, ARM Limited. All rights reserved.
4 *
5 * This program and the accompanying materials
6 * are licensed and made available under the terms and conditions of the BSD License
7 * which accompanies this distribution. The full text of the license may be found at
8 * http://opensource.org/licenses/bsd-license.php
9 *
10 * THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
12 *
13 **/
14
15 #include "BdsInternal.h"
16 #include "BdsLinuxLoader.h"
17
18 #include <Library/PcdLib.h>
19 #include <Library/ArmLib.h>
20 #include <Library/HobLib.h>
21
22 #define ALIGN32_BELOW(addr) ALIGN_POINTER(addr - 32,32)
23
24 #define LINUX_ATAG_MAX_OFFSET (PcdGet32(PcdSystemMemoryBase) + PcdGet32(PcdArmLinuxAtagMaxOffset))
25 #define LINUX_KERNEL_MAX_OFFSET (PcdGet32(PcdSystemMemoryBase) + PcdGet32(PcdArmLinuxKernelMaxOffset))
26
27 // Point to the current ATAG
28 STATIC LINUX_ATAG *mLinuxKernelCurrentAtag;
29
30 STATIC
31 VOID
32 SetupCoreTag (
33 IN UINT32 PageSize
34 )
35 {
36 mLinuxKernelCurrentAtag->header.size = tag_size(LINUX_ATAG_CORE);
37 mLinuxKernelCurrentAtag->header.type = ATAG_CORE;
38
39 mLinuxKernelCurrentAtag->body.core_tag.flags = 1; /* ensure read-only */
40 mLinuxKernelCurrentAtag->body.core_tag.pagesize = PageSize; /* systems PageSize (4k) */
41 mLinuxKernelCurrentAtag->body.core_tag.rootdev = 0; /* zero root device (typically overridden from kernel command line )*/
42
43 // move pointer to next tag
44 mLinuxKernelCurrentAtag = next_tag_address(mLinuxKernelCurrentAtag);
45 }
46
47 STATIC
48 VOID
49 SetupMemTag (
50 IN UINTN StartAddress,
51 IN UINT32 Size
52 )
53 {
54 mLinuxKernelCurrentAtag->header.size = tag_size(LINUX_ATAG_MEM);
55 mLinuxKernelCurrentAtag->header.type = ATAG_MEM;
56
57 mLinuxKernelCurrentAtag->body.mem_tag.start = StartAddress; /* Start of memory chunk for AtagMem */
58 mLinuxKernelCurrentAtag->body.mem_tag.size = Size; /* Size of memory chunk for AtagMem */
59
60 // move pointer to next tag
61 mLinuxKernelCurrentAtag = next_tag_address(mLinuxKernelCurrentAtag);
62 }
63
64 STATIC
65 VOID
66 SetupCmdlineTag (
67 IN CONST CHAR8 *CmdLine
68 )
69 {
70 UINT32 LineLength;
71
72 // Increment the line length by 1 to account for the null string terminator character
73 LineLength = AsciiStrLen(CmdLine) + 1;
74
75 /* Check for NULL strings.
76 * Do not insert a tag for an empty CommandLine, don't even modify the tag address pointer.
77 * Remember, you have at least one null string terminator character.
78 */
79 if(LineLength > 1) {
80 mLinuxKernelCurrentAtag->header.size = ((UINT32)sizeof(LINUX_ATAG_HEADER) + LineLength + (UINT32)3) >> 2;
81 mLinuxKernelCurrentAtag->header.type = ATAG_CMDLINE;
82
83 /* place CommandLine into tag */
84 AsciiStrCpy(mLinuxKernelCurrentAtag->body.cmdline_tag.cmdline, CmdLine);
85
86 // move pointer to next tag
87 mLinuxKernelCurrentAtag = next_tag_address(mLinuxKernelCurrentAtag);
88 }
89 }
90
91 STATIC
92 VOID
93 SetupEndTag (
94 VOID
95 )
96 {
97 // Empty tag ends list; this has zero length and no body
98 mLinuxKernelCurrentAtag->header.type = ATAG_NONE;
99 mLinuxKernelCurrentAtag->header.size = 0;
100
101 /* We can not calculate the next address by using the standard macro:
102 * Params = next_tag_address(Params);
103 * because it relies on the header.size, which here it is 0 (zero).
104 * The easiest way is to add the sizeof(mLinuxKernelCurrentAtag->header).
105 */
106 mLinuxKernelCurrentAtag = (LINUX_ATAG*)((UINT32)mLinuxKernelCurrentAtag + sizeof(mLinuxKernelCurrentAtag->header));
107 }
108
109 STATIC
110 EFI_STATUS
111 PrepareAtagList (
112 IN CONST CHAR8* CommandLineString,
113 OUT LINUX_ATAG **AtagBase,
114 OUT UINT32 *AtagSize
115 )
116 {
117 EFI_STATUS Status;
118 LIST_ENTRY *ResourceLink;
119 LIST_ENTRY ResourceList;
120 EFI_PHYSICAL_ADDRESS AtagStartAddress;
121 BDS_SYSTEM_MEMORY_RESOURCE *Resource;
122
123 AtagStartAddress = LINUX_ATAG_MAX_OFFSET;
124 Status = gBS->AllocatePages (AllocateMaxAddress, EfiBootServicesData, EFI_SIZE_TO_PAGES(ATAG_MAX_SIZE), &AtagStartAddress);
125 if (EFI_ERROR(Status)) {
126 DEBUG ((EFI_D_ERROR,"Failed to allocate Atag at 0x%lX (%r)\n",AtagStartAddress,Status));
127 Status = gBS->AllocatePages (AllocateAnyPages, EfiBootServicesData, EFI_SIZE_TO_PAGES(ATAG_MAX_SIZE), &AtagStartAddress);
128 ASSERT_EFI_ERROR(Status);
129 }
130
131 // Ready to setup the atag list
132 mLinuxKernelCurrentAtag = (LINUX_ATAG*)(UINTN)AtagStartAddress;
133
134 // Standard core tag 4k PageSize
135 SetupCoreTag( (UINT32)SIZE_4KB );
136
137 // Physical memory setup
138 GetSystemMemoryResources (&ResourceList);
139 ResourceLink = ResourceList.ForwardLink;
140 while (ResourceLink != NULL && ResourceLink != &ResourceList) {
141 Resource = (BDS_SYSTEM_MEMORY_RESOURCE*)ResourceLink;
142 DEBUG((EFI_D_INFO,"- [0x%08X,0x%08X]\n",(UINT32)Resource->PhysicalStart,(UINT32)Resource->PhysicalStart+(UINT32)Resource->ResourceLength));
143 SetupMemTag( (UINT32)Resource->PhysicalStart, (UINT32)Resource->ResourceLength );
144 ResourceLink = ResourceLink->ForwardLink;
145 }
146
147 // CommandLine setting root device
148 SetupCmdlineTag (CommandLineString);
149
150 // end of tags
151 SetupEndTag();
152
153 // Calculate atag list size
154 *AtagBase = (LINUX_ATAG*)(UINTN)AtagStartAddress;
155 *AtagSize = (UINT32)mLinuxKernelCurrentAtag - (UINT32)AtagStartAddress + 1;
156
157 return EFI_SUCCESS;
158 }
159
160 STATIC
161 EFI_STATUS
162 PreparePlatformHardware (
163 VOID
164 )
165 {
166 //Note: Interrupts will be disabled by the GIC driver when ExitBootServices() will be called.
167
168 // clean, invalidate, disable data cache
169 ArmCleanInvalidateDataCache();
170 ArmDisableDataCache();
171
172 // Invalidate and disable the Instruction cache
173 ArmInvalidateInstructionCache ();
174 ArmDisableInstructionCache ();
175
176 // turn off MMU
177 ArmDisableMmu();
178
179 return EFI_SUCCESS;
180 }
181
182 /**
183 Start a Linux kernel from a Device Path
184
185 @param LinuxKernel Device Path to the Linux Kernel
186 @param Parameters Linux kernel agruments
187 @param Fdt Device Path to the Flat Device Tree
188
189 @retval EFI_SUCCESS All drivers have been connected
190 @retval EFI_NOT_FOUND The Linux kernel Device Path has not been found
191 @retval EFI_OUT_OF_RESOURCES There is not enough resource memory to store the matching results.
192
193 **/
194 EFI_STATUS
195 BdsBootLinux (
196 IN EFI_DEVICE_PATH_PROTOCOL* LinuxKernelDevicePath,
197 IN CONST CHAR8* Arguments,
198 IN EFI_DEVICE_PATH_PROTOCOL* FdtDevicePath
199 )
200 {
201 EFI_STATUS Status;
202 UINT32 LinuxImageSize;
203 UINT32 KernelParamsSize;
204 EFI_PHYSICAL_ADDRESS KernelParamsAddress;
205 UINT32 MachineType;
206 BOOLEAN FdtSupported = FALSE;
207 LINUX_KERNEL LinuxKernel;
208 EFI_PHYSICAL_ADDRESS LinuxImage;;
209
210
211 PERF_START (NULL, "BDS", NULL, 0);
212
213 // Load the Linux kernel from a device path
214 LinuxImage = LINUX_KERNEL_MAX_OFFSET;
215 Status = BdsLoadImage (LinuxKernelDevicePath, AllocateMaxAddress, &LinuxImage, &LinuxImageSize);
216 if (EFI_ERROR(Status)) {
217 Print (L"ERROR: Did not find Linux kernel.\n");
218 return Status;
219 }
220 LinuxKernel = (LINUX_KERNEL)(UINTN)LinuxImage;
221
222 if (FdtDevicePath) {
223 // Load the FDT binary from a device path
224 KernelParamsAddress = LINUX_ATAG_MAX_OFFSET;
225 Status = BdsLoadImage (FdtDevicePath, AllocateMaxAddress, &KernelParamsAddress, &KernelParamsSize);
226 if (EFI_ERROR(Status)) {
227 Print (L"ERROR: Did not find Device Tree blob.\n");
228 return Status;
229 }
230 FdtSupported = TRUE;
231 }
232
233 //
234 // Setup the Linux Kernel Parameters
235 //
236 if (!FdtSupported) {
237 // Non-FDT requires a specific machine type.
238 // This OS Boot loader supports just one machine type,
239 // but that could change in the future.
240 MachineType = PcdGet32(PcdArmMachineType);
241
242 // By setting address=0 we leave the memory allocation to the function
243 Status = PrepareAtagList (Arguments, (LINUX_ATAG**)&KernelParamsAddress, &KernelParamsSize);
244 if(EFI_ERROR(Status)) {
245 Print(L"ERROR: Can not prepare ATAG list. Status=0x%X\n", Status);
246 goto Exit;
247 }
248 } else {
249 MachineType = 0xFFFFFFFF;
250 }
251
252 // Shut down UEFI boot services. ExitBootServices() will notify every driver that created an event on
253 // ExitBootServices event. Example the Interrupt DXE driver will disable the interrupts on this event.
254 Status = ShutdownUefiBootServices ();
255 if(EFI_ERROR(Status)) {
256 DEBUG((EFI_D_ERROR,"ERROR: Can not shutdown UEFI boot services. Status=0x%X\n", Status));
257 goto Exit;
258 }
259
260 // Move the kernel parameters to any address inside the first 1MB.
261 // This is necessary because the ARM Linux kernel requires
262 // the FTD / ATAG List to reside entirely inside the first 1MB of
263 // physical memory.
264 if ((UINTN)KernelParamsAddress > LINUX_ATAG_MAX_OFFSET) {
265 //Note: There is no requirement on the alignment
266 KernelParamsAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)CopyMem (ALIGN32_BELOW(LINUX_ATAG_MAX_OFFSET - KernelParamsSize), (VOID*)(UINTN)KernelParamsAddress, KernelParamsSize);
267 }
268
269 if ((UINTN)LinuxImage > LINUX_KERNEL_MAX_OFFSET) {
270 //Note: There is no requirement on the alignment
271 LinuxKernel = (LINUX_KERNEL)CopyMem (ALIGN32_BELOW(LINUX_KERNEL_MAX_OFFSET - LinuxImageSize), (VOID*)(UINTN)LinuxImage, LinuxImageSize);
272 }
273
274 //TODO: Check there is no overlapping between kernel and Atag
275
276 //
277 // Switch off interrupts, caches, mmu, etc
278 //
279 Status = PreparePlatformHardware ();
280 ASSERT_EFI_ERROR(Status);
281
282 // Register and print out performance information
283 PERF_END (NULL, "BDS", NULL, 0);
284 if (PerformanceMeasurementEnabled ()) {
285 PrintPerformance ();
286 }
287
288 //
289 // Start the Linux Kernel
290 //
291
292 // Outside BootServices, so can't use Print();
293 DEBUG((EFI_D_ERROR, "\nStarting the kernel:\n\n"));
294
295 // jump to kernel with register set
296 LinuxKernel ((UINTN)0, (UINTN)MachineType, (UINTN)KernelParamsAddress);
297
298 // Kernel should never exit
299 // After Life services are not provided
300 ASSERT(FALSE);
301
302 Exit:
303 // Only be here if we fail to start Linux
304 Print (L"ERROR : Can not start the kernel. Status=0x%X\n", Status);
305
306 // Free Runtimee Memory (kernel and FDT)
307 return Status;
308 }