diff options
-rw-r--r-- | UefiCpuPkg/CpuMpPei/CpuMpPei.c | 71 | ||||
-rw-r--r-- | UefiCpuPkg/CpuMpPei/CpuMpPei.h | 1 | ||||
-rw-r--r-- | UefiCpuPkg/CpuMpPei/CpuMpPei.inf | 1 |
3 files changed, 73 insertions, 0 deletions
diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.c b/UefiCpuPkg/CpuMpPei/CpuMpPei.c index 78299b3271..0e34f26afc 100644 --- a/UefiCpuPkg/CpuMpPei/CpuMpPei.c +++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.c @@ -38,6 +38,77 @@ GLOBAL_REMOVE_IF_UNREFERENCED IA32_DESCRIPTOR mGdt = { (UINTN) mGdtEntries }; +/** + Get available system memory below 1MB by specified size. + + @param WakeupBufferSize Wakeup buffer size required + + @retval other Return wakeup buffer address below 1MB. + @retval -1 Cannot find free memory below 1MB. +**/ +UINTN +GetWakeupBuffer ( + IN UINTN WakeupBufferSize + ) +{ + EFI_PEI_HOB_POINTERS Hob; + UINTN WakeupBufferStart; + UINTN WakeupBufferEnd; + + // + // Get the HOB list for processing + // + Hob.Raw = GetHobList (); + + // + // Collect memory ranges + // + while (!END_OF_HOB_LIST (Hob)) { + if (Hob.Header->HobType == EFI_HOB_TYPE_RESOURCE_DESCRIPTOR) { + if ((Hob.ResourceDescriptor->PhysicalStart < BASE_1MB) && + (Hob.ResourceDescriptor->ResourceType == EFI_RESOURCE_SYSTEM_MEMORY) && + ((Hob.ResourceDescriptor->ResourceAttribute & + (EFI_RESOURCE_ATTRIBUTE_READ_PROTECTED | + EFI_RESOURCE_ATTRIBUTE_WRITE_PROTECTED | + EFI_RESOURCE_ATTRIBUTE_EXECUTION_PROTECTED + )) == 0) + ) { + // + // Need memory under 1MB to be collected here + // + WakeupBufferEnd = (UINTN) (Hob.ResourceDescriptor->PhysicalStart + Hob.ResourceDescriptor->ResourceLength); + if (WakeupBufferEnd > BASE_1MB) { + // + // Wakeup buffer should be under 1MB + // + WakeupBufferEnd = BASE_1MB; + } + // + // Wakeup buffer should be aligned on 4KB + // + WakeupBufferStart = (WakeupBufferEnd - WakeupBufferSize) & ~(SIZE_4KB - 1); + if (WakeupBufferStart < Hob.ResourceDescriptor->PhysicalStart) { + continue; + } + // + // Create a memory allocation HOB. + // + BuildMemoryAllocationHob ( + WakeupBufferStart, + WakeupBufferSize, + EfiBootServicesData + ); + return WakeupBufferStart; + } + } + // + // Find the next HOB + // + Hob.Raw = GET_NEXT_HOB (Hob); + } + + return (UINTN) -1; +} /** The Entry point of the MP CPU PEIM. diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.h b/UefiCpuPkg/CpuMpPei/CpuMpPei.h index 611a296dce..da01fdac87 100644 --- a/UefiCpuPkg/CpuMpPei/CpuMpPei.h +++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.h @@ -19,6 +19,7 @@ #include <Library/BaseLib.h> +#include <Library/HobLib.h> #include <Library/PeimEntryPoint.h> #pragma pack(1) diff --git a/UefiCpuPkg/CpuMpPei/CpuMpPei.inf b/UefiCpuPkg/CpuMpPei/CpuMpPei.inf index 1dfee4eac8..7cf33d3249 100644 --- a/UefiCpuPkg/CpuMpPei/CpuMpPei.inf +++ b/UefiCpuPkg/CpuMpPei/CpuMpPei.inf @@ -49,6 +49,7 @@ [LibraryClasses] BaseLib + HobLib PeimEntryPoint |