// https://blog.fpmurphy.com/2015/01/list-acpi-tables-from-uefi-shell.html
// Copyright (c) 2015  Finnbarr P. Murphy. All rights reserved.
// Display list of ACPI tables 
// License: BSD License

#include <efi.h>
#include <efilib.h>
#include "listacpi.h"

UINTN
myStrnCmpA(CHAR8* s1, CHAR8* s2, UINTN len)
{
    while (*s1 && len) {
        if (*s1 != *s2) {
            break;
        }
        s1 += 1;
        s2 += 1;
        len -= 1;
    }

    return len ? *s1 - *s2 : 0;
}


VOID
Ascii2UnicodeStr(CHAR8* String, CHAR16* UniString, UINT8 length)
{
    int len = length;

    while (*String != '\0' && len > 0) {
        *(UniString++) = (CHAR16) * (String++);
        len--;
    }
    *UniString = '\0';
}


int
ParseRSDP(EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER* Rsdp, CHAR16* GuidStr)
{
    EFI_ACPI_SDT_HEADER* Xsdt, * Entry;
    CHAR16 SigStr[20], OemStr[20];
    UINT32 EntryCount;
    UINT64* EntryPtr;
    int Index;

    Print(L"\n\nACPI GUID: %s\n", GuidStr);
    Ascii2UnicodeStr((CHAR8*)(Rsdp->OemId), OemStr, 6);
    Print(L"\nFound RSDP. Version: %d  OEM ID: %s\n", (int)(Rsdp->Revision), OemStr);

    if (Rsdp->Revision >= EFI_ACPI_2_0_ROOT_SYSTEM_DESCRIPTION_POINTER_REVISION) {
        Xsdt = (EFI_ACPI_SDT_HEADER*)(Rsdp->XsdtAddress);
    }
    else {
        Print(L"ERROR: No XSDT table found.\n");
        return 1;
    }

    if (myStrnCmpA("XSDT", (CHAR8*)(VOID*)(Xsdt->Signature), 4)) {
        Print(L"ERROR: Invalid XSDT table found.\n");
        return 1;
    }

    Ascii2UnicodeStr((CHAR8*)(Xsdt->OemId), OemStr, 6);
    EntryCount = (Xsdt->Length - sizeof(EFI_ACPI_SDT_HEADER)) / sizeof(UINT64);
    Print(L"Found XSDT. OEM ID: %s  Entry Count: %d\n\n", OemStr, EntryCount);

    EntryPtr = (UINT64*)(Xsdt + 1);
    for (Index = 0; Index < EntryCount; Index++, EntryPtr++) {
        Entry = (EFI_ACPI_SDT_HEADER*)((UINTN)(*EntryPtr));
        Ascii2UnicodeStr((CHAR8*)(Entry->Signature), SigStr, 4);
        Ascii2UnicodeStr((CHAR8*)(Entry->OemId), OemStr, 6);
        Print(L"Found ACPI table: %s  Version: %d  OEM ID: %s\n", SigStr, (int)(Entry->Revision), OemStr);
    }

    return 0;
}


VOID
Guid2String(CHAR16* Buffer, EFI_GUID* Guid)
{
    SPrint(Buffer, 0, L"%08x-%04x-%04x-%02x%02x-%02x%02x%02x%02x%02x%02x",
        Guid->Data1,
        Guid->Data2,
        Guid->Data3,
        Guid->Data4[0],
        Guid->Data4[1],
        Guid->Data4[2],
        Guid->Data4[3],
        Guid->Data4[4],
        Guid->Data4[5],
        Guid->Data4[6],
        Guid->Data4[7]);
}