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| author | Pierre Gondois <Pierre.Gondois@arm.com> | 2021-09-30 08:48:16 +0100 |
|---|---|---|
| committer | mergify[bot] <37929162+mergify[bot]@users.noreply.github.com> | 2021-10-01 10:57:43 +0000 |
| commit | 72ab55255478a8c87f670e12d9e4475279759137 (patch) | |
| tree | 0a52b6a34dd3640f659b219eb6345e6246f532fe /DynamicTablesPkg | |
| parent | 653113412fe1099bc80bc128f6501ea77631cc0e (diff) | |
| download | edk2-72ab55255478a8c87f670e12d9e4475279759137.zip edk2-72ab55255478a8c87f670e12d9e4475279759137.tar.gz edk2-72ab55255478a8c87f670e12d9e4475279759137.tar.bz2 | |
DynamicTablesPkg: Add AmlGetEisaIdFromString() to AcpiHelperLib
Add a function converting a 7 characters string to its UINT32
EISAID. The algorithm used to create the EISAID is described
in the ACPI 6.4 specification, s19.3.4 "ASL Macros".
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Pierre Gondois <Pierre.Gondois@arm.com>
Diffstat (limited to 'DynamicTablesPkg')
| -rw-r--r-- | DynamicTablesPkg/Include/Library/AcpiHelperLib.h | 17 | ||||
| -rw-r--r-- | DynamicTablesPkg/Library/Common/AcpiHelperLib/AcpiHelper.c | 69 |
2 files changed, 86 insertions, 0 deletions
diff --git a/DynamicTablesPkg/Include/Library/AcpiHelperLib.h b/DynamicTablesPkg/Include/Library/AcpiHelperLib.h index 094392a..a93e95e 100644 --- a/DynamicTablesPkg/Include/Library/AcpiHelperLib.h +++ b/DynamicTablesPkg/Include/Library/AcpiHelperLib.h @@ -73,4 +73,21 @@ IsValidAcpiId ( IN CONST CHAR8 * Hid
);
+/** Convert a EisaId string to its compressed UINT32 equivalent.
+
+ Cf. ACPI 6.4 specification, s19.3.4 "ASL Macros": "Eisaid"
+
+ @param [in] EisaIdStr Input EisaId string.
+ @param [out] EisaIdInt Output EisaId UINT32 (compressed).
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlGetEisaIdFromString (
+ IN CONST CHAR8 * EisaIdStr,
+ OUT UINT32 * EisaIdInt
+ );
+
#endif // ACPI_HELPER_LIB_H_
diff --git a/DynamicTablesPkg/Library/Common/AcpiHelperLib/AcpiHelper.c b/DynamicTablesPkg/Library/Common/AcpiHelperLib/AcpiHelper.c index 0b566f0..5afd257 100644 --- a/DynamicTablesPkg/Library/Common/AcpiHelperLib/AcpiHelper.c +++ b/DynamicTablesPkg/Library/Common/AcpiHelperLib/AcpiHelper.c @@ -139,3 +139,72 @@ IsValidAcpiId ( return TRUE;
}
+
+/** Convert a EisaId string to its compressed UINT32 equivalent.
+
+ Cf. ACPI 6.4 specification, s19.3.4 "ASL Macros": "Eisaid"
+
+ @param [in] EisaIdStr Input EisaId string.
+ @param [out] EisaIdInt Output EisaId UINT32 (compressed).
+
+ @retval EFI_SUCCESS The function completed successfully.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+AmlGetEisaIdFromString (
+ IN CONST CHAR8 * EisaIdStr,
+ OUT UINT32 * EisaIdInt
+ )
+{
+ if ((EisaIdStr == NULL) ||
+ (!IsValidPnpId (EisaIdStr)) ||
+ (EisaIdInt == NULL)) {
+ ASSERT (0);
+ return EFI_INVALID_PARAMETER;
+ }
+
+ /* Cf. ACPI 6.4 specification, s19.3.4 "ASL Macros": "Eisaid"
+
+ Converts and compresses the 7-character text argument into its corresponding
+ 4-byte numeric EISA ID encoding (Integer). This can be used when declaring
+ IDs for devices that are EISA IDs.
+
+ The algorithm used to convert the TextID is as shown in the following
+ example:
+ Starting with a seven character input string "PNP0303", we want to create
+ a DWordConst. This string contains a three character manufacturer code
+ "PNP", a three character hex product identifier "030", and a one character
+ revision identifier "3".
+ The compressed manufacturer code is created as follows:
+ 1) Find hex ASCII value for each letter
+ 2) Subtract 40h from each ASCII value
+ 3) Retain 5 least significant bits for each letter and discard remaining
+ 0's:
+
+ Byte 0:
+ Bit 7: reserved (0)
+ Bit 6-2: 1st character of compressed mfg code "P"
+ Bit 1-0: Upper 2 bits of 2nd character of mfg code "N"
+ Byte 1:
+ Bit 7-5: Lower 3 bits of 2nd character of mfg code "N"
+ Bit 4-0: 3rd character of mfg code "P"
+ Byte 2:
+ Bit 7-4: 1st hex digit of product number "0"
+ Bit 3-0: 2nd hex digit of product number "3"
+ Byte 3:
+ Bit 7-4: 3rd hex digit of product number "0"
+ Bit 3-0: 4th hex digit of product number "3"
+ */
+ *EisaIdInt = SwapBytes32 (
+ ((EisaIdStr[0] - 0x40) << 26) |
+ ((EisaIdStr[1] - 0x40) << 21) |
+ ((EisaIdStr[2] - 0x40) << 16) |
+ (HexFromAscii (EisaIdStr[3]) << 12) |
+ (HexFromAscii (EisaIdStr[4]) << 8) |
+ (HexFromAscii (EisaIdStr[5]) << 4) |
+ (HexFromAscii (EisaIdStr[6]))
+ );
+
+ return EFI_SUCCESS;
+}
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