Apple Platform Feature Information (Type 133)

Source: the AppleSmBios.h header of OpenCore, Include/Apple/IndustryStandard.

Tells the features of the platform, which macOS reads. Older Macs carry no such structure.

Table 1. Apple Platform Feature Information structure
Offset	Version	Name	Length	Value	Description
`0x00`	2.0+	Type	`BYTE`	`133`	Apple Platform Feature Information indicator
`0x01`	2.0+	Length	`BYTE`	Varies	Length of the structure
`0x02`	2.0+	Handle	`WORD`	Varies
`0x04`	2.0+	Platform Feature	`QWORD`	Bit field	Features of the platform, see Platform Features

1. Apple Platform Feature Information — Platform Features

Table 2. Apple Platform Feature Information: Platform Features
Bit	Meaning
1	System memory is soldered, and cannot be replaced
2	Headless GPU, of no display connectors, is present
3	Supports host power management
4	Supports the chime at boot

The other bits are of no known meaning.