The device attached to the device SATA for boot operation must meet the following requirements:
- It must be compliant with the Serial ATA Standard specification, rev. 2.6.
- It must support READ SECTOR(s) ATA command (code 0x20) as defined in the ATA / ATAPI - 7 specification.
- It must be connected directly to the device SATA IOs – sata_tx / sata_ty, sata_rx / sata_ry (no port multiplier connected).
- It must have been already powered by the companion chip or external supply before start of the boot procedure.
- It must be taken in consideration for the device that maximum power on ready time allowed by ROM Code is 900ms. First COMRESET procedure targeting the attached device is triggered 300ms after device SATA subsystem initialization by ROM Code.
Figure 33-30 highlights the booting of the platform from the SSD device.
The device booting from an attached SATA mass storage memory device is performed in the following steps:
- At reset or power on, the device ROM code boots and checks for the SSD / HDD to be ready.
- The SSD / HDD transfers the boot-loader to the internal RAM of device.
- The OS in the SSD or HDD is downloaded into DDR memory and the platform is ready.