Boot Sequence

When the SoC loads and runs your software application, there are several boot sequence scenarios, depending on where the application is stored. With a bootloader, the embedded program loads the user binary from secondary memory to primary memory during boot up. If your software application is small enough (less than 4 KB), you can embed it in the on-chip RAM. It is recommended to follow the procedure in Modify the Bootloader for building an embedded user application.

Figure 1. Boot Sequence Flow Chart
Table 1. User Application
Item Case A Case B Case C
Bootloader needed? Yes Yes No
Application storage SPI flash SPI flash On-chip RAM
Execute location External memory On-chip RAM On-chip RAM

The following sections describe these cases in more detail.

The Sapphire SoC supports multiple cores; Booting Multiple Cores describes the programming sequence.