3,260
edits
Changes
Created page with "{{InfoBoxTop}} {{AppliesToAxelLite}} {{InfoBoxBottom}} == System boot == The boot process begins at Power On Reset (POR) where the hardware reset logic forces the ARM core t..."
{{InfoBoxTop}}
{{AppliesToAxelLite}}
{{InfoBoxBottom}}
== System boot ==
The boot process begins at Power On Reset (POR) where the hardware reset logic forces the ARM core to begin execution starting from the on-chip boot ROM. The boot ROM:
* determines whether the boot is secure or non-secure
* performs some initialization of the system and clean-ups
* reads the mode pins to determine the primary boot device
* once it is satisfied, it executes the boot code
== Boot options ==
Two options are available related to system boot. They are identified by the Boot field of the ordering code as follows:
* 0: SPI NOR / SD option (SOM code: DXLxxxx0xxR)
* 1: NAND / SD option (SOM code: DXLxxxx1xxR)
For both options the selection of primary boot device is determined by the BOOT_MODE_SEL signal as described in the following sections. BOOT_MODE_SEL is latched when processor reset is released.
In any case, boot process is managed by on-chip boot ROM code that is described in detail in processor's Reference Manual.
=== SPI NOR / SD option ===
Selection of primary boot device is determined by the BOOT_MODE_SEL signal as follows:
* BOOT_MODE_SEL = 0
** primary boot device is SD1 (see section TBD for more details)
** in case no valid image is found in SD card, boot ROM shall enable USB serial download mode automatically
* BOOT_MODE_SEL = 1 or floating
** primary boot device is SPI NOR flash connected to eCSPI1 (see section TBD for more details)
** in case no valid image is found in NOR flash, boot ROM shall enable USB serial download mode automatically
=== NAND / SD option ===
Selection of primary boot device is determined by the BOOT_MODE_SEL signal as follows:
* BOOT_MODE_SEL = 0
** primary boot device is SD1 (see section TBD for more details)
** in case no valid image is found in SD card, boot ROM shall enable USB serial download mode automatically
* BOOT_MODE_SEL = 1 or floating
** primary boot device is NAND flash (see section TBD for more details)
** in case no valid image is found in NAND flash, boot ROM shall enable USB serial download mode automatically
{{AppliesToAxelLite}}
{{InfoBoxBottom}}
== System boot ==
The boot process begins at Power On Reset (POR) where the hardware reset logic forces the ARM core to begin execution starting from the on-chip boot ROM. The boot ROM:
* determines whether the boot is secure or non-secure
* performs some initialization of the system and clean-ups
* reads the mode pins to determine the primary boot device
* once it is satisfied, it executes the boot code
== Boot options ==
Two options are available related to system boot. They are identified by the Boot field of the ordering code as follows:
* 0: SPI NOR / SD option (SOM code: DXLxxxx0xxR)
* 1: NAND / SD option (SOM code: DXLxxxx1xxR)
For both options the selection of primary boot device is determined by the BOOT_MODE_SEL signal as described in the following sections. BOOT_MODE_SEL is latched when processor reset is released.
In any case, boot process is managed by on-chip boot ROM code that is described in detail in processor's Reference Manual.
=== SPI NOR / SD option ===
Selection of primary boot device is determined by the BOOT_MODE_SEL signal as follows:
* BOOT_MODE_SEL = 0
** primary boot device is SD1 (see section TBD for more details)
** in case no valid image is found in SD card, boot ROM shall enable USB serial download mode automatically
* BOOT_MODE_SEL = 1 or floating
** primary boot device is SPI NOR flash connected to eCSPI1 (see section TBD for more details)
** in case no valid image is found in NOR flash, boot ROM shall enable USB serial download mode automatically
=== NAND / SD option ===
Selection of primary boot device is determined by the BOOT_MODE_SEL signal as follows:
* BOOT_MODE_SEL = 0
** primary boot device is SD1 (see section TBD for more details)
** in case no valid image is found in SD card, boot ROM shall enable USB serial download mode automatically
* BOOT_MODE_SEL = 1 or floating
** primary boot device is NAND flash (see section TBD for more details)
** in case no valid image is found in NAND flash, boot ROM shall enable USB serial download mode automatically
