SPRABA5D January 2014 – January 2019 AM1802 , AM1802 , AM1806 , AM1806 , AM1808 , AM1808 , AM1810 , AM1810
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Using the AM18xx Bootloader
- Trademarks
- 1 Introduction
- 2 Boot Modes
- 3 Non-AIS Boot Modes
- 4
Application Image Script (AIS) Boot
- 4.1 Section Load Command (0x58535901)
- 4.2 Section Fill Command (0x5853590A)
- 4.3 Enable CRC Command (0x58535903)
- 4.4 Disable CRC Command (0x58535904)
- 4.5 Validate CRC Command (0x58535902)
- 4.6 Jump & Close Command (0x58535906)
- 4.7 Jump Command (0x58535905)
- 4.8 Sequential Read Enable Command (0x58535963)
- 4.9 Function Execute Command (0x5853590D)
- 4.10 Boot Table Command (0x58535907)
- 5
AISgen: Tool to Generate Boot Script (AIS Image)
- 5.1 Installation
- 5.2 Getting Started
- 5.3
Generating AIS
- 5.3.1 Boot Mode and Boot Peripheral Setup
- 5.3.2 Phase-Locked Loop (PLL) Setup
- 5.3.3 Synchronous Dynamic Random Access Memory (SDRAM) Setup
- 5.3.4 DDR Setup
- 5.3.5 PSC Setup
- 5.3.6 Pin Multiplexing Setup
- 5.3.7 Application File Selection
- 5.3.8 AIS File Selection
- 5.3.9 Status and Messages
- 5.3.10 Additional AIS Options
- 5.3.11 Command Line Usage
- 6 Master Boot – Booting From a Slave Memory Device
- 7 Slave Boot – Booting From an External Master Host
- 8 UART Boot Host - Using Your PC as a UART Boot Master
- 9 Boot Requirements, Constraints and Default Settings
- 10 References
- A Boot Mode Selection Table
- B Details of Supported NAND Devices
- C CRC Computation Algorithm
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D Details of Pre-Defined ROM Functions
- D.1 PLL0 Configuration (Index = 0, Argument Count = 2)
- D.2 PLL1 Configuration (Index = 1, Argument Count = 2)
- D.3 Clock Configuration (Index = 2, Argument Count = 1)
- D.4 mDDR/DDR2 Controller Configuration (Index = 3, Argument Count = 8)
- D.5 EMIFA SDRAM Configuration (Index = 4, Argument Count = 5)
- D.6 EMIFA Async Configuration (Index = 5, Argument Count = 5)
- D.7 PLL and Clock Configuration (Index = 6, Argument Count = 3)
- D.8 Power and Sleep Configuration (PSC) (Index = 7, Argument Count = 1)
- D.9 Pinmux Configuration (Index = 8, Argument Count = 3)
- E ROM Revision History
- Revision History
4.5 Validate CRC Command (0x58535902)
This command is used to validate the CRC calculated by the bootloader.
Figure 10. Validate CRC Command This command takes two arguments: the CRC and the seek value. The CRC is the expected value of the CRC with which the calculated CRC should be compared. In the case of a CRC match, the seek value is ignored and the next command is executed. However, in the case of a CRC mismatch, the seek value can be added to the current position in AIS to locate the last Section Load/Section Fill command so that the command can be executed again.
Figure 11. Handling CRC Error This command behaves differently for master- and slave-boot modes. In master-boot mode, the bootloader reads the expected CRC from the boot device and compares it with the calculated CRC. In case of an error, the bootloader adds the seek value to the current read position in AIS and starts executing commands from that position in AIS.
Figure 12. Validate CRC Flow for Slave Mode In slave-boot mode, on receiving the Validate CRC command, the bootloader provides the calculated CRC to the host. The host then compares this value with the one from AIS and updates its AIS read position, depending on the result of the CRC comparison. In the case of an error, the host sends the Start-Over command to the device so that the bootloader can re-initialize the calculated CRC and be ready to receive the next command.
Figure 13. Start-Over Command The Start-Over command (0x58535908) takes no arguments or data. This command does not appear in AIS and is only used in slave-boot mode by the host to recover from a CRC error.