Optionally Perform A Serial Boot - STMicroelectronics SPC572L series Reference Manual

RM0400
operations in BAF. No parameters are passed to this function and no return value is
expected.
Warning:
BAF executes the callback function as the DCF records are parsed. Therefore, several
callback functions maybe executed by writing several DCF records that write to the callback
DCF clients. The callback functions are executed in the same order as the DCF records.
52.2.4.6 SER_BOOT_CBACK – BAF serial boot DCF client
BAF parses the DCF records. If BAF finds a record with CS14 set and address field as
0211h while parsing, BAF programs this serial boot DCF client. This DCF client is written
with a 32 bit start address of function which is invoked by BAF. The BAF code checks the
start address is within UTEST or within the BAF flash memory block, and then passes
program flow to this address. If the address is found to be outside the UTEST and BAF flash
memory block, no function call is executed. The DCF client execution is aborted and BAF
moves on to the next DCF record. The function that is called is expected to comply with
power.org EABI and to terminate in orderly manner. An incorrectly written function causes
unpredictable operations in BAF. No parameters are passed to this function.
Warning:
The serial boot callback function returns a char value. The returned value informs BAF if
serial boot or normal internal flash boot should be executed (see
regarding return value).
Return values
02h–FFh
52.2.5

Optionally perform a serial boot

If no boot header is found in one of the locations mentioned above or customer selects
serial boot using serial boot DCF client, then BAF determines the lifecycle status of the
device. If the Life Cycle is in CUST_DELIV (Customer Delivery), it attempts a serial boot.
Otherwise, the boot has failed and the BAF issues a destructive reset.
Excessively long callback functions could cause the
watchdog timer to time-out and cause a reset.
No parameters are passed to the function invoked by the
BAF. Excessively long callback functions could cause the
watchdog timer to time-out and cause a reset.
Table 879. Serial boot callback function return value definition
Boot from internal flash using standard search for boot record (see 'Serial
00h
boot header and boot options' in configuration section).
Serial boot using both M_CAN and LINFlexD (in UART mode) (see 'Serial
01h
boot header and boot options' in configuration section).
Reserved
DocID027809 Rev 4
Boot Assist Flash (BAF)
Table 879
Description
for details
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