User manual

Table Of Contents
Zynq-7000 AP SoC Technical Reference Manual www.xilinx.com 202
UG585 (v1.11) September 27, 2016
Chapter 6: Boot and Configuration
Post BootROM Security
If secure mode is enabled, the AES unit is accessible post BootROM. In non-secure mode, the AES
unit is not accessible.
The BootROM locks several bits in the DevC module prior to exiting to ensure security. The bits the
BootROM locks are listed in Table 6-21; where
1 = locked. The Lock bits are used to disable writes to
bits in the devcfg.CTRL register. Once a lock bit is set, it cannot be cleared except by a POR reset. The
BootROM will lock some of these bits before turning PS control over to the FSPL/User code.
Post BootROM Debug
In the event of a failure while booting non-secure the BootROM enables JTAG access so that the
REBOOT_STATUS and other registers can be read using the DAP controller. A debugging tool like
XMD has full access to the processor when JTAG is enabled and includes the DAP controller in the
chain.
X-Ref Target - Figure 6-11
Figure 6-11: System Memory Map During BootROM Execution
Table 6-21: devcfg.LOCK Register
Bit Position Bit Name
BootROM Secure
Boot Lock Status
BootROM
Non-Secure Boot
Lock Status
31:5 Reserved ~~
4 AES_FUSE_LOCK 10
3 AES_EN_LOCK 0 1
2SEU_LOCK 00
1 SEC_LOCK 10
0DBG_LOCK 00
'XULQJ
%RRW520/RDGLQJ)6%/
8*BFBB
2&05$0
(PSW\
''5
3HULSKHUDOV
(PSW\
2&05$0
0%
*%
0B$;,B*3
0B$;,B*3
*%
*%
*%
.%
$W+DQGRIIIURP
%RRW520([HFXWLRQWR)6%/8VHU&RGH
.%%RRW5203URJUDP0HPRU\
2&0520
.%
.%)6%/&RGHEXIIHU
2&00HPRU\
(PSW\
''5
3HULSKHUDOV
(PSW\
2&00HPRU\
0%
*%
0B$;,B*3
0B$;,B*3
*%
*%
*%
.%
(PSW\
.%
.%)6%/&RGH
3DUDPHWHUV9DULDEOHV
DQG%RRW520+HDGHU
.%%RRW520&RGH
.%)6%/3URJUDP0HPRU\