xref: /openbmc/u-boot/doc/README.mpc85xx (revision afa6b551fddc35a83e40c63101947d237bde5183)
1*afa6b551SPrabhakar KushwahaExternal Debug Support
2*afa6b551SPrabhakar Kushwaha----------------------
3*afa6b551SPrabhakar Kushwaha
4*afa6b551SPrabhakar KushwahaFreescale's e500v1 and e500v2 cores (used in mpc85xx chips) have some
5*afa6b551SPrabhakar Kushwaharestrictions on external debugging (JTAG).  In particular, for the debugger to
6*afa6b551SPrabhakar Kushwahabe able to receive control after a single step or breakpoint:
7*afa6b551SPrabhakar Kushwaha	- MSR[DE] must be set
8*afa6b551SPrabhakar Kushwaha	- A valid opcode must be fetchable, through the MMU, from the debug
9*afa6b551SPrabhakar Kushwaha	  exception vector (IVPR + IVOR15).
10*afa6b551SPrabhakar Kushwaha
11*afa6b551SPrabhakar KushwahaTo maximize the time during which this requirement is met, U-Boot sets MSR[DE]
12*afa6b551SPrabhakar Kushwahaimmediately on entry and keeps it set. It also uses a temporary TLB to keep a
13*afa6b551SPrabhakar Kushwahamapping to a valid opcode at the debug exception vector, even if we normally
14*afa6b551SPrabhakar Kushwahadon't support exception vectors being used that early, and that's not the area
15*afa6b551SPrabhakar Kushwahawhere U-Boot currently executes from.
16*afa6b551SPrabhakar Kushwaha
17*afa6b551SPrabhakar KushwahaNote that there may still be some small windows where debugging will not work,
18*afa6b551SPrabhakar Kushwahasuch as in between updating IVPR and IVOR15.
19*afa6b551SPrabhakar Kushwaha
20*afa6b551SPrabhakar KushwahaConfig Switches:
21*afa6b551SPrabhakar Kushwaha----------------
22*afa6b551SPrabhakar Kushwaha
23*afa6b551SPrabhakar KushwahaPlease refer README section "MPC85xx External Debug Support"
24*afa6b551SPrabhakar Kushwaha
25*afa6b551SPrabhakar KushwahaMajor Config Switches during various boot Modes
26*afa6b551SPrabhakar Kushwaha----------------------------------------------
27*afa6b551SPrabhakar Kushwaha
28*afa6b551SPrabhakar KushwahaNOR boot
29*afa6b551SPrabhakar Kushwaha                !defined(CONFIG_SYS_RAMBOOT)
30*afa6b551SPrabhakar KushwahaNOR boot Secure
31*afa6b551SPrabhakar Kushwaha                !defined(CONFIG_SYS_RAMBOOT) && defined(CONFIG_SECURE_BOOT)
32*afa6b551SPrabhakar KushwahaRAMBOOT(SD, SPI & NAND boot)
33*afa6b551SPrabhakar Kushwaha                 defined(CONFIG_SYS_RAMBOOT)
34*afa6b551SPrabhakar KushwahaRAMBOOT Secure (SD, SPI & NAND)
35*afa6b551SPrabhakar Kushwaha                 defined(CONFIG_SYS_RAMBOOT) && defined(CONFIG_SECURE_BOOT)
36*afa6b551SPrabhakar KushwahaNAND SPL BOOT
37*afa6b551SPrabhakar Kushwaha                 defined(CONFIG_SYS_RAMBOOT) && defined(CONFIG_NAND_SPL)
38*afa6b551SPrabhakar Kushwaha
39*afa6b551SPrabhakar Kushwaha
40*afa6b551SPrabhakar KushwahaTLB Entries during u-boot execution
41*afa6b551SPrabhakar Kushwaha-----------------------------------
42*afa6b551SPrabhakar Kushwaha
43*afa6b551SPrabhakar KushwahaNote: Sequence number is in order of execution
44*afa6b551SPrabhakar Kushwaha
45*afa6b551SPrabhakar KushwahaA) defined(CONFIG_SYS_RAMBOOT) i.e. SD, SPI, NAND RAMBOOT & NAND_SPL boot
46*afa6b551SPrabhakar Kushwaha
47*afa6b551SPrabhakar Kushwaha   1) TLB entry to overcome e500 v1/v2 debug restriction
48*afa6b551SPrabhakar Kushwaha       Location   : Label "_start_e500"
49*afa6b551SPrabhakar Kushwaha       TLB Entry  : CONFIG_SYS_PPC_E500_DEBUG_TLB
50*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_MONITOR_BASE --> CONFIG_SYS_MONITOR_BASE
51*afa6b551SPrabhakar Kushwaha       Properties : 256K, AS0, I, IPROT
52*afa6b551SPrabhakar Kushwaha
53*afa6b551SPrabhakar Kushwaha   2) TLB entry for working in AS1
54*afa6b551SPrabhakar Kushwaha       Location   : Label "create_init_ram_area"
55*afa6b551SPrabhakar Kushwaha       TLB Entry  : 15
56*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_MONITOR_BASE --> CONFIG_SYS_MONITOR_BASE
57*afa6b551SPrabhakar Kushwaha       Properties : 1M, AS1, I, G, IPROT
58*afa6b551SPrabhakar Kushwaha
59*afa6b551SPrabhakar Kushwaha   3) TLB entry for the stack during AS1
60*afa6b551SPrabhakar Kushwaha       Location   : Lable "create_init_ram_area"
61*afa6b551SPrabhakar Kushwaha       TLB Entry  : 14
62*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_INIT_RAM_ADDR --> CONFIG_SYS_INIT_RAM_ADDR
63*afa6b551SPrabhakar Kushwaha       Properties : 16K, AS1, IPROT
64*afa6b551SPrabhakar Kushwaha
65*afa6b551SPrabhakar Kushwaha   4) TLB entry for CCSRBAR during AS1 execution
66*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f
67*afa6b551SPrabhakar Kushwaha       TLB Entry  : 13
68*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_CCSRBAR --> CONFIG_SYS_CCSRBAR
69*afa6b551SPrabhakar Kushwaha       Properties : 1M, AS1, I, G
70*afa6b551SPrabhakar Kushwaha
71*afa6b551SPrabhakar Kushwaha   5) Invalidate unproctected TLB Entries
72*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f
73*afa6b551SPrabhakar Kushwaha       Invalidated: 13
74*afa6b551SPrabhakar Kushwaha
75*afa6b551SPrabhakar Kushwaha   6) Create TLB entries as per boards/freescale/<board>/tlb.c
76*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f --> init_tlbs()
77*afa6b551SPrabhakar Kushwaha       Properties : ..., AS0, ...
78*afa6b551SPrabhakar Kushwaha      Please note It can overwrites previous TLB Entries.
79*afa6b551SPrabhakar Kushwaha
80*afa6b551SPrabhakar Kushwaha   7) Disable TLB Entries of AS1
81*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_f --> disable_tlb()
82*afa6b551SPrabhakar Kushwaha       Disable    : 15, 14
83*afa6b551SPrabhakar Kushwaha
84*afa6b551SPrabhakar Kushwaha   8) Update Flash's TLB entry
85*afa6b551SPrabhakar Kushwaha       Location   : Board_init_r
86*afa6b551SPrabhakar Kushwaha       TLB entry  : Search from TLB entries
87*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_FLASH_BASE --> CONFIG_SYS_FLASH_BASE_PHYS
88*afa6b551SPrabhakar Kushwaha       Properties : Board specific size, AS0, I, G, IPROT
89*afa6b551SPrabhakar Kushwaha
90*afa6b551SPrabhakar Kushwaha
91*afa6b551SPrabhakar KushwahaB) !defined(CONFIG_SYS_RAMBOOT) i.e. NOR boot
92*afa6b551SPrabhakar Kushwaha
93*afa6b551SPrabhakar Kushwaha   1) TLB entry to overcome e500 v1/v2 debug restriction
94*afa6b551SPrabhakar Kushwaha       Location   : Label "_start_e500"
95*afa6b551SPrabhakar Kushwaha       TLB Entry  : CONFIG_SYS_PPC_E500_DEBUG_TLB
96*afa6b551SPrabhakar Kushwaha#if defined(CONFIG_SECURE_BOOT)
97*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_MONITOR_BASE --> CONFIG_SYS_PBI_FLASH_WINDOW
98*afa6b551SPrabhakar Kushwaha       Properties : 1M, AS1, I, G, IPROT
99*afa6b551SPrabhakar Kushwaha#else
100*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_MONITOR_BASE & 0xffc00000 --> 0xffc00000
101*afa6b551SPrabhakar Kushwaha       Properties : 4M, AS0, I, G, IPROT
102*afa6b551SPrabhakar Kushwaha#endif
103*afa6b551SPrabhakar Kushwaha
104*afa6b551SPrabhakar Kushwaha   2) TLB entry for working in AS1
105*afa6b551SPrabhakar Kushwaha       Location   : Label "create_init_ram_area"
106*afa6b551SPrabhakar Kushwaha       TLB Entry  : 15
107*afa6b551SPrabhakar Kushwaha#if defined(CONFIG_SECURE_BOOT)
108*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_MONITOR_BASE --> CONFIG_SYS_PBI_FLASH_WINDOW
109*afa6b551SPrabhakar Kushwaha       Properties : 1M, AS1, I, G, IPROT
110*afa6b551SPrabhakar Kushwaha#else
111*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_MONITOR_BASE & 0xffc00000 --> 0xffc00000
112*afa6b551SPrabhakar Kushwaha       Properties : 4M, AS1, I, G, IPROT
113*afa6b551SPrabhakar Kushwaha#endif
114*afa6b551SPrabhakar Kushwaha
115*afa6b551SPrabhakar Kushwaha   3) TLB entry for the stack during AS1
116*afa6b551SPrabhakar Kushwaha       Location   : Lable "create_init_ram_area"
117*afa6b551SPrabhakar Kushwaha       TLB Entry  : 14
118*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_INIT_RAM_ADDR --> CONFIG_SYS_INIT_RAM_ADDR
119*afa6b551SPrabhakar Kushwaha       Properties : 16K, AS1, IPROT
120*afa6b551SPrabhakar Kushwaha
121*afa6b551SPrabhakar Kushwaha   4) TLB entry for CCSRBAR during AS1 execution
122*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f
123*afa6b551SPrabhakar Kushwaha       TLB Entry  : 13
124*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_CCSRBAR --> CONFIG_SYS_CCSRBAR
125*afa6b551SPrabhakar Kushwaha       Properties : 1M, AS1, I, G
126*afa6b551SPrabhakar Kushwaha
127*afa6b551SPrabhakar Kushwaha   5) TLB entry for Errata workaround CONFIG_SYS_FSL_ERRATUM_IFC_A003399
128*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f
129*afa6b551SPrabhakar Kushwaha       TLB Entry  : 9
130*afa6b551SPrabhakar Kushwaha       EPN -->RPN : SRAM_BASE_ADDR --> SRAM_BASE_ADDR
131*afa6b551SPrabhakar Kushwaha       Properties : 1M, AS1, I
132*afa6b551SPrabhakar Kushwaha
133*afa6b551SPrabhakar Kushwaha   6) CONFIG_SYS_FSL_ERRATUM_IFC_A003399 Adjust flash's phys addr
134*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f --> setup_ifc
135*afa6b551SPrabhakar Kushwaha       TLB Entry  : Get Flash TLB
136*afa6b551SPrabhakar Kushwaha       EPN -->RPN : Adjusted flash_phys --> Adjusted flash_phys
137*afa6b551SPrabhakar Kushwaha       Properties : 4M, AS1, I, G, IPROT
138*afa6b551SPrabhakar Kushwaha
139*afa6b551SPrabhakar Kushwaha   7) CONFIG_SYS_FSL_ERRATUM_IFC_A003399: E500 v1,v2 debug restriction
140*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f --> setup_ifc
141*afa6b551SPrabhakar Kushwaha       TLB Entry  : CONFIG_SYS_PPC_E500_DEBUG_TLB
142*afa6b551SPrabhakar Kushwaha       EPN -->RPN : Adjusted flash_phys --> Adjusted flash_phys
143*afa6b551SPrabhakar Kushwaha       Properties : 4M, AS0, I, G, IPROT
144*afa6b551SPrabhakar Kushwaha
145*afa6b551SPrabhakar Kushwaha   8) Invalidate unproctected TLB Entries
146*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f
147*afa6b551SPrabhakar Kushwaha       Invalidated: 13, 9
148*afa6b551SPrabhakar Kushwaha
149*afa6b551SPrabhakar Kushwaha   9) Create TLB entries as per boards/freescale/<board>/tlb.c
150*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_early_f --> init_tlbs()
151*afa6b551SPrabhakar Kushwaha       Properties : ..., AS0, ...
152*afa6b551SPrabhakar Kushwaha      Note: It can overwrites previous TLB Entries
153*afa6b551SPrabhakar Kushwaha
154*afa6b551SPrabhakar Kushwaha   10) Disable TLB Entries of AS1
155*afa6b551SPrabhakar Kushwaha       Location   : cpu_init_f --> disable_tlb()
156*afa6b551SPrabhakar Kushwaha       Disable    : 15, 14
157*afa6b551SPrabhakar Kushwaha
158*afa6b551SPrabhakar Kushwaha   11) Create DDR's TLB entriy
159*afa6b551SPrabhakar Kushwaha       Location   : Board_init_f -> init_func_ram -> initdram
160*afa6b551SPrabhakar Kushwaha       TLB entry  : Search free TLB entry
161*afa6b551SPrabhakar Kushwaha
162*afa6b551SPrabhakar Kushwaha   12) Update Flash's TLB entry
163*afa6b551SPrabhakar Kushwaha       Location   : Board_init_r
164*afa6b551SPrabhakar Kushwaha       TLB entry  : Search from TLB entries
165*afa6b551SPrabhakar Kushwaha       EPN -->RPN : CONFIG_SYS_FLASH_BASE --> CONFIG_SYS_FLASH_BASE_PHYS
166*afa6b551SPrabhakar Kushwaha       Properties : Board specific size, AS0, I, G, IPROT
167