| Message ID | 1332304952-10765-1-git-send-email-prabhakar@freescale.com |
|---|---|
| State | Superseded |
| Delegated to: | Andy Fleming |
| Headers | show |
On 03/20/2012 11:42 PM, Prabhakar Kushwaha wrote: > diff --git a/README b/README > index 8964672..48e50ed 100644 > --- a/README > +++ b/README > @@ -3347,6 +3347,20 @@ Low Level (hardware related) configuration options: > be used if available. These functions may be faster under some > conditions but may increase the binary size. > > +E500 (MPC85xx) External Debug Support > +------------------------------------- > +-CONFIG_E500 > + Enables BOOKE e500 family.It includes e500, e500v2 e500mc, > + e5500 processor etc. This is not a debug-specific option. What's wrong with putting both of these options under the existing "85xx CPU Options" section? -Scott
Hi Scott, Thanks for reviewing it. Please find my reply in-lined. On Wednesday 21 March 2012 10:01 PM, Scott Wood wrote: > On 03/20/2012 11:42 PM, Prabhakar Kushwaha wrote: >> diff --git a/README b/README >> index 8964672..48e50ed 100644 >> --- a/README >> +++ b/README >> @@ -3347,6 +3347,20 @@ Low Level (hardware related) configuration options: >> be used if available. These functions may be faster under some >> conditions but may increase the binary size. >> >> +E500 (MPC85xx) External Debug Support >> +------------------------------------- >> +-CONFIG_E500 >> + Enables BOOKE e500 family.It includes e500, e500v2 e500mc, >> + e5500 processor etc. > This is not a debug-specific option. What's wrong with putting both of > these options under the existing "85xx CPU Options" section? Yes. Both CONFIG_E500 and CONFIG_SYS_PPC_E500_DEBUG_TLB can be put under "85xx CPU Options". I made separate section thinking of CONFIG_SYS_PPC_E500_DEBUG_TLB as it required for overcoming e500 v1/v2 debugging restriction. i will send the updated patch. --Prabhakar
diff --git a/README b/README index 8964672..48e50ed 100644 --- a/README +++ b/README @@ -3347,6 +3347,20 @@ Low Level (hardware related) configuration options: be used if available. These functions may be faster under some conditions but may increase the binary size. +E500 (MPC85xx) External Debug Support +------------------------------------- +-CONFIG_E500 + Enables BOOKE e500 family.It includes e500, e500v2 e500mc, + e5500 processor etc. + +- CONFIG_SYS_PPC_E500_DEBUG_TLB + Enables a temporary TLB entry to be used during boot to work + around limitations in e500v1 and e500v2 external debugger + support. This reduces the portions of the boot code where + breakpoints and single stepping do not work. The value of this + symbol should be set to the TLB1 entry to be used for this + purpose. + Freescale QE/FMAN Firmware Support: ----------------------------------- diff --git a/doc/README.mpc85xx b/doc/README.mpc85xx new file mode 100644 index 0000000..dbd74be --- /dev/null +++ b/doc/README.mpc85xx @@ -0,0 +1,23 @@ +External Debug Support +---------------------- + +Freescale's e500v1 and e500v2 cores (used in mpc85xx chips) have some +restrictions on external debugging (JTAG). In particular, for the debugger to +be able to receive control after a single step or breakpoint: + - MSR[DE] must be set + - A valid opcode must be fetchable, through the MMU, from the debug + exception vector (IVPR + IVOR15). + +To maximize the time during which this requirement is met, U-Boot sets MSR[DE] +immediately on entry and keeps it set. It also uses a temporary TLB to keep a +mapping to a valid opcode at the debug exception vector, even if we normally +don't support exception vectors being used that early, and that's not the area +where U-Boot currently executes from. + +Note that there may still be some small windows where debugging will not work, +such as in between updating IVPR and IVOR15. + +Config Switches: +---------------- + +Please refer README section "MPC85xx External Debug Support"