Changes between Initial Version and Version 1 of kernel_init

Timestamp:

Nov 1, 2014, 5:24:48 PM (10 years ago)

Author:

alain

Comment:

--

kernel_init

@@ +1 @@
+= GIET_VM / Kernel Initialisation =
+
+
+The [source:soft/giet_vm/giet_kernel/kernel_init.c kernel_init()] function completes the system initialisation, that has been done by the boot-loader running on processor[0,0,0]. This kernel_init() function is executed sequencially by all processors. 
+
+It makes the following assuptions, regarding the work done by the boot-loader:
+
+ * The page tables associated to the various vspaces have been build in physical memory.
+ * All schedulers (including all task contexts) have been initialised.
+ * For each task, the page table virtual address is stored in the CTX_PTAB slot.
+ * For each task, the page table physical address is stored in the CTX_PTPR slots.
+ * The CP0_SCHED register of each processor contains a pointer on its private scheduler (virtual address).
+ * The CP2_PTPR register contains a pointer on the page table of vspace[0] (physical address>>13). 
+ * For all processors, the MMU is activated (CP2_MODE contains 0xF).
+
+Each processor performs the following actions:
+ 1. contribute to _schedulers_paddr[] array initialisation.
+ 2. contribute to _ptabs_paddr[] and _ptabs_vaddr arrays initialisation. 
+ 3. completes task context initialisation for each allocated task.
+ 4. compute and set the XCU mask for its private XCU channel.
+ 5. initialise its private TICK timer (if tasks > 0)
+ 6. initialise the "idle" task context in its private scheduler
+ 7. initialise SP, SR, PTPR, EPC registers and jump to user code with an eret. 
+
+This kernel_init code must be loaded in .kinit section, in order to control the seg_kinit_base value that is used by the boot code to jump into kernel code.
+
+