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Diffstat (limited to 'Documentation/xtensa/mmu.txt')
| -rw-r--r-- | Documentation/xtensa/mmu.txt | 46 |
1 files changed, 0 insertions, 46 deletions
diff --git a/Documentation/xtensa/mmu.txt b/Documentation/xtensa/mmu.txt deleted file mode 100644 index 2b1af7606d57..000000000000 --- a/Documentation/xtensa/mmu.txt +++ /dev/null @@ -1,46 +0,0 @@ -MMUv3 initialization sequence. - -The code in the initialize_mmu macro sets up MMUv3 memory mapping -identically to MMUv2 fixed memory mapping. Depending on -CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX symbol this code is -located in one of the following address ranges: - - 0xF0000000..0xFFFFFFFF (will keep same address in MMU v2 layout; - typically ROM) - 0x00000000..0x07FFFFFF (system RAM; this code is actually linked - at 0xD0000000..0xD7FFFFFF [cached] - or 0xD8000000..0xDFFFFFFF [uncached]; - in any case, initially runs elsewhere - than linked, so have to be careful) - -The code has the following assumptions: - This code fragment is run only on an MMU v3. - TLBs are in their reset state. - ITLBCFG and DTLBCFG are zero (reset state). - RASID is 0x04030201 (reset state). - PS.RING is zero (reset state). - LITBASE is zero (reset state, PC-relative literals); required to be PIC. - -TLB setup proceeds along the following steps. - - Legend: - VA = virtual address (two upper nibbles of it); - PA = physical address (two upper nibbles of it); - pc = physical range that contains this code; - -After step 2, we jump to virtual address in 0x40000000..0x5fffffff -that corresponds to next instruction to execute in this code. -After step 4, we jump to intended (linked) address of this code. - - Step 0 Step1 Step 2 Step3 Step 4 Step5 - ============ ===== ============ ===== ============ ===== - VA PA PA VA PA PA VA PA PA - ------ -- -- ------ -- -- ------ -- -- - E0..FF -> E0 -> E0 E0..FF -> E0 F0..FF -> F0 -> F0 - C0..DF -> C0 -> C0 C0..DF -> C0 E0..EF -> F0 -> F0 - A0..BF -> A0 -> A0 A0..BF -> A0 D8..DF -> 00 -> 00 - 80..9F -> 80 -> 80 80..9F -> 80 D0..D7 -> 00 -> 00 - 60..7F -> 60 -> 60 60..7F -> 60 - 40..5F -> 40 40..5F -> pc -> pc 40..5F -> pc - 20..3F -> 20 -> 20 20..3F -> 20 - 00..1F -> 00 -> 00 00..1F -> 00 |