ARM: 8618/1: decompressor: reset ttbcr fields to use TTBR0 on ARMv7

If the bootloader uses the long descriptor format and jumps to kernel decompressor code, TTBCR may not be in a right state. Before enabling the MMU, it is required to clear the TTBCR.PD0 field to use TTBR0 for translation table walks. The commit dbece45894d3a ("ARM: 7501/1: decompressor: reset ttbcr for VMSA ARMv7 cores") does the reset of TTBCR.N, but doesn't consider all the bits for the size of TTBCR.N. Clear TTBCR.PD0 field and reset all the three bits of TTBCR.N to indicate the use of TTBR0 and the correct base address width.

Srinivas Ramana committed 10 years ago

Commit 117e5e91 parent d2482201 file · +1 −1Browse files

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arch/arm/boot/compressed/head.S+1−1

@@ -779,7 +779,7 @@ __armv7_mmu_cache_on: · 778 unmodified lines
779	779	orrne r0, r0, #1 @ MMU enabled
780	780	movne r1, #0xfffffffd @ domain 0 = client
781	781	bic r6, r6, #1 << 31 @ 32-bit translation system
782		− bic r6, r6, #3 << 0 @ use only ttbr0
	782	+ bic r6, r6, #(7 << 0) \| (1 << 4) @ use only ttbr0
783	783	mcrne p15, 0, r3, c2, c0, 0 @ load page table pointer
784	784	mcrne p15, 0, r1, c3, c0, 0 @ load domain access control
785	785	mcrne p15, 0, r6, c2, c0, 2 @ load ttb control