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author | Giorgio Dal Molin <giorgio.nicole@arcor.de> | 2020-04-07 17:31:11 +0200 |
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committer | Sascha Hauer <s.hauer@pengutronix.de> | 2020-04-14 12:03:24 +0200 |
commit | b1d30239ccde137bcd998437ef96d4af3a696415 (patch) | |
tree | 62fd0b0f35916e8f8724634b458ebc2075e86922 /arch/arm/cpu/mmu.h | |
parent | 41594beb02d714e2641c70d36a442b1c1e1964e3 (diff) | |
download | barebox-b1d30239ccde137bcd998437ef96d4af3a696415.tar.gz barebox-b1d30239ccde137bcd998437ef96d4af3a696415.tar.xz |
ARM: i.MX: fixed enabling the MMU after switching in non secure mode.
The Domain Access Control Register (DACR) in CP15 is banked between
secure and non secure mode: there a copy of the reg. in secure mode and a
second copy in non secure mode.
As barebox boots on the imx7 SOC it runs in secure mode and initializes
the secure-mode copy of DACR (with 0x00000001).
After switching to non secure mode, for example with the command 'smc -n'
or while booting a kernel image with global.bootm.secure_state=nonsecure,
the active value of DACR is the copy in non-secure mode and that copy
was still uninitialized and in an UNKNOWN state.
This caused the cpu to hang as soon as the MMU was enabled in non-secure
mode.
We fix this by reading the DACR value in secure mode just before switching
to non secure and then initializing it again with the same value.
Signed-off-by: Giorgio Dal Molin <giorgio.nicole@arcor.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Diffstat (limited to 'arch/arm/cpu/mmu.h')
-rw-r--r-- | arch/arm/cpu/mmu.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/arm/cpu/mmu.h b/arch/arm/cpu/mmu.h index 6e7a4c0350..c85e0ea050 100644 --- a/arch/arm/cpu/mmu.h +++ b/arch/arm/cpu/mmu.h @@ -39,6 +39,15 @@ static inline void set_ttbr(void *ttb) #define DOMAIN_CLIENT 1 #define DOMAIN_MANAGER 3 +static inline unsigned long get_domain(void) +{ + unsigned long dacr; + + asm volatile ("mrc p15, 0, %0, c3, c0, 0" : "=r"(dacr)); + + return dacr; +} + static inline void set_domain(unsigned val) { /* Set the Domain Access Control Register */ |