To support loading a 32-bit OS, the execution state will change from
AArch64 to AArch32 when jumping to kernel.
The architecture information will be got through checking FIT
image, then U-Boot will load 32-bit OS or 64-bit OS automatically.
Signed-off-by: Ebony Zhu <ebony....@nxp.com>
Signed-off-by: Alison Wang <alison.w...@nxp.com>
Signed-off-by: Chenhui Zhao <chenhui.z...@nxp.com>
---
Changes in v4:
- Correct config ARM64_SUPPORT_AARCH32.
- Omit arch and ftaddr arguments.
- Rename "xreg5" to "tmp".
- Use xxx_RES1 to combine all RES1 fields in xxx register.
- Use an immediate cmp directly.
- Use #ifdef for CONFIG_ARM64_SUPPORT_AARCH32.
Changes in v3:
- Comments the functions and the arguments.
- Rename the real parameters.
- Use the macros instead of the magic values.
- Remove the redundant codes.
- Clean up all of the mess in boot_jump_linux().
- Add CONFIG_ARM64_SUPPORT_AARCH32 to detect for some ARM64 system doesn't
support AArch32 state.
Changes in v2:
- armv8_switch_to_el2_aarch32() is removed. armv8_switch_to_el2_m is used
to switch to AArch64 EL2 or AArch32 Hyp.
- armv8_switch_to_el1_aarch32() is removed. armv8_switch_to_el1_m is used
to switch to AArch64 EL1 or AArch32 SVC.
arch/arm/Kconfig | 6 ++
arch/arm/cpu/armv8/start.S | 1 +
arch/arm/cpu/armv8/transition.S | 8 +-
arch/arm/include/asm/macro.h | 172 ++++++++++++++++++++++++++++++----------
arch/arm/include/asm/system.h | 111 +++++++++++++++++++++++++-
arch/arm/lib/bootm.c | 19 ++++-
common/image-fit.c | 19 ++++-
7 files changed, 284 insertions(+), 52 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 77eab66..9cf4acd 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -91,6 +91,12 @@ config SYS_L2CACHE_OFF
If SoC does not support L2CACHE or one do not want to enable
L2CACHE, choose this option.
+config ARM64_SUPPORT_AARCH32
+ bool "ARM64 system support AArch32 execution state"
+ default y if ARM64 && !TARGET_THUNDERX_88XX
+ help
+ This ARM64 system supports AArch32 execution state.
+
choice
prompt "Target select"
default TARGET_HIKEY
diff --git a/arch/arm/cpu/armv8/start.S b/arch/arm/cpu/armv8/start.S
index e933021..dd69501 100644
--- a/arch/arm/cpu/armv8/start.S
+++ b/arch/arm/cpu/armv8/start.S
@@ -234,6 +234,7 @@ WEAK(lowlevel_init)
/*
* All slaves will enter EL2 and optionally EL1.
*/
+ ldr x3, =ES_TO_AARCH64
bl armv8_switch_to_el2
#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
bl armv8_switch_to_el1
diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S
index 253a39b..e61b6ae 100644
--- a/arch/arm/cpu/armv8/transition.S
+++ b/arch/arm/cpu/armv8/transition.S
@@ -11,13 +11,13 @@
#include <asm/macro.h>
ENTRY(armv8_switch_to_el2)
- switch_el x0, 1f, 0f, 0f
+ switch_el x4, 1f, 0f, 0f
0: ret
-1: armv8_switch_to_el2_m x0
+1: armv8_switch_to_el2_m x0, x3, x4
ENDPROC(armv8_switch_to_el2)
ENTRY(armv8_switch_to_el1)
- switch_el x0, 0f, 1f, 0f
+ switch_el x4, 0f, 1f, 0f
0: ret
-1: armv8_switch_to_el1_m x0, x1
+1: armv8_switch_to_el1_m x0, x3, x4
ENDPROC(armv8_switch_to_el1)
diff --git a/arch/arm/include/asm/macro.h b/arch/arm/include/asm/macro.h
index 9bb0efa..109724f 100644
--- a/arch/arm/include/asm/macro.h
+++ b/arch/arm/include/asm/macro.h
@@ -8,6 +8,9 @@
#ifndef __ASM_ARM_MACRO_H__
#define __ASM_ARM_MACRO_H__
+
+#include <asm/system.h>
+
#ifdef __ASSEMBLY__
/*
@@ -135,13 +138,20 @@ lr .req x30
#endif
.endm
-.macro armv8_switch_to_el2_m, xreg1
- /* 64bit EL2 | HCE | SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1 */
- mov \xreg1, #0x5b1
- msr scr_el3, \xreg1
+/*
+ * Switch from EL3 to EL2 for ARMv8
+ * @ep: kernel entry point
+ * @flag: The execution state flag for lower exception
+ * level, ES_TO_AARCH64 or ES_TO_AARCH32
+ * @tmp: temporary register
+ *
+ * x1 is machine nr and x2 is ftaddr, they will be passed
+ * to the guest.
+ */
+.macro armv8_switch_to_el2_m, ep, flag, tmp
msr cptr_el3, xzr /* Disable coprocessor traps to EL3 */
- mov \xreg1, #0x33ff
- msr cptr_el2, \xreg1 /* Disable coprocessor traps to EL2 */
+ mov \tmp, #CPTR_EL2_RES1
+ msr cptr_el2, \tmp /* Disable coprocessor traps to EL2 */
/* Initialize Generic Timers */
msr cntvoff_el2, xzr
@@ -152,45 +162,91 @@ lr .req x30
* and RES0 bits (31,30,27,26,24,21,20,17,15-13,10-6) +
* EE,WXN,I,SA,C,A,M to 0
*/
- mov \xreg1, #0x0830
- movk \xreg1, #0x30C5, lsl #16
- msr sctlr_el2, \xreg1
+ ldr \tmp, =(SCTLR_EL2_RES1 | SCTLR_EL2_EE_LE |\
+ SCTLR_EL2_WXN_DIS | SCTLR_EL2_ICACHE_DIS |\
+ SCTLR_EL2_SA_DIS | SCTLR_EL2_DCACHE_DIS |\
+ SCTLR_EL2_ALIGN_DIS | SCTLR_EL2_MMU_DIS)
+ msr sctlr_el2, \tmp
+
+ mov \tmp, sp
+ msr sp_el2, \tmp /* Migrate SP */
+ mrs \tmp, vbar_el3
+ msr vbar_el2, \tmp /* Migrate VBAR */
+
+ /* Check switch to AArch64 EL2 or AArch32 Hypervisor mode */
+ cmp \flag, #ES_TO_AARCH32
+ b.eq 1f
+
+ /*
+ * The next lower exception level is AArch64, 64bit EL2 | HCE |
+ * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
+ */
+ ldr \tmp, =(SCR_EL3_RW_AARCH64 | SCR_EL3_HCE_EN |\
+ SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
+ SCR_EL3_NS_EN)
+ msr scr_el3, \tmp
/* Return to the EL2_SP2 mode from EL3 */
- mov \xreg1, sp
- msr sp_el2, \xreg1 /* Migrate SP */
- mrs \xreg1, vbar_el3
- msr vbar_el2, \xreg1 /* Migrate VBAR */
- mov \xreg1, #0x3c9
- msr spsr_el3, \xreg1 /* EL2_SP2 | D | A | I | F */
+ ldr \tmp, =(SPSR_EL_DEBUG_MASK | SPSR_EL_SERR_MASK |\
+ SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
+ SPSR_EL_M_AARCH64 | SPSR_EL_M_EL2H)
+ msr spsr_el3, \tmp
msr elr_el3, lr
