[U-Boot] [PATCH v5 1/2] armv8: Support loading 32-bit OS in AArch32 execution state
Alison Wang
b18965 at freescale.com
Thu Jul 7 08:30:47 CEST 2016
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.zhu at nxp.com>
Signed-off-by: Alison Wang <alison.wang at nxp.com>
Signed-off-by: Chenhui Zhao <chenhui.zhao at nxp.com>
---
Changes in v5:
- Modified armv8_switch_to_el2(). It will always jump to ep when switching to AArch64 or AArch32 modes.
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 | 2 +
arch/arm/cpu/armv8/transition.S | 4 +-
arch/arm/include/asm/macro.h | 80 ++++++++++++++++++++++++-------
arch/arm/include/asm/system.h | 104 +++++++++++++++++++++++++++++++++++++++-
arch/arm/lib/bootm.c | 13 ++++-
common/image-fit.c | 19 +++++++-
7 files changed, 206 insertions(+), 22 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 3237a74..1b30447 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -99,6 +99,12 @@ config ENABLE_ARM_SOC_BOOT0_HOOK
ARM_SOC_BOOT0_HOOK which contains the required assembler
preprocessor code.
+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 ab434a6..a0c55d7 100644
--- a/arch/arm/cpu/armv8/start.S
+++ b/arch/arm/cpu/armv8/start.S
@@ -244,6 +244,8 @@ WEAK(lowlevel_init)
/*
* All slaves will enter EL2.
*/
+ mov x3, lr
+ ldr x4, =ES_TO_AARCH64
bl armv8_switch_to_el2
#endif /* CONFIG_ARMV8_MULTIENTRY */
diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S
index 209d5c8..62d54b3 100644
--- a/arch/arm/cpu/armv8/transition.S
+++ b/arch/arm/cpu/armv8/transition.S
@@ -11,7 +11,7 @@
#include <asm/macro.h>
ENTRY(armv8_switch_to_el2)
- switch_el x0, 1f, 0f, 0f
+ switch_el x5, 1f, 0f, 0f
0: ret
-1: armv8_switch_to_el2_m x0
+1: armv8_switch_to_el2_m x3, x4, x5
ENDPROC(armv8_switch_to_el2)
diff --git a/arch/arm/include/asm/macro.h b/arch/arm/include/asm/macro.h
index c1b3452..5108900 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 +138,21 @@ 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
+ *
+ * For loading 32-bit OS, x1 is machine nr and x2 is ftaddr.
+ * For loading 64-bit OS, x0 is physical address to the FDT blob.
+ * 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
@@ -152,18 +163,55 @@ 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 */
- msr elr_el3, lr
+ 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, \ep
+ eret
+
+1:
+ /*
+ * The next lower exception level is AArch32, 32bit EL2 | HCE |
+ * SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1.
+ */
+ ldr \tmp, =(SCR_EL3_RW_AARCH32 | SCR_EL3_HCE_EN |\
+ SCR_EL3_SMD_DIS | SCR_EL3_RES1 |\
+ SCR_EL3_NS_EN)
+ msr scr_el3, \tmp
+
+ /* Return to AArch32 Hypervisor mode */
+ ldr \tmp, =(SPSR_EL_END_LE | SPSR_EL_ASYN_MASK |\
+ SPSR_EL_IRQ_MASK | SPSR_EL_FIQ_MASK |\
+ SPSR_EL_T_A32 | SPSR_EL_M_AARCH32 |\
+ SPSR_EL_M_HYP)
+ msr spsr_el3, \tmp
+ msr elr_el3, \ep
eret
.endm
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 3a22661..edb842b 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -17,6 +17,95 @@
#define CR_WXN (1 << 19) /* Write Permision Imply XN */
#define CR_EE (1 << 25) /* Exception (Big) Endian */
+#define ES_TO_AARCH64 1
+#define ES_TO_AARCH32 0
+
+/*
+ * SCR_EL3 bits definitions
+ */
+#define SCR_EL3_RW_AARCH64 (1 << 10) /* Next lower level is AArch64 */
+#define SCR_EL3_RW_AARCH32 (0 << 10) /* Lower lowers level are AArch32 */
+#define SCR_EL3_HCE_EN (1 << 8) /* Hypervisor Call enable */
+#define SCR_EL3_SMD_DIS (1 << 7) /* Secure Monitor Call disable */
+#define SCR_EL3_RES1 (3 << 4) /* Reserved, RES1 */
+#define SCR_EL3_NS_EN (1 << 0) /* EL0 and EL1 in Non-scure state */
+
+/*
+ * SPSR_EL3/SPSR_EL2 bits definitions
+ */
+#define SPSR_EL_END_LE (0 << 9) /* Exception Little-endian */
+#define SPSR_EL_DEBUG_MASK (1 << 9) /* Debug exception masked */
+#define SPSR_EL_ASYN_MASK (1 << 8) /* Asynchronous data abort masked */
+#define SPSR_EL_SERR_MASK (1 << 8) /* System Error exception masked */
+#define SPSR_EL_IRQ_MASK (1 << 7) /* IRQ exception masked */
+#define SPSR_EL_FIQ_MASK (1 << 6) /* FIQ exception masked */
+#define SPSR_EL_T_A32 (0 << 5) /* AArch32 instruction set A32 */
+#define SPSR_EL_M_AARCH64 (0 << 4) /* Exception taken from AArch64 */
+#define SPSR_EL_M_AARCH32 (1 << 4) /* Exception taken from AArch32 */
+#define SPSR_EL_M_SVC (0x3) /* Exception taken from SVC mode */
+#define SPSR_EL_M_HYP (0xa) /* Exception taken from HYP mode */
+#define SPSR_EL_M_EL1H (5) /* Exception taken from EL1h mode */
+#define SPSR_EL_M_EL2H (9) /* Exception taken from EL2h mode */
+
+/*
+ * CPTR_EL2 bits definitions
+ */
+#define CPTR_EL2_RES1 (3 << 12 | 0x3ff) /* Reserved, RES1 */
+
+/*
+ * SCTLR_EL2 bits definitions
+ */
+#define SCTLR_EL2_RES1 (3 << 28 | 3 << 22 | 1 << 18 | 1 << 16 |\
+ 1 << 11 | 3 << 4) /* Reserved, RES1 */
+#define SCTLR_EL2_EE_LE (0 << 25) /* Exception Little-endian */
+#define SCTLR_EL2_WXN_DIS (0 << 19) /* Write permission is not XN */
+#define SCTLR_EL2_ICACHE_DIS (0 << 12) /* Instruction cache disabled */
+#define SCTLR_EL2_SA_DIS (0 << 3) /* Stack Alignment Check disabled */
+#define SCTLR_EL2_DCACHE_DIS (0 << 2) /* Data cache disabled */
+#define SCTLR_EL2_ALIGN_DIS (0 << 1) /* Alignment check disabled */
+#define SCTLR_EL2_MMU_DIS (0) /* MMU disabled */
+
+/*
+ * CNTHCTL_EL2 bits definitions
+ */
+#define CNTHCTL_EL2_EL1PCEN_EN (1 << 1) /* Physical timer regs accessible */
+#define CNTHCTL_EL2_EL1PCTEN_EN (1 << 0) /* Physical counter accessible */
+
+/*
+ * HCR_EL2 bits definitions
+ */
+#define HCR_EL2_RW_AARCH64 (1 << 31) /* EL1 is AArch64 */
+#define HCR_EL2_RW_AARCH32 (0 << 31) /* Lower levels are AArch32 */
+#define HCR_EL2_HCD_DIS (1 << 29) /* Hypervisor Call disabled */
+
+/*
+ * CPACR_EL1 bits definitions
+ */
+#define CPACR_EL1_FPEN_EN (3 << 20) /* SIMD and FP instruction enabled */
+
+/*
+ * SCTLR_EL1 bits definitions
+ */
+#define SCTLR_EL1_RES1 (3 << 28 | 3 << 22 | 1 << 20 |\
+ 1 << 11) /* Reserved, RES1 */
+#define SCTLR_EL1_UCI_DIS (0 << 26) /* Cache instruction disabled */
+#define SCTLR_EL1_EE_LE (0 << 25) /* Exception Little-endian */
+#define SCTLR_EL1_WXN_DIS (0 << 19) /* Write permission is not XN */
+#define SCTLR_EL1_NTWE_DIS (0 << 18) /* WFE instruction disabled */
+#define SCTLR_EL1_NTWI_DIS (0 << 16) /* WFI instruction disabled */
+#define SCTLR_EL1_UCT_DIS (0 << 15) /* CTR_EL0 access disabled */
+#define SCTLR_EL1_DZE_DIS (0 << 14) /* DC ZVA instruction disabled */
+#define SCTLR_EL1_ICACHE_DIS (0 << 12) /* Instruction cache disabled */
+#define SCTLR_EL1_UMA_DIS (0 << 9) /* User Mask Access disabled */
+#define SCTLR_EL1_SED_EN (0 << 8) /* SETEND instruction enabled */
+#define SCTLR_EL1_ITD_EN (0 << 7) /* IT instruction enabled */
+#define SCTLR_EL1_CP15BEN_DIS (0 << 5) /* CP15 barrier operation disabled */
+#define SCTLR_EL1_SA0_DIS (0 << 4) /* Stack Alignment EL0 disabled */
+#define SCTLR_EL1_SA_DIS (0 << 3) /* Stack Alignment EL1 disabled */
+#define SCTLR_EL1_DCACHE_DIS (0 << 2) /* Data cache disabled */
+#define SCTLR_EL1_ALIGN_DIS (0 << 1) /* Alignment check disabled */
+#define SCTLR_EL1_MMU_DIS (0) /* MMU disabled */
+
#ifndef __ASSEMBLY__
u64 get_page_table_size(void);
@@ -100,7 +189,20 @@ void __asm_invalidate_icache_all(void);
int __asm_flush_l3_cache(void);
void __asm_switch_ttbr(u64 new_ttbr);
-void armv8_switch_to_el2(void);
+/*
+ * Switch from EL3 to EL2 for ARMv8
+ *
+ * @args: For loading 64-bit OS, fdt address.
+ * For loading 32-bit OS, zero.
+ * @mach_nr: For loading 64-bit OS, zero.
+ * For loading 32-bit OS, machine nr
+ * @fdt_addr: For loading 64-bit OS, zero.
+ * For loading 32-bit OS, fdt address.
+ * @entry_point: kernel entry point
+ * @es_flag: execution state flag, ES_TO_AARCH64 or ES_TO_AARCH32
+ */
+void armv8_switch_to_el2(u64 args, u64 mach_nr, u64 fdt_addr,
+ u64 entry_point, u64 es_flag);
void gic_init(void);
void gic_send_sgi(unsigned long sgino);
void wait_for_wakeup(void);
diff --git a/arch/arm/lib/bootm.c b/arch/arm/lib/bootm.c
index e3c9832..59adab8 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -193,7 +193,6 @@ static void do_nonsec_virt_switch(void)
{
smp_kick_all_cpus();
dcache_disable(); /* flush cache before swtiching to EL2 */
- armv8_switch_to_el2();
}
#endif
@@ -284,7 +283,17 @@ static void boot_jump_linux(bootm_headers_t *images, int flag)
if (!fake) {
do_nonsec_virt_switch();
- kernel_entry(images->ft_addr, NULL, NULL, NULL);
+
+ if ((IH_ARCH_DEFAULT == IH_ARCH_ARM64) &&
+ (images->os.arch == IH_ARCH_ARM))
+ armv8_switch_to_el2(0, (u64)gd->bd->bi_arch_number,
+ (u64)images->ft_addr,
+ (u64)images->ep,
+ ES_TO_AARCH32);
+ else
+ armv8_switch_to_el2((u64)images->ft_addr, 0, 0,
+ images->ep,
+ ES_TO_AARCH64);
}
#else
unsigned long machid = gd->bd->bi_arch_number;
diff --git a/common/image-fit.c b/common/image-fit.c
index 6f920da..c28e8fa 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -26,6 +26,7 @@ DECLARE_GLOBAL_DATA_PTR;
#include <u-boot/md5.h>
#include <u-boot/sha1.h>
#include <u-boot/sha256.h>
+#include <generated/autoconf.h>
/*****************************************************************************/
/* New uImage format routines */
@@ -1160,11 +1161,18 @@ int fit_image_check_os(const void *fit, int noffset, uint8_t os)
int fit_image_check_arch(const void *fit, int noffset, uint8_t arch)
{
uint8_t image_arch;
+ int aarch32_support = 0;
+
+#ifdef CONFIG_ARM64_SUPPORT_AARCH32
+ aarch32_support = 1;
+#endif
if (fit_image_get_arch(fit, noffset, &image_arch))
return 0;
return (arch == image_arch) ||
- (arch == IH_ARCH_I386 && image_arch == IH_ARCH_X86_64);
+ (arch == IH_ARCH_I386 && image_arch == IH_ARCH_X86_64) ||
+ (arch == IH_ARCH_ARM64 && image_arch == IH_ARCH_ARM &&
+ aarch32_support);
}
/**
@@ -1593,6 +1601,9 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
int type_ok, os_ok;
ulong load, data, len;
uint8_t os;
+#ifndef USE_HOSTCC
+ uint8_t os_arch;
+#endif
const char *prop_name;
int ret;
@@ -1676,6 +1687,12 @@ int fit_image_load(bootm_headers_t *images, ulong addr,
return -ENOEXEC;
}
#endif
+
+#ifndef USE_HOSTCC
+ fit_image_get_arch(fit, noffset, &os_arch);
+ images->os.arch = os_arch;
+#endif
+
if (image_type == IH_TYPE_FLATDT &&
!fit_image_check_comp(fit, noffset, IH_COMP_NONE)) {
puts("FDT image is compressed");
--
2.1.0.27.g96db324
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