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>
---
arch/arm/cpu/armv8/transition.S | 100 ++++++++++++++++++++++++++++++++++++++++
arch/arm/include/asm/system.h | 2 +
arch/arm/lib/bootm.c | 20 +++++++-
common/image-fit.c | 12 ++++-
4 files changed, 131 insertions(+), 3 deletions(-)
diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S
index 253a39b..9d7a17a 100644
--- a/arch/arm/cpu/armv8/transition.S
+++ b/arch/arm/cpu/armv8/transition.S
@@ -21,3 +21,103 @@ ENTRY(armv8_switch_to_el1)
0: ret
1: armv8_switch_to_el1_m x0, x1
ENDPROC(armv8_switch_to_el1)
+
+/*
+ * x0: kernel entry point
+ * x1: machine nr
+ * x2: fdt address
+ */
+ENTRY(armv8_switch_to_el2_aarch32)
+ switch_el x3, 1f, 0f, 0f
+0: ret
+1:
+ mov x7, x0
+ mov x8, x1
+ mov x9, x2
+
+ /* 32bit EL2 | HCE | SMD | RES1 (Bits[5:4]) | Non-secure EL0/EL1 */
+ mov x1, 0x1b1
+ msr scr_el3, x1
+ msr cptr_el3, xzr /* Disable coprocessor traps to EL3 */
+ mov x1, 0x33ff
+ msr cptr_el2, x1 /* Disable coprocessor traps to EL2 */
+
+ /* Initialize Generic Timers */
+ msr cntvoff_el2, xzr
+
+ mov x1, #0x0830
+ movk x1, #0x30c5, lsl #16
+ msr sctlr_el2, x1
+
+ /* Return to AArch32 Hypervisor mode */
+ mov x1, sp
+ msr sp_el2, x1
+ mrs x1, vbar_el3
+ msr vbar_el2, x1 /* Migrate VBAR */
+ mov x1, #0x1da
+ msr spsr_el3, x1
+ msr elr_el3, x7
+
+ mov x0, #0
+ mov x1, x8
+ mov x2, x9
+
+ eret
+ENDPROC(armv8_switch_to_el2_aarch32)
+
+/*
+ * x0: kernel entry point
+ * x1: machine nr
+ * x2: fdt address
+ */
+ENTRY(armv8_switch_to_el1_aarch32)
+ switch_el x3, 0f, 1f, 0f
+0: ret
+1:
+ mov x7, x0
+ mov x8, x1
+ mov x9, x2
+
+ /* Initialize Generic Timers */
+ mrs x0, cnthctl_el2
+ orr x0, x0, #0x3 /* Enable EL1 access to timers */
+ msr cnthctl_el2, x0
+ msr cntvoff_el2, xzr
+
+ /* Initialize MPID/MPIDR registers */
+ mrs x0, midr_el1
+ mrs x1, mpidr_el1
+ msr vpidr_el2, x0
+ msr vmpidr_el2, x1
+
+ /* Disable coprocessor traps */
+ mov x0, #0x33ff
+ msr cptr_el2, x0 /* Disable coprocessor traps to EL2 */
+ msr hstr_el2, xzr /* Disable coprocessor traps to EL2 */
+ mov x0, #3 << 20
+ msr cpacr_el1, x0 /* Enable FP/SIMD at EL1 */
+
+ /* Initialize HCR_EL2 */
+ mov x0, #(0 << 31) /* 32bit EL1 */
+ orr x0, x0, #(1 << 29) /* Disable HVC */
+ msr hcr_el2, x0
+
+ mov x0, #0x0800
+ movk x0, #0x30d0, lsl #16
+ msr sctlr_el1, x0
+
+ /* Return to AArch32 Supervisor mode */
+ mov x0, sp
+ msr sp_el1, x0 /* Migrate SP */
+ mrs x0, vbar_el2
+ msr vbar_el1, x0 /* Migrate VBAR */
+ mov x0, #0x1d3
+ msr spsr_el2, x0
+ msr elr_el2, x7
+
+ mov x0, #0
+ mov x1, x8
+ mov x2, x9
+
+ eret
+ENDPROC(armv8_switch_to_el1_aarch32)
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 9ae890a..bb87cf0 100644
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -102,6 +102,8 @@ void __asm_switch_ttbr(u64 new_ttbr);
void armv8_switch_to_el2(void);
void armv8_switch_to_el1(void);
+void armv8_switch_to_el2_aarch32(u64 entry_point, u64 mach_nr, u64 fdt_addr);
+void armv8_switch_to_el1_aarch32(u64 entry_point, u64 mach_nr, u64 fdt_addr);
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 0838d89..a39c3d2 100644
--- a/arch/arm/lib/bootm.c
+++ b/arch/arm/lib/bootm.c
@@ -286,8 +286,24 @@ static void boot_jump_linux(bootm_headers_t *images, int
flag)
announce_and_cleanup(fake);
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)) {
+ smp_kick_all_cpus();
+ dcache_disable();
+#ifdef CONFIG_ARMV8_SWITCH_TO_EL1
+ armv8_switch_to_el2();
+ armv8_switch_to_el1_aarch32((u64)images->ep,
+ (u64)gd->bd->bi_arch_number,
+ (u64)images->ft_addr);
+#else
+ armv8_switch_to_el2_aarch32((u64)images->ep,
+ (u64)gd->bd->bi_arch_number,
+ (u64)images->ft_addr);
+#endif
+ } else {
+ do_nonsec_virt_switch();
+ kernel_entry(images->ft_addr, NULL, NULL, NULL);
+ }
}
#else
unsigned long machid = gd->bd->bi_arch_number;
diff --git a/common/image-fit.c b/common/image-fit.c
index 25f8a11..2986469 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -1163,7 +1163,8 @@ int fit_image_check_arch(const void *fit, int noffset,
uint8_t arch)
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);
}
/**
@@ -1586,6 +1587,9 @@ 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;
@@ -1669,6 +1673,12 @@ 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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