Am 03.06.2016 um 11:31 schrieb Huan Wang alison.wang@nxp.com:
On 03.06.16 05:11, Huan Wang wrote:
On 26.05.16 10:41, Alison Wang wrote:
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@nxp.com Signed-off-by: Alison Wang alison.wang@nxp.com Signed-off-by: Chenhui Zhao chenhui.zhao@nxp.com
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/transition.S | 8 +- arch/arm/include/asm/macro.h | 174
++++++++++++++++++++++++++++++-
arch/arm/include/asm/system.h | 118 ++++++++++++++++++++++++++- arch/arm/lib/bootm.c | 19 ++++- common/image-fit.c | 14 +++- 6 files changed, 287 insertions(+), 52 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 729b181..794cb4f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -77,6 +77,12 @@ 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 && !CONFIG_THUNDERX
I don't think that works. In Kconfig you need to omit the CONFIG_
parts.
It's "ARM64" also, not "CONFIG_ARM64".
Please just try to run a local make defconfig on the thunderx reference system and see whether it includes the option or not.
[Alison Wang] Yes, I missed it. Will change in the next version.
- help
This ARM64 system supports AArch32 execution state.choice prompt "Target select" default TARGET_HIKEY diff --git a/arch/arm/cpu/armv8/transition.S b/arch/arm/cpu/armv8/transition.S index 253a39b..417e8b4 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, x1, x2, 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, x1, x2, 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..dd2c510 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 +138,18 @@ 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
- @arch: machine nr
- @ftaddr: fdt address
- @flag: The execution state flag for lower exception
level, ES_TO_AARCH64 or ES_TO_AARCH32- */
+.macro armv8_switch_to_el2_m, ep, arch, ftaddr, flag, xreg5
You're never really using the arch and ftaddr arguments. Just describe in the macro header that they need to be in x1 and x2 respectively and leave them out of the argument list for the macro.
[Alison Wang] Do you mean rename arch and ftaddr to x1 and x2 here?
I mean omit arch and ftaddr from the macro arguments and instead mention that x1 and x2 get passed as x1 and x2 to the guest and are usually "ftaddr" and "arch".
Also it would make the code more consistent to always use ep.
[Alison Wang] I don't think arch and ftaddr can be removed from the macro arguments in the current code. For 32-bit kernel startup entry point, the requirements are: r0 = 0, r1 = machine nr, r2 = atags or dtb pointer.
You don't refer to them, so they can be removed. Don't remove them from the function prototype - only from the macro.
Or if you find it too confusing to read then, pass a struct that contains ep, x0, x1, x2 and load the values from there.
Alex