From 4240723b7850f5274a9629383b2c71d510d6db7b Mon Sep 17 00:00:00 2001
From: qinwei1 <qinwei1@xiaomi.com>
Date: Tue, 28 Feb 2023 15:07:42 +0800
Subject: [PATCH] arm64: add ARCH_EARLY_PRINT support

Summary:
  The aarch64 have EL0~El3 execute level and NS/S (security state),
the NuttX should be execute at EL1 in NS(ARmv8-A) or S(ARmv8-R)
state. but booting NuttX have different ELs and state while with
different platform, if NuttX runing at wrong ELs or state it will
be not normal anymore. So we need to print something in arm64_head.S
to debug this situation.
Enabling this option will need to implement up_earlyserialinit and
up_lowputc functions just you see in qemu, if you not sure,
keeping the option disable.

Signed-off-by: qinwei1 <qinwei1@xiaomi.com>
---
 arch/arm64/Kconfig                                | 13 +++++++++++++
 arch/arm64/src/common/arm64_head.S                | 15 ++++++++-------
 .../arm64/qemu/qemu-armv8a/configs/nsh/defconfig  |  1 +
 .../qemu/qemu-armv8a/configs/nsh_smp/defconfig    |  1 +
 4 files changed, 23 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index c50519b064..cb9c7fcc58 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -64,6 +64,19 @@ config ARCH_HAVE_PSCI
 		maybe not applicable for arm core without PCSI firmware
 		interface implement
 
+config ARCH_EARLY_PRINT
+	bool "arch early print support"
+	default n
+	---help---
+		The aarch64 have EL0~El3 execute level and NS/S (security state),
+		the NuttX should be execute at EL1 in NS(ARmv8-A) or S(ARmv8-R)
+		state. but booting NuttX have different ELs and state while with
+		different platform, if NuttX runing at wrong ELs or state it will
+		be not normal anymore. So we need to print something in arm64_head.S
+		to debug this situation.
+		Enabling this option will need to implement up_earlyserialinit and
+		up_lowputc functions just you see in qemu, if you not sure,
+		keeping the option disable.
 
 config ARCH_CORTEX_A53
 	bool
diff --git a/arch/arm64/src/common/arm64_head.S b/arch/arm64/src/common/arm64_head.S
index ec6cc41f40..82104b7d57 100644
--- a/arch/arm64/src/common/arm64_head.S
+++ b/arch/arm64/src/common/arm64_head.S
@@ -48,7 +48,7 @@
 #define __HEAD_FLAGS            ((__HEAD_FLAG_PAGE_SIZE << 1) | \
                                  (__HEAD_FLAG_PHYS_BASE << 3))
 
-#ifdef CONFIG_DEBUG_FEATURES
+#ifdef CONFIG_ARCH_EARLY_PRINT
 
 #define RODATA_STR(label, msg)                  \
 .pushsection .rodata.str, "aMS", %progbits, 1 ; \
@@ -66,7 +66,7 @@ label:  .asciz msg;                             \
     RODATA_STR(boot_string_##sym, _s)
 #else
 #define PRINT(sym, s)
-#endif /* CONFIG_DEBUG_FEATURES */
+#endif /* CONFIG_ARCH_EARLY_PRINT */
 
 /****************************************************************************
  * Private Functions
@@ -166,7 +166,7 @@ primary_core:
 
     bl     __reset_prep_c
 
-#ifdef CONFIG_DEBUG_FEATURES
+#ifdef CONFIG_ARCH_EARLY_PRINT
     /* Initialize the UART for early print.
      * Should only be called on the boot CPU
      */
@@ -228,8 +228,9 @@ jump_to_c_entry:
 /* Fail-stop */
 
 fail:
-    PRINT(fail, "- Boot failed -\r\n")
-1:      wfe
+    /* Boot failed */
+
+1:  wfe
     b     1b
 
 /* Set the minimum necessary to safely call C code */
@@ -283,7 +284,7 @@ out:
 
     ret   x23
 
-#ifdef CONFIG_DEBUG_FEATURES
+#ifdef CONFIG_ARCH_EARLY_PRINT
 
 /* Print early debug messages.
  * x0: Nul-terminated string to print.
@@ -303,4 +304,4 @@ boot_stage_puts:
 
 .type boot_low_puts, %function;
 
-#endif /* !CONFIG_DEBUG_FEATURES */
+#endif /* !CONFIG_ARCH_EARLY_PRINT */
diff --git a/boards/arm64/qemu/qemu-armv8a/configs/nsh/defconfig b/boards/arm64/qemu/qemu-armv8a/configs/nsh/defconfig
index 06af9b7ea3..821eb9c6c6 100644
--- a/boards/arm64/qemu/qemu-armv8a/configs/nsh/defconfig
+++ b/boards/arm64/qemu/qemu-armv8a/configs/nsh/defconfig
@@ -12,6 +12,7 @@ CONFIG_ARCH_BOARD_QEMU_ARMV8A=y
 CONFIG_ARCH_CHIP="qemu"
 CONFIG_ARCH_CHIP_QEMU=y
 CONFIG_ARCH_CHIP_QEMU_A53=y
+CONFIG_ARCH_EARLY_PRINT=y
 CONFIG_ARCH_INTERRUPTSTACK=4096
 CONFIG_BUILTIN=y
 CONFIG_DEBUG_ASSERTIONS=y
diff --git a/boards/arm64/qemu/qemu-armv8a/configs/nsh_smp/defconfig b/boards/arm64/qemu/qemu-armv8a/configs/nsh_smp/defconfig
index 3540638a72..c7fdd37a93 100644
--- a/boards/arm64/qemu/qemu-armv8a/configs/nsh_smp/defconfig
+++ b/boards/arm64/qemu/qemu-armv8a/configs/nsh_smp/defconfig
@@ -13,6 +13,7 @@ CONFIG_ARCH_BOARD_QEMU_ARMV8A=y
 CONFIG_ARCH_CHIP="qemu"
 CONFIG_ARCH_CHIP_QEMU=y
 CONFIG_ARCH_CHIP_QEMU_A53=y
+CONFIG_ARCH_EARLY_PRINT=y
 CONFIG_ARCH_INTERRUPTSTACK=8192
 CONFIG_BUILTIN=y
 CONFIG_DEBUG_ASSERTIONS=y