[bootwrapper PATCH v2 07/13] Rework common init C code

Mark Rutland
2022-01-14T11:00:06Z

In init_platform() we initialize a UART and announce the presence of the
bootwrapper to the world. We do this relatively late in the boot-flow,
and prior to this will silently ignore errors (e.g. in gic_secure_init).

To make it possible to provide improved diagnostics, and to allow us to
move more initialization into C, this patch reworks the init code to
call a C function earlier, where we can announce the presence of the
boot-wrapper and perform other initialization.

In subsequent patches this will be expanded with more CPU
initialization.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
Makefile.am | 2 +-
arch/aarch32/boot.S | 5 +++++
arch/aarch64/boot.S | 4 ++++
common/boot.c | 4 ----
common/init.c | 24 ++++++++++++++++++++++++
common/platform.c | 12 +++++++-----
include/platform.h | 17 +++++++++++++++++
7 files changed, 58 insertions(+), 10 deletions(-)
create mode 100644 common/init.c
create mode 100644 include/platform.h

diff --git a/Makefile.am b/Makefile.am
index f941b07..0651c38 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -34,7 +34,7 @@ endif
PSCI_CPU_OFF := 0x84000002

COMMON_SRC := common/
-COMMON_OBJ := boot.o bakery_lock.o platform.o lib.o
+COMMON_OBJ := boot.o bakery_lock.o platform.o lib.o init.o

ARCH_OBJ := boot.o stack.o utils.o

diff --git a/arch/aarch32/boot.S b/arch/aarch32/boot.S
index 00c432d..ee073ea 100644
--- a/arch/aarch32/boot.S
+++ b/arch/aarch32/boot.S
@@ -48,6 +48,9 @@ ASM_FUNC(_start)
mov r0, #1
ldr r1, =flag_no_el3
str r0, [r1]
+
+ bl cpu_init_bootwrapper
+
b start_no_el3

_switch_monitor:
@@ -71,6 +74,8 @@ _monitor:
ldr r0, =COUNTER_FREQ
mcr p15, 0, r0, c14, c0, 0 @ CNTFRQ

+ bl cpu_init_bootwrapper
+
bl gic_secure_init

/* Initialise boot method */
diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
index 45a0367..17b4a75 100644
--- a/arch/aarch64/boot.S
+++ b/arch/aarch64/boot.S
@@ -141,6 +141,8 @@ reset_at_el3:
b.eq err_invalid_id
bl setup_stack

+ bl cpu_init_bootwrapper
+
bl gic_secure_init

b start_el3
@@ -181,6 +183,8 @@ reset_no_el3:
ldr x1, =flag_no_el3
str w0, [x1]

+ bl cpu_init_bootwrapper
+
b start_no_el3

err_invalid_id:
diff --git a/common/boot.c b/common/boot.c
index c74d34c..29d53a4 100644
--- a/common/boot.c
+++ b/common/boot.c
@@ -12,8 +12,6 @@
extern unsigned long entrypoint;
extern unsigned long dtb;

-void init_platform(void);
-
void __noreturn jump_kernel(unsigned long address,
unsigned long a0,
unsigned long a1,
@@ -62,8 +60,6 @@ void __noreturn first_spin(unsigned int cpu, unsigned long *mbox,
unsigned long invalid)
{
if (cpu == 0) {
- init_platform();
-
*mbox = (unsigned long)&entrypoint;
sevl();
spin(mbox, invalid, 1);
diff --git a/common/init.c b/common/init.c
new file mode 100644
index 0000000..9c471c9
--- /dev/null
+++ b/common/init.c
@@ -0,0 +1,24 @@
+/*
+ * init.c - common boot-wrapper initialization
+ *
+ * Copyright (C) 2021 ARM Limited. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE.txt file.
+ */
+#include <cpu.h>
+#include <platform.h>
+
+static void announce_bootwrapper(void)
+{
+ print_string("Boot-wrapper v0.2\r\n\r\n");
+}
+
+void cpu_init_bootwrapper(void)
+{
+ if (this_cpu_logical_id() == 0) {
+ init_uart();
+ announce_bootwrapper();
+ init_platform();
+ }
+}
diff --git a/common/platform.c b/common/platform.c
index d11f568..47bf547 100644
--- a/common/platform.c
+++ b/common/platform.c
@@ -1,5 +1,5 @@
/*
- * platform.c - code to initialise everything required when first booting.
+ * platform.c - Platform initialization and I/O.
*
* Copyright (C) 2015 ARM Limited. All rights reserved.
*
@@ -7,6 +7,7 @@
* found in the LICENSE.txt file.
*/

+#include <cpu.h>
#include <stdint.h>

#include <asm/io.h>
@@ -30,7 +31,7 @@
#define V2M_SYS(reg) ((void *)SYSREGS_BASE + V2M_SYS_##reg)
#endif

-static void print_string(const char *str)
+void print_string(const char *str)
{
uint32_t flags;

@@ -47,7 +48,7 @@ static void print_string(const char *str)
}
}

-void init_platform(void)
+void init_uart(void)
{
/*
* UART initialisation (38400 8N1)
@@ -58,9 +59,10 @@ void init_platform(void)
raw_writel(0x70, PL011(UART_LCR_H));
/* Enable the UART, TXen and RXen */
raw_writel(0x301, PL011(UARTCR));
+}

- print_string("Boot-wrapper v0.2\r\n\r\n");
-
+void init_platform(void)
+{
#ifdef SYSREGS_BASE
/*
* CLCD output site MB
diff --git a/include/platform.h b/include/platform.h
new file mode 100644
index 0000000..e5248e1
--- /dev/null
+++ b/include/platform.h
@@ -0,0 +1,17 @@
+/*
+ * include/platform.h - Platform initialization and I/O.
+ *
+ * Copyright (C) 2021 ARM Limited. All rights reserved.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE.txt file.
+ */
+#ifndef __PLATFORM_H
+#define __PLATFORM_H
+
+void print_string(const char *str);
+void init_uart(void);
+
+void init_platform(void);
+
+#endif /* __PLATFORM_H */
--
2.30.2