Introduce 'stdout' interface
"plat_console" is a build parameter that specifies the console driver
to be used for the given platform. This parameter has been overridden
for all VM toolchains, passing in a HVC-based driver instead.
To keep "plat_console" tied to the platform, introduce "stdout",
which is a platform-agnostic abstraction of an output stream accepting
chars. The default implementation, used by the hypervisor, forwards the
chars to plat_console_putchar(). The implementation in VM toolchains
passes them to the HVC call.
Change-Id: I2316555d9debdb8ce3de4621f8ddbf4b88164d0f
diff --git a/build/toolchain/embedded.gni b/build/toolchain/embedded.gni
index e824202..4b067e4 100644
--- a/build/toolchain/embedded.gni
+++ b/build/toolchain/embedded.gni
@@ -294,6 +294,9 @@
plat_boot_flow = invoker.boot_flow
plat_console = invoker.console
plat_iommu = invoker.iommu
+ if (defined(invoker.stdout)) {
+ stdout = invoker.stdout
+ }
if (defined(invoker.max_image_size)) {
plat_max_image_size = invoker.max_image_size
}
@@ -344,11 +347,12 @@
"gicr_base_address",
"max_cpus",
"toolchain_args",
+ "console",
])
cpu = "${invoker.cpu}+fp"
boot_flow = "//src/arch/fake:boot_flow"
- console = "//src/arch/aarch64/hftest:console"
iommu = "//src/iommu:absent"
+ stdout = "//src/arch/aarch64/hftest:stdout"
# Nonsense values because they are required but shouldn't be used.
heap_pages = 0
diff --git a/src/arch/aarch64/hftest/console.c b/inc/hf/stdout.h
similarity index 68%
copy from src/arch/aarch64/hftest/console.c
copy to inc/hf/stdout.h
index 4e2f4e8..72a67fa 100644
--- a/src/arch/aarch64/hftest/console.c
+++ b/inc/hf/stdout.h
@@ -1,5 +1,5 @@
/*
- * Copyright 2019 The Hafnium Authors.
+ * Copyright 2020 The Hafnium Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -14,11 +14,11 @@
* limitations under the License.
*/
-#include "hf/plat/console.h"
+#pragma once
-#include "vmapi/hf/call.h"
-
-void plat_console_putchar(char c)
-{
- hf_debug_log(c);
-}
+/**
+ * Print one character to standard output.
+ * This is intentionally called differently from functions in <stdio.h> so as to
+ * avoid clashes when linking against libc.
+ */
+void stdout_putchar(char c);
diff --git a/src/BUILD.gn b/src/BUILD.gn
index 1437908..9c76668 100644
--- a/src/BUILD.gn
+++ b/src/BUILD.gn
@@ -15,6 +15,11 @@
import("//build/image/image.gni")
import("//build/toolchain/platform.gni")
+declare_args() {
+ # Target which implements the standard output interface.
+ stdout = ":stdout"
+}
+
# The hypervisor image.
hypervisor("hafnium") {
deps = [
@@ -99,6 +104,17 @@
]
}
+# Default implementation of stdout which sends the character to the
+# 'plat_console' driver.
+source_set("stdout") {
+ sources = [
+ "stdout.c",
+ ]
+ deps = [
+ plat_console,
+ ]
+}
+
# Debug code that is not specific to a certain image so can be shared.
source_set("dlog") {
sources = [
@@ -107,7 +123,7 @@
deps = [
":std",
- plat_console,
+ stdout,
]
}
diff --git a/src/arch/aarch64/hftest/BUILD.gn b/src/arch/aarch64/hftest/BUILD.gn
index a801bd1..a751b77 100644
--- a/src/arch/aarch64/hftest/BUILD.gn
+++ b/src/arch/aarch64/hftest/BUILD.gn
@@ -75,9 +75,9 @@
]
}
-source_set("console") {
+source_set("stdout") {
sources = [
- "console.c",
+ "stdout.c",
]
deps = [
diff --git a/src/arch/aarch64/hftest/console.c b/src/arch/aarch64/hftest/stdout.c
similarity index 90%
rename from src/arch/aarch64/hftest/console.c
rename to src/arch/aarch64/hftest/stdout.c
index 4e2f4e8..f27f76c 100644
--- a/src/arch/aarch64/hftest/console.c
+++ b/src/arch/aarch64/hftest/stdout.c
@@ -14,11 +14,11 @@
* limitations under the License.
*/
-#include "hf/plat/console.h"
+#include "hf/stdout.h"
#include "vmapi/hf/call.h"
-void plat_console_putchar(char c)
+void stdout_putchar(char c)
{
hf_debug_log(c);
}
diff --git a/src/dlog.c b/src/dlog.c
index 1bda568..1a4bf67 100644
--- a/src/dlog.c
+++ b/src/dlog.c
@@ -19,10 +19,10 @@
#include <stdbool.h>
#include <stddef.h>
-#include "hf/plat/console.h"
#include "hf/spci.h"
#include "hf/spinlock.h"
#include "hf/std.h"
+#include "hf/stdout.h"
/* Keep macro alignment */
/* clang-format off */
@@ -81,7 +81,7 @@
{
dlog_buffer[dlog_buffer_offset] = c;
dlog_buffer_offset = (dlog_buffer_offset + 1) % DLOG_BUFFER_SIZE;
- plat_console_putchar(c);
+ stdout_putchar(c);
}
/**
diff --git a/src/arch/aarch64/hftest/console.c b/src/stdout.c
similarity index 82%
copy from src/arch/aarch64/hftest/console.c
copy to src/stdout.c
index 4e2f4e8..f1c61b7 100644
--- a/src/arch/aarch64/hftest/console.c
+++ b/src/stdout.c
@@ -1,5 +1,5 @@
/*
- * Copyright 2019 The Hafnium Authors.
+ * Copyright 2020 The Hafnium Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -14,11 +14,11 @@
* limitations under the License.
*/
+#include "hf/stdout.h"
+
#include "hf/plat/console.h"
-#include "vmapi/hf/call.h"
-
-void plat_console_putchar(char c)
+void stdout_putchar(char c)
{
- hf_debug_log(c);
+ plat_console_putchar(c);
}
