CHROMIUM: reunify boot_kernel

During the code migration to the redesigned vboot_reference API, the
boot_kernel (formerly named load_kernel_helper) was divided and its
private functions were taken out to keep U-Boot compilable

$ git log --oneline -3 -- lib/chromeos/load_kernel_helper.c
6cdb577 CHROMIUM: remove codes based on deprecated API of vboot_reference
29c5f74 CHROMIUM: Separate cmdline update part from load_kernel_helper library.
f853479 CHROMIUM: Separate the pre-boot FDT update part from load_kernel_helper library.

The commit 29c5f74 and f853479 took out the private functions for
updating kernel command line and embedding crossystem data into a device
tree. The functions are the guts of boot_kernel and serve no purpose
other than helping boot kernel.

In fact, if you diff load_kernel_helper and boot_kernel, you will find
they are virtually identical, except that functions based on deprecated
APIs of vboot_reference are removed in boot_kernel.

As the code migration has been completed, it is time for the private
functions to reunite with the boot_kernel.

BUG=chromium-os:16542
TEST=boot on Aebl

Change-Id: I6512d7a5197c41df7a2e9cc5d90c40be87b468b0
Reviewed-on: http://gerrit.chromium.org/gerrit/4573
Reviewed-by: Che-Liang Chiou <clchiou@chromium.org>
Tested-by: Che-Liang Chiou <clchiou@chromium.org>

6 files changed, 243 insertions, 159 deletions

diff --git a/lib/chromeos/Makefile b/lib/chromeos/Makefile
index e21429a399..751bc42df2 100644
--- a/lib/chromeos/Makefile
+++ b/lib/chromeos/Makefile
@@ -12,12 +12,11 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)libchromeos.a
 
-COBJS-$(CONFIG_CHROMEOS) += cmdline_updater.o
+COBJS-$(CONFIG_CHROMEOS) += boot_kernel.o
 COBJS-$(CONFIG_CHROMEOS) += crossystem_data.o
 COBJS-$(CONFIG_CHROMEOS) += fdt_decode.o
 COBJS-$(CONFIG_CHROMEOS) += firmware_storage_spi.o
 COBJS-$(CONFIG_CHROMEOS) += memory_wipe.o
-COBJS-$(CONFIG_CHROMEOS) += preboot_fdt_update.o
 
 # TODO(sjg): This MMC code is not needed as yet, and needs slight changes
 # to build now
diff --git a/lib/chromeos/boot_kernel.c b/lib/chromeos/boot_kernel.c
new file mode 100644
index 0000000000..16cd1dc364
--- /dev/null
+++ b/lib/chromeos/boot_kernel.c
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ */
+
+#include <common.h>
+#include <part.h>
+#include <chromeos/boot_kernel.h>
+#include <chromeos/common.h>
+#include <chromeos/crossystem_data.h>
+
+#include <load_kernel_fw.h>
+#include <vboot_api.h>
+
+#define PREFIX "boot_kernel: "
+
+/*
+ * We uses a static variable to communicate with fit_update_fdt_before_boot().
+ * For more information, please see commit log.
+ */
+static crossystem_data_t *g_crossystem_data = NULL;
+
+/* defined in common/cmd_bootm.c */
+int do_bootm(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[]);
+
+/* Maximum kernel command-line size */
+#define CROS_CONFIG_SIZE	4096
+
+/* Size of the x86 zeropage table */
+#define CROS_PARAMS_SIZE	4096
+
+/* Extra buffer to string replacement */
+#define EXTRA_BUFFER		4096
+
+/**
+ * This loads kernel command line from the buffer that holds the loaded kernel
+ * image. This function calculates the address of the command line from the
+ * bootloader address.
+ *
+ * @param bootloader_address is the address of the bootloader in the buffer
+ * @return kernel config address
+ */
+static char *get_kernel_config(char *bootloader_address)
+{
+	/* Use the bootloader address to find the kernel config location. */
+	return bootloader_address - CROS_PARAMS_SIZE - CROS_CONFIG_SIZE;
+}
+
+static uint32_t get_dev_num(const block_dev_desc_t *dev)
+{
+	return dev->dev;
+}
+
+/* assert(0 <= val && val < 99); sprintf(dst, "%u", val); */
+static char *itoa(char *dst, int val)
+{
+	if (val > 9)
+		*dst++ = '0' + val / 10;
+	*dst++ = '0' + val % 10;
+	return dst;
+}
+
+/* copied from x86 bootstub code; sprintf(dst, "%02x", val) */
+static void one_byte(char *dst, uint8_t val)
+{
+	dst[0] = "0123456789abcdef"[(val >> 4) & 0x0F];
+	dst[1] = "0123456789abcdef"[val & 0x0F];
+}
+
+/* copied from x86 bootstub code; display a GUID in canonical form */
+static char *emit_guid(char *dst, uint8_t *guid)
+{
+	one_byte(dst, guid[3]); dst += 2;
+	one_byte(dst, guid[2]); dst += 2;
+	one_byte(dst, guid[1]); dst += 2;
+	one_byte(dst, guid[0]); dst += 2;
+	*dst++ = '-';
+	one_byte(dst, guid[5]); dst += 2;
+	one_byte(dst, guid[4]); dst += 2;
+	*dst++ = '-';
+	one_byte(dst, guid[7]); dst += 2;
+	one_byte(dst, guid[6]); dst += 2;
+	*dst++ = '-';
+	one_byte(dst, guid[8]); dst += 2;
+	one_byte(dst, guid[9]); dst += 2;
+	*dst++ = '-';
+	one_byte(dst, guid[10]); dst += 2;
+	one_byte(dst, guid[11]); dst += 2;
+	one_byte(dst, guid[12]); dst += 2;
+	one_byte(dst, guid[13]); dst += 2;
+	one_byte(dst, guid[14]); dst += 2;
+	one_byte(dst, guid[15]); dst += 2;
+	return dst;
+}
+
+/**
+ * This replaces:
+ *   %D -> device number
+ *   %P -> partition number
+ *   %U -> GUID
+ * in kernel command line.
+ *
+ * For example:
+ *   ("root=/dev/sd%D%P", 2, 3)      -> "root=/dev/sdc3"
+ *   ("root=/dev/mmcblk%Dp%P", 0, 5) -> "root=/dev/mmcblk0p5".
+ *
+ * @param src - input string
+ * @param devnum - device number of the storage device we will mount
+ * @param partnum - partition number of the root file system we will mount
+ * @param guid - guid of the kernel partition
+ * @param dst - output string; a copy of [src] with special characters replaced
+ */
+static void update_cmdline(char *src, int devnum, int partnum, uint8_t *guid,
+		char *dst)
+{
+	int c;
+
+	// sanity check on inputs
+	if (devnum < 0 || devnum > 25 || partnum < 1 || partnum > 99) {
+		VBDEBUG(PREFIX "insane input: %d, %d\n", devnum, partnum);
+		devnum = 0;
+		partnum = 3;
+	}
+
+	while ((c = *src++)) {
+		if (c != '%') {
+			*dst++ = c;
+			continue;
+		}
+
+		switch ((c = *src++)) {
+		case '\0':
+			/* input ends in '%'; is it not well-formed? */
+			src--;
+			break;
+		case 'D':
+			/*
+			 * TODO: Do we have any better way to know whether %D
+			 * is replaced by a letter or digits? So far, this is
+			 * done by a rule of thumb that if %D is followed by a
+			 * 'p' character, then it is replaced by digits.
+			 */
+			if (*src == 'p')
+				dst = itoa(dst, devnum);
+			else
+				*dst++ = 'a' + devnum;
+			break;
+		case 'P':
+			dst = itoa(dst, devnum);
+			break;
+		case 'U':
+			dst = emit_guid(dst, guid);
+			break;
+		default:
+			*dst++ = '%';
+			*dst++ = c;
+			break;
+		}
+	}
+
+	*dst = '\0';
+}
+
+/**
+ * This boots kernel specified in [kparmas].
+ *
+ * @param kparams	kparams returned from VbSelectAndLoadKernel()
+ * @param cdata		crossystem data pointer
+ * @return LOAD_KERNEL_INVALID if it fails to boot; otherwise it never returns
+ *         to its caller
+ */
+int boot_kernel(VbSelectAndLoadKernelParams *kparams, crossystem_data_t *cdata)
+{
+	char cmdline_buf[CROS_CONFIG_SIZE + EXTRA_BUFFER];
+	char cmdline_out[CROS_CONFIG_SIZE + EXTRA_BUFFER];
+	char load_address[32];
+	char *argv[2] = {"bootm", load_address};
+	char *cmdline;
+
+	/*
+	 * casting bootloader_address of uint64_t type to uintptr_t before
+	 * further casting it to char * to avoid compiler warning "cast to
+	 * pointer from integer of different size" on 32-bit address machine.
+	 */
+	cmdline = get_kernel_config((char *)
+			(uintptr_t)kparams->bootloader_address);
+	strncpy(cmdline_buf, cmdline, CROS_CONFIG_SIZE);
+
+	/* if we have init bootargs, append it */
+	if ((cmdline = getenv("bootargs"))) {
+		strcat(cmdline_buf, " ");
+		strncat(cmdline_buf, cmdline, EXTRA_BUFFER - 1);
+	}
+
+	VBDEBUG(PREFIX "cmdline before update: %s\n", cmdline_buf);
+
+	update_cmdline(cmdline_buf,
+			get_dev_num(kparams->disk_handle),
+			kparams->partition_number + 1,
+			kparams->partition_guid,
+			cmdline_out);
+
+	setenv("bootargs", cmdline_out);
+	VBDEBUG(PREFIX "cmdline after update:  %s\n", getenv("bootargs"));
+
+	g_crossystem_data = cdata;
+
+	sprintf(load_address, "0x%p", kparams->kernel_buffer);
+	do_bootm(NULL, 0, sizeof(argv)/sizeof(*argv), argv);
+
+	VBDEBUG(PREFIX "failed to boot; is kernel broken?\n");
+	return LOAD_KERNEL_INVALID;
+}
+
+/*
+ * This function does the last chance FDT update before booting to kernel.
+ * Currently we modify the FDT by embedding crossystem data. So before
+ * calling bootm(), g_crossystem_data should be set.
+ */
+int fit_update_fdt_before_boot(char *fdt, ulong *new_size)
+{
+	uint32_t ns;
+
+	if (!g_crossystem_data) {
+		VBDEBUG(PREFIX "warning: g_crossystem_data is NULL\n");
+		return 0;
+	}
+
+	if (crossystem_data_embed_into_fdt(g_crossystem_data, fdt, &ns)) {
+		VBDEBUG(PREFIX "crossystem_data_embed_into_fdt() failed\n");
+		return 0;
+	}
+
+	*new_size = ns;
+	return 0;
+}
diff --git a/lib/chromeos/cmdline_updater.c b/lib/chromeos/cmdline_updater.c
deleted file mode 100644
index d431adfb7d..0000000000
--- a/lib/chromeos/cmdline_updater.c
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- *
- * Alternatively, this software may be distributed under the terms of the
- * GNU General Public License ("GPL") version 2 as published by the Free
- * Software Foundation.
- */
-
-#include <common.h>
-#include <chromeos/common.h>
-#include <chromeos/cmdline_updater.h>
-
-#define PREFIX "cmdline_updater: "
-
-/* assert(0 <= val && val < 99); sprintf(dst, "%u", val); */
-static char *itoa(char *dst, int val)
-{
-	if (val > 9)
-		*dst++ = '0' + val / 10;
-	*dst++ = '0' + val % 10;
-	return dst;
-}
-
-/* copied from x86 bootstub code; sprintf(dst, "%02x", val) */
-static void one_byte(char *dst, uint8_t val)
-{
-	dst[0] = "0123456789abcdef"[(val >> 4) & 0x0F];
-	dst[1] = "0123456789abcdef"[val & 0x0F];
-}
-
-/* copied from x86 bootstub code; display a GUID in canonical form */
-static char *emit_guid(char *dst, uint8_t *guid)
-{
-	one_byte(dst, guid[3]); dst += 2;
-	one_byte(dst, guid[2]); dst += 2;
-	one_byte(dst, guid[1]); dst += 2;
-	one_byte(dst, guid[0]); dst += 2;
-	*dst++ = '-';
-	one_byte(dst, guid[5]); dst += 2;
-	one_byte(dst, guid[4]); dst += 2;
-	*dst++ = '-';
-	one_byte(dst, guid[7]); dst += 2;
-	one_byte(dst, guid[6]); dst += 2;
-	*dst++ = '-';
-	one_byte(dst, guid[8]); dst += 2;
-	one_byte(dst, guid[9]); dst += 2;
-	*dst++ = '-';
-	one_byte(dst, guid[10]); dst += 2;
-	one_byte(dst, guid[11]); dst += 2;
-	one_byte(dst, guid[12]); dst += 2;
-	one_byte(dst, guid[13]); dst += 2;
-	one_byte(dst, guid[14]); dst += 2;
-	one_byte(dst, guid[15]); dst += 2;
-	return dst;
-}
-
-/* This replaces %D, %P, and %U in kernel command line */
-void update_cmdline(char *src, int devnum, int partnum, uint8_t *guid,
-		char *dst)
-{
-	int c;
-
-	// sanity check on inputs
-	if (devnum < 0 || devnum > 25 || partnum < 1 || partnum > 99) {
-		VBDEBUG(PREFIX "insane input: %d, %d\n", devnum, partnum);
-		devnum = 0;
-		partnum = 3;
-	}
-
-	while ((c = *src++)) {
-		if (c != '%') {
-			*dst++ = c;
-			continue;
-		}
-
-		switch ((c = *src++)) {
-		case '\0':
-			/* input ends in '%'; is it not well-formed? */
-			src--;
-			break;
-		case 'D':
-			/*
-			 * TODO: Do we have any better way to know whether %D
-			 * is replaced by a letter or digits? So far, this is
-			 * done by a rule of thumb that if %D is followed by a
-			 * 'p' character, then it is replaced by digits.
-			 */
-			if (*src == 'p')
-				dst = itoa(dst, devnum);
-			else
-				*dst++ = 'a' + devnum;
-			break;
-		case 'P':
-			dst = itoa(dst, devnum);
-			break;
-		case 'U':
-			dst = emit_guid(dst, guid);
-			break;
-		default:
-			*dst++ = '%';
-			*dst++ = c;
-			break;
-		}
-	}
-
-	*dst = '\0';
-}
diff --git a/lib/chromeos/preboot_fdt_update.c b/lib/chromeos/preboot_fdt_update.c
deleted file mode 100644
index 06615aebba..0000000000
--- a/lib/chromeos/preboot_fdt_update.c
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- *
- * Alternatively, this software may be distributed under the terms of the
- * GNU General Public License ("GPL") version 2 as published by the Free
- * Software Foundation.
- */
-
-#include <common.h>
-#include <chromeos/common.h>
-#include <chromeos/crossystem_data.h>
-
-#define PREFIX "preboot_fdt_update: "
-
-/*
- * We uses a static variable to communicate with fit_update_fdt_before_boot().
- * For more information, please see commit log.
- */
-static crossystem_data_t *g_crossystem_data = NULL;
-
-void set_crossystem_data(crossystem_data_t *cdata)
-{
-	g_crossystem_data = cdata;
-}
-
-int fit_update_fdt_before_boot(char *fdt, ulong *new_size)
-{
-	uint32_t ns;
-
-	if (!g_crossystem_data) {
-		VBDEBUG(PREFIX "warning: g_crossystem_data is NULL\n");
-		return 0;
-	}
-
-	if (crossystem_data_embed_into_fdt(g_crossystem_data, fdt, &ns)) {
-		VBDEBUG(PREFIX "crossystem_data_embed_into_fdt() failed\n");
-		return 0;
-	}
-
-	*new_size = ns;
-	return 0;
-}
diff --git a/lib/vboot/Makefile b/lib/vboot/Makefile
index 6e0b9c9922..b209529113 100644
--- a/lib/vboot/Makefile
+++ b/lib/vboot/Makefile
@@ -12,14 +12,11 @@ include $(TOPDIR)/config.mk
 
 LIB	= $(obj)libvboot.a
 
-COBJS-$(CONFIG_CHROMEOS_VBOOT) += boot_kernel.o
 COBJS-$(CONFIG_CHROMEOS_VBOOT) += bootstub_entry.o
 COBJS-$(CONFIG_CHROMEOS_VBOOT) += firmware_cache.o
 COBJS-$(CONFIG_CHROMEOS_VBOOT) += global_data.o
 COBJS-$(CONFIG_CHROMEOS_VBOOT) += main_entry.o
 
-COBJS-$(CONFIG_CHROMEOS_TWOSTOP) += boot_kernel.o
-
 COBJS	:= $(COBJS-y)
 OBJS	:= $(addprefix $(obj),$(COBJS))
 
diff --git a/lib/vboot/main_entry.c b/lib/vboot/main_entry.c
index c6b67d5ba8..66eff92987 100644
--- a/lib/vboot/main_entry.c
+++ b/lib/vboot/main_entry.c
@@ -9,8 +9,8 @@
  */
 
 #include <common.h>
+#include <chromeos/boot_kernel.h>
 #include <chromeos/common.h>
-#include <vboot/boot_kernel.h>
 #include <vboot/entry_points.h>
 #include <vboot/global_data.h>
 #include <vboot_api.h>