[PATCH v2 14/16] x86: zboot: Allow overriding the command line

[Simon Glass <sjg@chromium.org>]

When booting Chrome OS images the command line is stored separately
from the kernel. Add a way to specify this address so that images boot
correctly.

Also add comments to the zimage.h header.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
---

(no changes since v1)

 arch/x86/include/asm/zimage.h | 30 +++++++++++++++++++++++++++++-
 arch/x86/lib/bootm.c          |  2 +-
 arch/x86/lib/zimage.c         | 21 ++++++++++++++++-----
 3 files changed, 46 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/zimage.h b/arch/x86/include/asm/zimage.h
index 80e128ccf36..64c0e6e857b 100644
--- a/arch/x86/include/asm/zimage.h
+++ b/arch/x86/include/asm/zimage.h
@@ -30,10 +30,38 @@
 #define BZIMAGE_LOAD_ADDR  0x100000
 #define ZIMAGE_LOAD_ADDR   0x10000
 
+/**
+ * load_zimage() - Load a zImage or bzImage
+ *
+ * This copies an image into the standard location ready for setup
+ *
+ * @image: Address of image to load
+ * @kernel_size: Size of kernel including setup block (or 0 if the kernel is
+ *	new enough to have a 'syssize' value)
+ * @load_addressp: Returns the address where the kernel has been loaded
+ * @return address of setup block, or NULL if something went wrong
+ */
 struct boot_params *load_zimage(char *image, unsigned long kernel_size,
 				ulong *load_addressp);
+
+/**
+ * setup_zimage() - Set up a loaded zImage or bzImage ready for booting
+ *
+ * @setup_base: Pointer to the boot parameters, typically at address
+ *	DEFAULT_SETUP_BASE
+ * @cmd_line: Place to put the command line, or NULL to use the one in the setup
+ *	block
+ * @initrd_addr: Address of the initial ramdisk, or 0 if none
+ * @initrd_size: Size of the initial ramdisk, or 0 if none
+ * @load_address: Address where the bzImage is moved before booting, either
+ *	BZIMAGE_LOAD_ADDR or ZIMAGE_LOAD_ADDR
+ * @cmdline_force: Address of 'override' command line, or 0 to use the one in
+ *	the *	setup block
+ * @return 0 (always)
+ */
 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
-		 unsigned long initrd_addr, unsigned long initrd_size);
+		 ulong initrd_addr, ulong initrd_size, ulong cmdline_force);
+
 void setup_video(struct screen_info *screen_info);
 void setup_efi_info(struct efi_info *efi_info);
 
diff --git a/arch/x86/lib/bootm.c b/arch/x86/lib/bootm.c
index 1198a52ecac..da6b8ce1ec1 100644
--- a/arch/x86/lib/bootm.c
+++ b/arch/x86/lib/bootm.c
@@ -136,7 +136,7 @@ static int boot_prep_linux(bootm_headers_t *images)
 	printf("Setup at %#08lx\n", images->ep);
 	ret = setup_zimage((void *)images->ep, cmd_line_dest,
 			0, images->rd_start,
-			images->rd_end - images->rd_start);
+			images->rd_end - images->rd_start, 0);
 
 	if (ret) {
 		printf("## Setting up boot parameters failed ...\n");
diff --git a/arch/x86/lib/zimage.c b/arch/x86/lib/zimage.c
index aacfffcee7d..8c3d677debc 100644
--- a/arch/x86/lib/zimage.c
+++ b/arch/x86/lib/zimage.c
@@ -56,6 +56,8 @@
  *	BZIMAGE_LOAD_ADDR or ZIMAGE_LOAD_ADDR
  * @base_ptr: Pointer to the boot parameters, typically at address
  *	DEFAULT_SETUP_BASE
+ * @cmdline: Address of 'override' command line, or 0 to use the one in the
+ *	setup block
  */
 struct zboot_state {
 	ulong bzimage_addr;
@@ -64,6 +66,7 @@ struct zboot_state {
 	ulong initrd_size;
 	ulong load_address;
 	struct boot_params *base_ptr;
+	ulong cmdline;
 } state;
 
 enum {
@@ -284,7 +287,7 @@ struct boot_params *load_zimage(char *image, unsigned long kernel_size,
 }
 
 int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
-		 unsigned long initrd_addr, unsigned long initrd_size)
+		 ulong initrd_addr, ulong initrd_size, ulong cmdline_force)
 {
 	struct setup_header *hdr = &setup_base->hdr;
 	int bootproto = get_boot_protocol(hdr, false);
@@ -325,7 +328,10 @@ int setup_zimage(struct boot_params *setup_base, char *cmd_line, int auto_boot,
 		}
 
 		/* build command line at COMMAND_LINE_OFFSET */
-		build_command_line(cmd_line, auto_boot);
+		if (cmdline_force)
+			strcpy(cmd_line, (char *)cmdline_force);
+		else
+			build_command_line(cmd_line, auto_boot);
 	}
 
 	if (IS_ENABLED(CONFIG_INTEL_MID) && bootproto >= 0x0207)
@@ -384,6 +390,8 @@ static int do_zboot_start(struct cmd_tbl *cmdtp, int flag, int argc,
 		state.load_address = state.bzimage_addr;
 		state.bzimage_addr = 0;
 	}
+	if (argc >= 7)
+		state.cmdline = simple_strtoul(argv[6], NULL, 16);
 
 	return 0;
 }
@@ -427,7 +435,8 @@ static int do_zboot_setup(struct cmd_tbl *cmdtp, int flag, int argc,
 		return CMD_RET_FAILURE;
 	}
 	ret = setup_zimage(base_ptr, (char *)base_ptr + COMMAND_LINE_OFFSET,
-			   0, state.initrd_addr, state.initrd_size);
+			   0, state.initrd_addr, state.initrd_size,
+			   state.cmdline);
 	if (ret) {
 		puts("Setting up boot parameters failed ...\n");
 		return CMD_RET_FAILURE;
@@ -627,7 +636,7 @@ int do_zboot_dump(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
 	if (hdr->cmd_line_ptr) {
 		printf("   ");
 		/* Use puts() to avoid limits from CONFIG_SYS_PBSIZE */
-		puts((char *)hdr->cmd_line_ptr);
+		puts((char *)(ulong)hdr->cmd_line_ptr);
 		printf("\n");
 	}
 	print_num("Initrd addr max", hdr->initrd_addr_max);
@@ -707,7 +716,7 @@ int do_zboot_parent(struct cmd_tbl *cmdtp, int flag, int argc,
 
 U_BOOT_CMDREP_COMPLETE(
 	zboot, 8, do_zboot_parent, "Boot bzImage",
-	"[addr] [size] [initrd addr] [initrd size] [setup]\n"
+	"[addr] [size] [initrd addr] [initrd size] [setup] [cmdline]\n"
 	"      addr -        The optional starting address of the bzimage.\n"
 	"                    If not set it defaults to the environment\n"
 	"                    variable \"fileaddr\".\n"
@@ -717,6 +726,8 @@ U_BOOT_CMDREP_COMPLETE(
 	"      initrd size - The size of the initrd image to use, if any.\n"
 	"      setup -       The address of the kernel setup region, if this\n"
 	"                    is not at addr\n"
+	"      cmdline -     The address of the kernel command line, to\n"
+	"                    override U-Boot's normal cmdline generation\n"
 	"\n"
 	"Sub-commands to do part of the zboot sequence:\n"
 	"\tstart [addr [arg ...]] - specify arguments\n"
-- 
2.28.0.402.g5ffc5be6b7-goog