commit d0dfbf548d0e0f49b33ae22a8fd338231445ecf0
author Simon Glass <sjg@chromium.org> Wed Jul 12 09:04:44 2023 -0600
committer Bin Meng <bmeng@tinylab.org> Mon Jul 17 13:38:35 2023 +0800
tree d96b4694ef64c57c89ce1c7ad5fb81f58664d40a
parent c886557c18956dca5819920fd48d0d250c4b76a1

x86: zimage: Export the function to obtain the cmdline

Allow reading the command line from a zimage, so that it can be recorded
in the bootflow.

Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Signed-off-by: Simon Glass <sjg@chromium.org>

arch/x86/include/asm/zimage.h

diff --git a/arch/x86/include/asm/zimage.h b/arch/x86/include/asm/zimage.h
index 966d722..9ad74dc 100644
--- a/arch/x86/include/asm/zimage.h
+++ b/arch/x86/include/asm/zimage.h
@@ -89,4 +89,14 @@
 int zboot_start(ulong addr, ulong size, ulong initrd, ulong initrd_size,
 		ulong base, char *cmdline);
 
+/*
+ * zimage_get_kernel_version() - Get the version string from a kernel
+ *
+ * @params: boot_params pointer
+ * @kernel_base: base address of kernel
+ * Return: Kernel version as a NUL-terminated string
+ */
+const char *zimage_get_kernel_version(struct boot_params *params,
+				      void *kernel_base);
+
 #endif

arch/x86/lib/zimage.c

diff --git a/arch/x86/lib/zimage.c b/arch/x86/lib/zimage.c
index 540d4d8..062e3d3 100644
--- a/arch/x86/lib/zimage.c
+++ b/arch/x86/lib/zimage.c
@@ -181,7 +181,7 @@
 	return 0;
 }
 
-static const char *get_kernel_version(struct boot_params *params,
+const char *zimage_get_kernel_version(struct boot_params *params,
 				      void *kernel_base)
 {
 	struct setup_header *hdr = &params->hdr;
@@ -189,10 +189,14 @@
 	const char *s, *end;
 
 	bootproto = get_boot_protocol(hdr, false);
+	log_debug("bootproto %x, hdr->setup_sects %x\n", bootproto,
+		  hdr->setup_sects);
 	if (bootproto < 0x0200 || hdr->setup_sects < 15)
 		return NULL;
 
 	/* sanity-check the kernel version in case it is missing */
+	log_debug("hdr->kernel_version %x, str at %p\n", hdr->kernel_version,
+		  kernel_base + hdr->kernel_version + 0x200);
 	for (s = kernel_base + hdr->kernel_version + 0x200, end = s + 0x100; *s;
 	     s++) {
 		if (!isprint(*s))
@@ -239,7 +243,7 @@
 	log_debug("Using boot protocol version %x.%02x\n",
 		  (bootproto & 0xff00) >> 8, bootproto & 0xff);
 
-	version = get_kernel_version(params, image);
+	version = zimage_get_kernel_version(params, image);
 	if (version)
 		printf("Linux kernel version %s\n", version);
 	else
@@ -728,7 +732,8 @@
 	print_num("Real mode switch", hdr->realmode_swtch);
 	print_num("Start sys seg", hdr->start_sys_seg);
 	print_num("Kernel version", hdr->kernel_version);
-	version = get_kernel_version(base_ptr, (void *)state.bzimage_addr);
+	version = zimage_get_kernel_version(base_ptr,
+					    (void *)state.bzimage_addr);
 	if (version)
 		printf("   @%p: %s\n", version, version);
 	print_num("Type of loader", hdr->type_of_loader);