[PATCH v2 16/19] x86: zimage: Export the function to obtain the cmdline

[Simon Glass]

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

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

(no changes since v1)

 arch/x86/include/asm/zimage.h | 10 ++++++++++
 arch/x86/lib/zimage.c         | 11 ++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/zimage.h b/arch/x86/include/asm/zimage.h
index 966d7224eb18..9ad74dc0b946 100644
--- a/arch/x86/include/asm/zimage.h
+++ b/arch/x86/include/asm/zimage.h
@@ -89,4 +89,14 @@ void zimage_dump(struct boot_params *base_ptr);
 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
diff --git a/arch/x86/lib/zimage.c b/arch/x86/lib/zimage.c
index 540d4d888bc7..062e3d3e3151 100644
--- a/arch/x86/lib/zimage.c
+++ b/arch/x86/lib/zimage.c
@@ -181,7 +181,7 @@ static int setup_device_tree(struct setup_header *hdr, 
const void *fdt_blob)
        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 @@ static const char *get_kernel_version(struct boot_params 
*params,
        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 @@ struct boot_params *load_zimage(char *image, unsigned long 
kernel_size,
        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 @@ void zimage_dump(struct boot_params *base_ptr)
        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);
-- 
2.41.0.162.gfafddb0af9-goog