[PATCH] cmd: sysboot: dont overwrite bootfile env

[Artem Lapkin]

Problem

PXE cannot boot normally after Sysboot changed the bootfile env (called
from boot_extlinux) from the default "boot.scr.uimg" to
"/boot/extlinux/extlinux.conf".

In addition, an unbootable extlinux configuration will also make the PXE
boot unbootable, because it will use the incorrect path "/boot/extlinux/"
from the bootfile env.

Solution

sysboot must care about bootfile and restore default value after usage.

Come from:
https://patchwork.ozlabs.org/project/uboot/patch/20211012085544.3206394-1-...@khadas.com/

Signed-off-by: Artem Lapkin <a...@khadas.com>
---
 cmd/sysboot.c | 30 ++++++++++++++++++++----------
 1 file changed, 20 insertions(+), 10 deletions(-)

diff --git a/cmd/sysboot.c b/cmd/sysboot.c
index af6a2f1b7f..99b11cc127 100644
--- a/cmd/sysboot.c
+++ b/cmd/sysboot.c
@@ -2,6 +2,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <malloc.h>
 #include <env.h>
 #include <fs.h>
 #include "pxe_utils.h"
@@ -61,8 +62,9 @@ static int do_sysboot(struct cmd_tbl *cmdtp, int flag, int 
argc,
        unsigned long pxefile_addr_r;
        struct pxe_menu *cfg;
        char *pxefile_addr_str;
-       char *filename;
+       char *filename, *filename_bak;
        int prompt = 0;
+       int ret = 0;
 
        is_pxe = false;
 
@@ -83,9 +85,10 @@ static int do_sysboot(struct cmd_tbl *cmdtp, int flag, int 
argc,
                pxefile_addr_str = argv[4];
        }
 
-       if (argc < 6) {
-               filename = env_get("bootfile");
-       } else {
+       filename = env_get("bootfile");
+       if (argc > 5) {
+               filename_bak = malloc(strlen(filename) + 1);
+               strcpy(filename_bak, filename);
                filename = argv[5];
                env_set("bootfile", filename);
        }
@@ -98,26 +101,26 @@ static int do_sysboot(struct cmd_tbl *cmdtp, int flag, int 
argc,
                do_getfile = do_get_any;
        } else {
                printf("Invalid filesystem: %s\n", argv[3]);
-               return 1;
+               goto err;
        }
        fs_argv[1] = argv[1];
        fs_argv[2] = argv[2];
 
        if (strict_strtoul(pxefile_addr_str, 16, &pxefile_addr_r) < 0) {
                printf("Invalid pxefile address: %s\n", pxefile_addr_str);
-               return 1;
+               goto err;
        }
 
        if (get_pxe_file(cmdtp, filename, pxefile_addr_r) < 0) {
                printf("Error reading config file\n");
-               return 1;
+               goto err;
        }
 
        cfg = parse_pxefile(cmdtp, pxefile_addr_r);
 
        if (!cfg) {
                printf("Error parsing config file\n");
-               return 1;
+               goto err;
        }
 
        if (prompt)
@@ -126,8 +129,15 @@ static int do_sysboot(struct cmd_tbl *cmdtp, int flag, int 
argc,
        handle_pxe_menu(cmdtp, cfg);
 
        destroy_pxe_menu(cfg);
-
-       return 0;
+       goto ret;
+ err:
+       ret = 1;
+ ret:
+       if (filename_bak) {
+               env_set("bootfile", filename_bak);
+               free(filename_bak);
+       }
+       return ret;
 }
 
 U_BOOT_CMD(sysboot, 7, 1, do_sysboot,
-- 
2.25.1