On Sun, Jul 27, 2025 at 01:54:35AM +0000, Alec Brown wrote:
> From: Robbie Harwood <[email protected]>
>
> Irritatingly, BLS defines paths relative to the mountpoint of the
> filesystem which contains its snippets, not / or any other fixed
> location. So grub2-emu needs to know whether /boot is a separate
> filesystem from / and conditionally prepend a path.
>
> Signed-off-by: Robbie Harwood <[email protected]>
> Signed-off-by: Alec Brown <[email protected]>
> ---
> grub-core/Makefile.core.def | 3 ++
> grub-core/commands/blsuki.c | 89 ++++++++++++++++++++++++++++++---
> grub-core/osdep/linux/getroot.c | 8 +++
> grub-core/osdep/unix/getroot.c | 4 +-
> include/grub/emu/misc.h | 2 +-
> 5 files changed, 97 insertions(+), 9 deletions(-)
>
> diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
> index 996a1c2ae..9488654fb 100644
> --- a/grub-core/Makefile.core.def
> +++ b/grub-core/Makefile.core.def
> @@ -367,6 +367,9 @@ kernel = {
> emu = kern/emu/cache_s.S;
> emu = kern/emu/hostdisk.c;
> emu = osdep/unix/hostdisk.c;
> + emu = osdep/relpath.c;
> + emu = osdep/getroot.c;
> + emu = osdep/unix/getroot.c;
> emu = osdep/exec.c;
> extra_dist = osdep/unix/exec.c;
> emu = osdep/devmapper/hostdisk.c;
> diff --git a/grub-core/commands/blsuki.c b/grub-core/commands/blsuki.c
> index c275dbb92..76615e9bc 100644
> --- a/grub-core/commands/blsuki.c
> +++ b/grub-core/commands/blsuki.c
> @@ -32,6 +32,13 @@
> #include <grub/lib/envblk.h>
> #include <filevercmp.h>
>
> +#ifdef GRUB_MACHINE_EMU
> +#include <grub/emu/misc.h>
> +#define GRUB_BOOT_DEVICE "/boot"
> +#else
> +#define GRUB_BOOT_DEVICE ""
> +#endif
> +
> GRUB_MOD_LICENSE ("GPLv3+");
>
> #define GRUB_BLS_CONFIG_PATH "/loader/entries/"
> @@ -75,6 +82,40 @@ static grub_blsuki_entry_t *entries;
>
> #define FOR_BLSUKI_ENTRIES(var) FOR_LIST_ELEMENTS (var, entries)
>
> +#ifdef GRUB_MACHINE_EMU
> +/*
> + * Cache probing in blsuki_update_boot_device().
> + */
> +static int separate_boot = -1;
You can make it a static in the function...
> +#endif
> +
> +/*
> + * BLS appears to make paths relative to the filesystem that snippets are
> + * on, not /. Attempt to cope.
> + */
> +static char *blsuki_update_boot_device (char *tmp)
> +{
> +#ifdef GRUB_MACHINE_EMU
> + char *ret;
> +
> + if (separate_boot != -1)
> + goto probed;
> +
> + separate_boot = 0;
> +
> + ret = grub_make_system_path_relative_to_its_root (GRUB_BOOT_DEVICE);
> +
> + if (ret != NULL && ret[0] == '\0')
> + separate_boot = 1;
> +
> + probed:
> + if (!separate_boot)
> + return tmp;
> +#endif
> +
> + return grub_stpcpy (tmp, GRUB_BOOT_DEVICE);
> +}
[...]
> -static void
> +static grub_err_t
> blsuki_find_entry (struct find_entry_info *info, bool enable_fallback)
> {
> struct read_entry_info read_entry_info;
> + char *default_dir = NULL;
> + char *tmp;
> + grub_size_t default_size;
> grub_fs_t dir_fs = NULL;
> grub_device_t dir_dev = NULL;
> bool fallback = false;
> @@ -837,7 +888,15 @@ blsuki_find_entry (struct find_entry_info *info, bool
> enable_fallback)
> */
> if (entries == NULL && fallback == false && enable_fallback == true)
> {
> - blsuki_set_find_entry_info (info, GRUB_BLS_CONFIG_PATH, NULL);
> + default_size = sizeof (GRUB_BOOT_DEVICE) + sizeof
> (GRUB_BLS_CONFIG_PATH) - 2;
s/2/1/?
> + default_dir = grub_malloc (default_size);
> + if (default_dir == NULL)
> + return grub_errno;
> +
> + tmp = blsuki_update_boot_device (default_dir);
> + tmp = grub_stpcpy (tmp, GRUB_BLS_CONFIG_PATH);
> +
> + blsuki_set_find_entry_info (info, default_dir, NULL);
> grub_dprintf ("blsuki", "Entries weren't found in %s, fallback to
> %s\n",
> read_entry_info.dirname, info->dirname);
> fallback = true;
> @@ -846,6 +905,9 @@ blsuki_find_entry (struct find_entry_info *info, bool
> enable_fallback)
> fallback = false;
> }
> while (fallback == true);
> +
> + grub_free (default_dir);
> + return GRUB_ERR_NONE;
> }
>
> static grub_err_t
> @@ -855,6 +917,9 @@ blsuki_load_entries (char *path, bool enable_fallback)
> static grub_err_t r;
> const char *devid = NULL;
> char *dir = NULL;
> + char *default_dir = NULL;
> + char *tmp;
> + grub_size_t dir_size;
> struct find_entry_info info = {
> .dev = NULL,
> .fs = NULL,
> @@ -896,15 +961,25 @@ blsuki_load_entries (char *path, bool enable_fallback)
> }
>
> if (dir == NULL)
> - dir = (char *) GRUB_BLS_CONFIG_PATH;
> + {
> + dir_size = sizeof (GRUB_BOOT_DEVICE) + sizeof (GRUB_BLS_CONFIG_PATH) -
> 2;
> + default_dir = grub_malloc (dir_size);
> + if (default_dir == NULL)
> + return grub_errno;
> +
> + tmp = blsuki_update_boot_device (default_dir);
> + tmp = grub_stpcpy (tmp, GRUB_BLS_CONFIG_PATH);
> + dir = default_dir;
> + }
>
> r = blsuki_set_find_entry_info (&info, dir, devid);
> if (r == GRUB_ERR_NONE)
> - blsuki_find_entry (&info, enable_fallback);
> + r = blsuki_find_entry (&info, enable_fallback);
>
> if (info.dev != NULL)
> grub_device_close (info.dev);
>
> + grub_free (default_dir);
> return r;
> }
Daniel
_______________________________________________
Grub-devel mailing list
[email protected]
https://lists.gnu.org/mailman/listinfo/grub-devel
