[meta-intel] [PATCH RFC] systemd-boot_%.bbappend: Add stub command line modifications patch
California Sullivan
california.l.sullivan at intel.com
Wed Jun 14 18:47:41 PDT 2017
Allows you to modify the command line when called from EFI shell
instead of the entire command line getting replaced.
Signed-off-by: California Sullivan <california.l.sullivan at intel.com>
---
I liked this idea so I gave it a shot. Let me know what you think.
Commit message is a WIP. Its getting late but I'd like some feedback.
...ub-allow-smarter-command-line-modificatio.patch | 132 +++++++++++++++++++++
.../systemd-boot/systemd-boot_%.bbappend | 1 +
2 files changed, 133 insertions(+)
create mode 100644 common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch
diff --git a/common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch b/common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch
new file mode 100644
index 0000000..9cc92c9
--- /dev/null
+++ b/common/recipes-bsp/systemd-boot/systemd-boot/0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch
@@ -0,0 +1,132 @@
+From 47a4ce351911625f227b8b29d9c307d5c32fd32f Mon Sep 17 00:00:00 2001
+From: California Sullivan <california.l.sullivan at intel.com>
+Date: Wed, 14 Jun 2017 17:33:30 -0700
+Subject: [PATCH] boot: efi: stub: allow smarter command line modifications
+
+Currently, the command line is replaced with anything that ends up in
+LoadOptions. LoadOptions gets populated by the firmware, and EFI shell
+command line information when running a binary. This includes the name
+of the binary itself, so it will usually break booting from the EFI
+shell.
+
+Instead, have LoadOptions modify the command line in the following way:
+
+bootx64 root=/dev/sda -> prepend the command line (default)
+bootx64 ^console=/dev/tty0 -> prepend the command line (explicit)
+bootx64 $console=/dev/tty0 -> append the command line
+bootx64 !console=/dev/tty0 root=/dev/sda -> replace the command line
+
+The '^', '$' and '!' characters act as sentinel values, telling the EFI
+stub how to handle LoadOptions values, as well as indicating where
+command line modifications in LoadOptions should begin.
+
+Note that with the default case, bootx64 will end up in the kernel
+command line, as we use the sentinel values to decide where to begin the
+command line modifications.
+
+Signed-off-by: California Sullivan <california.l.sullivan at intel.com>
+---
+ src/boot/efi/stub.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++---
+ 1 file changed, 78 insertions(+), 4 deletions(-)
+
+diff --git a/src/boot/efi/stub.c b/src/boot/efi/stub.c
+index 74e95fd..a4b34a2 100644
+--- a/src/boot/efi/stub.c
++++ b/src/boot/efi/stub.c
+@@ -93,15 +93,89 @@ EFI_STATUS efi_main(EFI_HANDLE image, EFI_SYSTEM_TABLE *sys_table) {
+ /* if we are not in secure boot mode, accept a custom command line and replace the built-in one */
+ if (!secure && loaded_image->LoadOptionsSize > 0 && *(CHAR16 *)loaded_image->LoadOptions != 0) {
+ CHAR16 *options;
++ CHAR8 mode;
+ CHAR8 *line;
++ UINTN options_len;
++ UINTN total_len;
+ UINTN i;
++ UINTN j;
++ UINTN k;
+
+ options = (CHAR16 *)loaded_image->LoadOptions;
+- cmdline_len = (loaded_image->LoadOptionsSize / sizeof(CHAR16)) * sizeof(CHAR8);
+- line = AllocatePool(cmdline_len);
+- for (i = 0; i < cmdline_len; i++)
+- line[i] = options[i];
++ options_len = (loaded_image->LoadOptionsSize / sizeof(CHAR16)) * sizeof(CHAR8);
++
++ mode = '?';
++ /* walk through options to find sentinel values indicating alternative modes
++ * also use this index to begin the command line changes
++ * this lets us avoid adding the binary name to the command line */
++ for(i = 0; i < options_len; i++) {
++ if (options[i] == '$' ||
++ options[i] == '!' ||
++ options[i] == '^') {
++ mode = options[i];
++ break;
++ }
++ }
++
++ switch(mode) {
++
++ /* append to the cmdline */
++ case '$':
++ total_len = cmdline_len + options_len - i + 1;
++ i++;
++ line = AllocatePool(total_len);
++ for (j = 0; j < cmdline_len; j++)
++ line[j] = cmdline[j];
++
++ line[j++] = ' ';
++
++ for (k = 0; i + k < options_len && j + k < total_len; k++)
++ line[j + k] = options[i + k];
++
++ break;
++
++ /* replace the cmdline */
++ case '!':
++ total_len = options_len - i;
++ i++;
++ line = AllocatePool(total_len);
++ for (j = 0; i + j < options_len; j++)
++ line[j] = options[i + j];
++ break;
++
++ /* prepend to cmdline */
++ case '^':
++ total_len = cmdline_len + options_len - i;
++ i++;
++ line = AllocatePool(total_len);
++
++ /* Ignore null character at last index */
++ for (j = 0; i + j < options_len - 1; j++)
++ line[j] = options[i + j];
++
++ line[j++] = ' ';
++
++ for (k = 0; k < cmdline_len && j + k < total_len; k++)
++ line[j + k] = cmdline[k];
++ break;
++
++ /* prepend anyway, but don't get rid of binary name since we couldn't find a sentinel */
++ default:
++ total_len = cmdline_len + options_len;
++ line = AllocatePool(total_len);
++ /* Ignore null character at last index */
++ for (i = 0; i < options_len - 1; i++)
++ line[i] = options[i];
++
++ line[i++] = ' ';
++
++ for (j = 0; j < cmdline_len && i + j < total_len; j++)
++ line[i + j] = cmdline[j];
++ break;
++ }
++
+ cmdline = line;
++ cmdline_len = total_len;
+
+ #ifdef SD_BOOT_LOG_TPM
+ /* Try to log any options to the TPM, escpecially manually edited options */
+--
+2.5.5
+
diff --git a/common/recipes-bsp/systemd-boot/systemd-boot_%.bbappend b/common/recipes-bsp/systemd-boot/systemd-boot_%.bbappend
index 98eaf45..05bc490 100644
--- a/common/recipes-bsp/systemd-boot/systemd-boot_%.bbappend
+++ b/common/recipes-bsp/systemd-boot/systemd-boot_%.bbappend
@@ -21,6 +21,7 @@ SRC_URI_append_intel-x86-common = " \
file://0004-sd-boot-Support-global-kernel-command-line-fragment-in-EFI-stub.patch \
file://0001-efi-boot.c-workaround-for-Joule-BIOS-hang.patch \
file://0001-sd-boot-stub-check-LoadOptions-contains-data.patch \
+ file://0001-boot-efi-stub-allow-smarter-command-line-modificatio.patch \
"
PACKAGE_ARCH_intel-x86-common = "${INTEL_COMMON_PACKAGE_ARCH}"
--
2.5.5
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