This command for x86_64 and arm64 shows current paging table on platforms
in question.
Signed-off-by: Vladimir Serbinenko <phco...@gmail.com>
---
grub-core/Makefile.core.def | 8 ++
grub-core/commands/arm64/lspaging.c | 138 +++++++++++++++++++++++++++
grub-core/commands/x86_64/lspaging.c | 115 ++++++++++++++++++++++
3 files changed, 261 insertions(+)
create mode 100644 grub-core/commands/arm64/lspaging.c
create mode 100644 grub-core/commands/x86_64/lspaging.c
diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index f70e02e69..7f8cb3f7d 100644
--- a/grub-core/Makefile.core.def
+++ b/grub-core/Makefile.core.def
@@ -814,6 +814,14 @@ module = {
enable = efi;
};
+module = {
+ name = lspaging;
+ x86_64_efi = commands/x86_64/lspaging.c;
+ arm64_efi = commands/arm64/lspaging.c;
+ enable = arm64_efi;
+ enable = x86_64_efi;
+};
+
module = {
name = lsefimmap;
diff --git a/grub-core/commands/arm64/lspaging.c
b/grub-core/commands/arm64/lspaging.c
new file mode 100644
index 000000000..3d18a09c3
--- /dev/null
+++ b/grub-core/commands/arm64/lspaging.c
@@ -0,0 +1,138 @@
+/* lspaging.c - Display paging table. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2025 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <grub/types.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/normal.h>
+#include <grub/charset.h>
+#include <grub/efi/api.h>
+#include <grub/efi/efi.h>
+#include <grub/dl.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+typedef enum {UNMAPPED, NONIDENTITY, IDENTITY} mapping_type_t;
+
+static const char *mapping_names[] = {
+ "unmapped",
+ "non-identity",
+ "identity",
+};
+
+static bool
+process_level(grub_uint64_t *start_address, mapping_type_t *start_type,
+ grub_uint64_t *next_address, grub_uint64_t *lx, grub_uint64_t
cur_address, int offset)
+{
+ mapping_type_t cur_type;
+ grub_uint64_t entry = ((grub_uint64_t *)*lx)[(cur_address >> offset) &
0x1ff];
+ switch (entry & 3)
+ {
+ case 0:
+ case 2:
+ cur_type = UNMAPPED;
+ break;
+ case 3: /* Table entry */
+ if (offset != 12)
+ {
+ *lx = (entry & 0xfffffffff000);
+ return false;
+ }
+ /* Fallthrough */
+ case 1:
+ cur_type = ((entry & 0xfffffffff000) == (cur_address & 0xfffffffff000))
? IDENTITY : NONIDENTITY;
+ break;
+ }
+
+ *next_address = ((cur_address >> offset) + 1) << offset;
+
+ if (*start_type != cur_type)
+ {
+ if (cur_address != 0)
+ grub_printf("%08lx-%08lx: %s\n", *start_address, cur_address,
mapping_names[*start_type]);
+ *start_type = cur_type;
+ *start_address = cur_address;
+ }
+
+ return true;
+}
+
+static grub_err_t
+grub_cmd_lspaging (struct grub_command *cmd __attribute__ ((unused)),
+ int argc __attribute__ ((unused)),
+ char **args __attribute__ ((unused)))
+{
+ grub_uint64_t tcr_el1, ttbr0_el1;
+ grub_uint64_t id_aa64mmfr3_el1;
+ asm volatile ("mrs %0, id_aa64mmfr3_el1": "=r"(id_aa64mmfr3_el1));
+
+ if (id_aa64mmfr3_el1 & 0xf)
+ {
+ grub_uint64_t tcr2_el1;
+
+ asm volatile ("mrs %0, s3_0_c2_c0_3": "=r"(tcr2_el1));
+ if ((tcr2_el1 >> 5) & 1)
+ return grub_error(GRUB_ERR_NOT_IMPLEMENTED_YET, "Parsing D128 tables
isn't supported yet");
+ }
+ asm volatile ("mrs %0, tcr_el1": "=r"(tcr_el1));
+
+ if ((tcr_el1 >> 14) & 3)
+ return grub_error(GRUB_ERR_NOT_IMPLEMENTED_YET, "non-4K page tables aren't
supported yet");
+
+ grub_uint64_t t0sz = tcr_el1 & 0x3f;
+
+ if (t0sz >= 25)
+ return grub_error(GRUB_ERR_NOT_IMPLEMENTED_YET, "T0SZ %ld isn't supported
yet", t0sz);
+
+ asm volatile ("mrs %0, ttbr0_el1": "=r"(ttbr0_el1));
+
+ grub_uint64_t baddr = (ttbr0_el1 & 0xfffffffffffell);
+ grub_uint64_t start_address = 0, cur_address = 0, next_address = 0;
+ mapping_type_t start_type = UNMAPPED;
+
+ grub_printf("baddr=%lx\n", baddr);
+
+ for (cur_address = 0; cur_address < 0x7fffffffffff; cur_address =
next_address)
+ {
+ grub_uint64_t lx = baddr;
+ if (process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 39))
+ continue;
+ if (process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 30))
+ continue;
+ if (process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 21))
+ continue;
+ process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 12);
+ }
+
+ grub_printf("%08lx-%08lx: %s\n", start_address, cur_address,
mapping_names[start_type]);
+
+ return GRUB_ERR_NONE;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(lspaging)
+{
+ cmd = grub_register_command ("lspaging", grub_cmd_lspaging, "",
+ "Display paging table.");
+}
+
+GRUB_MOD_FINI(lspaging)
+{
+ grub_unregister_command (cmd);
+}
diff --git a/grub-core/commands/x86_64/lspaging.c
b/grub-core/commands/x86_64/lspaging.c
new file mode 100644
index 000000000..ddd39904f
--- /dev/null
+++ b/grub-core/commands/x86_64/lspaging.c
@@ -0,0 +1,115 @@
+/* lspaging.c - Display paging table. */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2025 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <grub/types.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+#include <grub/normal.h>
+#include <grub/charset.h>
+#include <grub/efi/api.h>
+#include <grub/efi/efi.h>
+#include <grub/dl.h>
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+typedef enum {UNMAPPED, NONIDENTITY, IDENTITY} mapping_type_t;
+
+static const char *mapping_names[] = {
+ "unmapped",
+ "non-identity",
+ "identity",
+};
+
+static bool
+process_level(grub_uint64_t *start_address, mapping_type_t *start_type,
+ grub_uint64_t *next_address, grub_uint64_t *lx, grub_uint64_t
cur_address, int offset)
+{
+ mapping_type_t cur_type;
+ grub_uint64_t entry = ((grub_uint64_t *)*lx)[(cur_address >> offset) &
0x1ff];
+ if ((entry & 1) && offset != 12 && !(entry & 0x80))
+ {
+ *lx = (entry & 0xfffffffff000);
+ return false;
+ }
+
+ if ((entry & 1) == 0)
+ {
+ cur_type = UNMAPPED;
+ }
+ else
+ {
+ cur_type = ((entry & 0xfffffffff000) == (cur_address & 0xfffffffff000))
? IDENTITY : NONIDENTITY;
+ }
+
+ *next_address = ((cur_address >> offset) + 1) << offset;
+
+ if (*start_type != cur_type)
+ {
+ if (cur_address != 0)
+ grub_printf("%08lx-%08lx: %s\n", *start_address, cur_address,
mapping_names[*start_type]);
+ *start_type = cur_type;
+ *start_address = cur_address;
+ }
+
+ return true;
+}
+
+static grub_err_t
+grub_cmd_lspaging (struct grub_command *cmd __attribute__ ((unused)),
+ int argc __attribute__ ((unused)),
+ char **args __attribute__ ((unused)))
+{
+ grub_uint64_t cr3;
+
+ asm volatile ("movq %%cr3, %0": "=r"(cr3));
+
+ grub_uint64_t baddr = cr3;
+ grub_uint64_t start_address = 0, cur_address = 0, next_address = 0;
+ mapping_type_t start_type = UNMAPPED;
+
+ grub_printf("baddr=%lx\n", baddr);
+
+ for (cur_address = 0; cur_address < 0x7fffffffffff; cur_address =
next_address)
+ {
+ grub_uint64_t lx = baddr;
+ if (process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 39))
+ continue;
+ if (process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 30))
+ continue;
+ if (process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 21))
+ continue;
+ process_level(&start_address, &start_type, &next_address, &lx,
cur_address, 12);
+ }
+
+ grub_printf("%08lx-%08lx: %s\n", start_address, cur_address,
mapping_names[start_type]);
+
+ return GRUB_ERR_NONE;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(lspaging)
+{
+ cmd = grub_register_command ("lspaging", grub_cmd_lspaging, "",
+ "Display paging table.");
+}
+
+GRUB_MOD_FINI(lspaging)
+{
+ grub_unregister_command (cmd);
+}
--
2.49.0
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