From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Peter Jones <pjones@redhat.com>
Date: Mon, 8 Jul 2019 12:32:37 +0200
Subject: [PATCH] Handle multi-arch (64-on-32) boot in linuxefi loader.
Allow booting 64-bit kernels on 32-bit EFI on x86.
Signed-off-by: Peter Jones <pjones@redhat.com>
---
grub-core/loader/efi/linux.c | 9 +++-
grub-core/loader/i386/efi/linux.c | 110 ++++++++++++++++++++++++++------------
include/grub/i386/linux.h | 7 ++-
3 files changed, 89 insertions(+), 37 deletions(-)
diff --git a/grub-core/loader/efi/linux.c b/grub-core/loader/efi/linux.c
index c8ecce6dfd0..0622dfa48d4 100644
--- a/grub-core/loader/efi/linux.c
+++ b/grub-core/loader/efi/linux.c
@@ -69,12 +69,17 @@ grub_linuxefi_secure_validate (void *data, grub_uint32_t size)
typedef void (*handover_func) (void *, grub_efi_system_table_t *, void *);
grub_err_t
-grub_efi_linux_boot (void *kernel_addr, grub_off_t offset,
+grub_efi_linux_boot (void *kernel_addr, grub_off_t handover_offset,
void *kernel_params)
{
handover_func hf;
+ int offset = 0;
- hf = (handover_func)((char *)kernel_addr + offset);
+#ifdef __x86_64__
+ offset = 512;
+#endif
+
+ hf = (handover_func)((char *)kernel_addr + handover_offset + offset);
hf (grub_efi_image_handle, grub_efi_system_table, kernel_params);
return GRUB_ERR_BUG;
diff --git a/grub-core/loader/i386/efi/linux.c b/grub-core/loader/i386/efi/linux.c
index 6b24cbb9483..3017d0f3e52 100644
--- a/grub-core/loader/i386/efi/linux.c
+++ b/grub-core/loader/i386/efi/linux.c
@@ -44,14 +44,10 @@ static char *linux_cmdline;
static grub_err_t
grub_linuxefi_boot (void)
{
- int offset = 0;
-
-#ifdef __x86_64__
- offset = 512;
-#endif
asm volatile ("cli");
- return grub_efi_linux_boot ((char *)kernel_mem, handover_offset + offset,
+ return grub_efi_linux_boot ((char *)kernel_mem,
+ handover_offset,
params);
}
@@ -153,14 +149,20 @@ grub_cmd_initrd (grub_command_t cmd __attribute__ ((unused)),
return grub_errno;
}
+#define MIN(a, b) \
+ ({ typeof (a) _a = (a); \
+ typeof (b) _b = (b); \
+ _a < _b ? _a : _b; })
+
static grub_err_t
grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
int argc, char *argv[])
{
grub_file_t file = 0;
- struct linux_i386_kernel_header lh;
- grub_ssize_t len, start, filelen;
+ struct linux_i386_kernel_header *lh = NULL;
+ grub_ssize_t start, filelen;
void *kernel = NULL;
+ int setup_header_end_offset;
int rc;
grub_dl_ref (my_mod);
@@ -200,48 +202,79 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
goto fail;
}
- params = grub_efi_allocate_pages_max (0x3fffffff, BYTES_TO_PAGES(16384));
-
+ params = grub_efi_allocate_pages_max (0x3fffffff,
+ BYTES_TO_PAGES(sizeof(*params)));
if (! params)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, "cannot allocate kernel parameters");
goto fail;
}
- grub_dprintf ("linux", "params = %lx\n", (unsigned long) params);
+ grub_dprintf ("linux", "params = %p\n", params);
- grub_memset (params, 0, 16384);
+ grub_memset (params, 0, sizeof(*params));
- grub_memcpy (&lh, kernel, sizeof (lh));
-
- if (lh.boot_flag != grub_cpu_to_le16 (0xaa55))
+ setup_header_end_offset = *((grub_uint8_t *)kernel + 0x201);
+ grub_dprintf ("linux", "copying %lu bytes from %p to %p\n",
+ MIN((grub_size_t)0x202+setup_header_end_offset,
+ sizeof (*params)) - 0x1f1,
+ (grub_uint8_t *)kernel + 0x1f1,
+ (grub_uint8_t *)params + 0x1f1);
+ grub_memcpy ((grub_uint8_t *)params + 0x1f1,
+ (grub_uint8_t *)kernel + 0x1f1,
+ MIN((grub_size_t)0x202+setup_header_end_offset,sizeof (*params)) - 0x1f1);
+ lh = (struct linux_i386_kernel_header *)params;
+ grub_dprintf ("linux", "lh is at %p\n", lh);
+ grub_dprintf ("linux", "checking lh->boot_flag\n");
+ if (lh->boot_flag != grub_cpu_to_le16 (0xaa55))
{
grub_error (GRUB_ERR_BAD_OS, N_("invalid magic number"));
goto fail;
}
- if (lh.setup_sects > GRUB_LINUX_MAX_SETUP_SECTS)
+ grub_dprintf ("linux", "checking lh->setup_sects\n");
+ if (lh->setup_sects > GRUB_LINUX_MAX_SETUP_SECTS)
{
grub_error (GRUB_ERR_BAD_OS, N_("too many setup sectors"));
goto fail;
}
- if (lh.version < grub_cpu_to_le16 (0x020b))
+ grub_dprintf ("linux", "checking lh->version\n");
+ if (lh->version < grub_cpu_to_le16 (0x020b))
{
grub_error (GRUB_ERR_BAD_OS, N_("kernel too old"));
goto fail;
}
- if (!lh.handover_offset)
+ grub_dprintf ("linux", "checking lh->handover_offset\n");
+ if (!lh->handover_offset)
{
grub_error (GRUB_ERR_BAD_OS, N_("kernel doesn't support EFI handover"));
goto fail;
}
+#if defined(__x86_64__) || defined(__aarch64__)
+ grub_dprintf ("linux", "checking lh->xloadflags\n");
+ if (!(lh->xloadflags & LINUX_XLF_KERNEL_64))
+ {
+ grub_error (GRUB_ERR_BAD_OS, N_("kernel doesn't support 64-bit CPUs"));
+ goto fail;
+ }
+#endif
+
+#if defined(__i386__)
+ if ((lh->xloadflags & LINUX_XLF_KERNEL_64) &&
+ !(lh->xloadflags & LINUX_XLF_EFI_HANDOVER_32))
+ {
+ grub_error (GRUB_ERR_BAD_OS,
+ N_("kernel doesn't support 32-bit handover"));
+ goto fail;
+ }
+#endif
+
grub_dprintf ("linux", "setting up cmdline\n");
linux_cmdline = grub_efi_allocate_pages_max(0x3fffffff,
- BYTES_TO_PAGES(lh.cmdline_size + 1));
-
+ BYTES_TO_PAGES(lh->cmdline_size + 1));
if (!linux_cmdline)
{
grub_error (GRUB_ERR_OUT_OF_MEMORY, N_("can't allocate cmdline"));
@@ -254,22 +287,24 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
grub_memcpy (linux_cmdline, LINUX_IMAGE, sizeof (LINUX_IMAGE));
grub_create_loader_cmdline (argc, argv,
linux_cmdline + sizeof (LINUX_IMAGE) - 1,
- lh.cmdline_size - (sizeof (LINUX_IMAGE) - 1),
+ lh->cmdline_size - (sizeof (LINUX_IMAGE) - 1),
GRUB_VERIFY_KERNEL_CMDLINE);
- lh.cmd_line_ptr = (grub_uint32_t)(grub_addr_t)linux_cmdline;
+ grub_dprintf ("linux", "cmdline:%s\n", linux_cmdline);
+ grub_dprintf ("linux", "setting lh->cmd_line_ptr\n");
+ lh->cmd_line_ptr = (grub_uint32_t)(grub_addr_t)linux_cmdline;
- handover_offset = lh.handover_offset;
+ grub_dprintf ("linux", "computing handover offset\n");
+ handover_offset = lh->handover_offset;
- start = (lh.setup_sects + 1) * 512;
- len = grub_file_size(file) - start;
+ start = (lh->setup_sects + 1) * 512;
- kernel_mem = grub_efi_allocate_pages_max(lh.pref_address,
- BYTES_TO_PAGES(lh.init_size));
+ kernel_mem = grub_efi_allocate_pages_max(lh->pref_address,
+ BYTES_TO_PAGES(lh->init_size));
if (!kernel_mem)
kernel_mem = grub_efi_allocate_pages_max(0x3fffffff,
- BYTES_TO_PAGES(lh.init_size));
+ BYTES_TO_PAGES(lh->init_size));
if (!kernel_mem)
{
@@ -277,14 +312,21 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
goto fail;
}
- grub_memcpy (kernel_mem, (char *)kernel + start, len);
+ grub_dprintf ("linux", "kernel_mem = %lx\n", (unsigned long) kernel_mem);
+
grub_loader_set (grub_linuxefi_boot, grub_linuxefi_unload, 0);
loaded=1;
+ grub_dprintf ("linux", "setting lh->code32_start to %p\n", kernel_mem);
+ lh->code32_start = (grub_uint32_t)(grub_addr_t) kernel_mem;
- lh.code32_start = (grub_uint32_t)(grub_uint64_t) kernel_mem;
- grub_memcpy (params, &lh, 2 * 512);
+ grub_memcpy (kernel_mem, (char *)kernel + start, filelen - start);
- params->type_of_loader = 0x21;
+ grub_dprintf ("linux", "setting lh->type_of_loader\n");
+ lh->type_of_loader = 0x6;
+
+ grub_dprintf ("linux", "setting lh->ext_loader_{type,ver}\n");
+ params->ext_loader_type = 0;
+ params->ext_loader_ver = 2;
grub_dprintf("linux", "kernel_mem: %p handover_offset: %08x\n",
kernel_mem, handover_offset);
@@ -301,10 +343,10 @@ grub_cmd_linux (grub_command_t cmd __attribute__ ((unused)),
loaded = 0;
}
- if (linux_cmdline && !loaded)
+ if (linux_cmdline && lh && !loaded)
grub_efi_free_pages ((grub_efi_physical_address_t)(grub_addr_t)
linux_cmdline,
- BYTES_TO_PAGES(lh.cmdline_size + 1));
+ BYTES_TO_PAGES(lh->cmdline_size + 1));
if (kernel_mem && !loaded)
grub_efi_free_pages ((grub_efi_physical_address_t)(grub_addr_t)kernel_mem,
diff --git a/include/grub/i386/linux.h b/include/grub/i386/linux.h
index eddf9251d9a..25ef52c04eb 100644
--- a/include/grub/i386/linux.h
+++ b/include/grub/i386/linux.h
@@ -138,7 +138,12 @@ struct linux_i386_kernel_header
grub_uint32_t kernel_alignment;
grub_uint8_t relocatable;
grub_uint8_t min_alignment;
- grub_uint8_t pad[2];
+#define LINUX_XLF_KERNEL_64 (1<<0)
+#define LINUX_XLF_CAN_BE_LOADED_ABOVE_4G (1<<1)
+#define LINUX_XLF_EFI_HANDOVER_32 (1<<2)
+#define LINUX_XLF_EFI_HANDOVER_64 (1<<3)
+#define LINUX_XLF_EFI_KEXEC (1<<4)
+ grub_uint16_t xloadflags;
grub_uint32_t cmdline_size;
grub_uint32_t hardware_subarch;
grub_uint64_t hardware_subarch_data;