Commit 801820be authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by Ingo Molnar
Browse files

efi/arm/libstub: Make screen_info accessible to the UEFI stub



In order to hand over the framebuffer described by the GOP protocol and
discovered by the UEFI stub, make struct screen_info accessible by the
stub. This involves allocating a loader data buffer and passing it to the
kernel proper via a UEFI Configuration Table, since the UEFI stub executes
in the context of the decompressor, and cannot access the kernel's copy of
struct screen_info directly.

Signed-off-by: default avatarArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: default avatarMatt Fleming <matt@codeblueprint.co.uk>
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1461614832-17633-22-git-send-email-matt@codeblueprint.co.uk


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 57fdb89a
......@@ -64,6 +64,9 @@ void efi_virtmap_unload(void);
#define __efi_call_early(f, ...) f(__VA_ARGS__)
#define efi_is_64bit() (false)
struct screen_info *alloc_screen_info(efi_system_table_t *sys_table_arg);
void free_screen_info(efi_system_table_t *sys_table, struct screen_info *si);
/*
* A reasonable upper bound for the uncompressed kernel size is 32 MBytes,
* so we will reserve that amount of memory. We have no easy way to tell what
......
......@@ -883,7 +883,8 @@ static void __init request_standard_resources(const struct machine_desc *mdesc)
request_resource(&ioport_resource, &lp2);
}
#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE)
#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) || \
defined(CONFIG_EFI)
struct screen_info screen_info = {
.orig_video_lines = 30,
.orig_video_cols = 80,
......
......@@ -11,12 +11,15 @@
*
*/
#define pr_fmt(fmt) "efi: " fmt
#include <linux/efi.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/mm_types.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/screen_info.h>
#include <asm/efi.h>
......@@ -51,6 +54,32 @@ static phys_addr_t efi_to_phys(unsigned long addr)
return addr;
}
static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
static __initdata efi_config_table_type_t arch_tables[] = {
{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table},
{NULL_GUID, NULL, NULL}
};
static void __init init_screen_info(void)
{
struct screen_info *si;
if (screen_info_table != EFI_INVALID_TABLE_ADDR) {
si = early_memremap_ro(screen_info_table, sizeof(*si));
if (!si) {
pr_err("Could not map screen_info config table\n");
return;
}
screen_info = *si;
early_memunmap(si, sizeof(*si));
/* dummycon on ARM needs non-zero values for columns/lines */
screen_info.orig_video_cols = 80;
screen_info.orig_video_lines = 25;
}
}
static int __init uefi_init(void)
{
efi_char16_t *c16;
......@@ -108,7 +137,8 @@ static int __init uefi_init(void)
goto out;
}
retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables,
sizeof(efi_config_table_t), NULL);
sizeof(efi_config_table_t),
arch_tables);
early_memunmap(config_tables, table_size);
out:
......@@ -223,4 +253,6 @@ void __init efi_init(void)
PAGE_ALIGN(params.mmap_size +
(params.mmap & ~PAGE_MASK)));
}
init_screen_info();
}
......@@ -353,8 +353,9 @@ static __init int match_config_table(efi_guid_t *guid,
for (i = 0; efi_guidcmp(table_types[i].guid, NULL_GUID); i++) {
if (!efi_guidcmp(*guid, table_types[i].guid)) {
*(table_types[i].ptr) = table;
pr_cont(" %s=0x%lx ",
table_types[i].name, table);
if (table_types[i].name)
pr_cont(" %s=0x%lx ",
table_types[i].name, table);
return 1;
}
}
......
......@@ -26,6 +26,43 @@ efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
return EFI_SUCCESS;
}
static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID;
struct screen_info *alloc_screen_info(efi_system_table_t *sys_table_arg)
{
struct screen_info *si;
efi_status_t status;
/*
* Unlike on arm64, where we can directly fill out the screen_info
* structure from the stub, we need to allocate a buffer to hold
* its contents while we hand over to the kernel proper from the
* decompressor.
*/
status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
sizeof(*si), (void **)&si);
if (status != EFI_SUCCESS)
return NULL;
status = efi_call_early(install_configuration_table,
&screen_info_guid, si);
if (status == EFI_SUCCESS)
return si;
efi_call_early(free_pool, si);
return NULL;
}
void free_screen_info(efi_system_table_t *sys_table_arg, struct screen_info *si)
{
if (!si)
return;
efi_call_early(install_configuration_table, &screen_info_guid, NULL);
efi_call_early(free_pool, si);
}
efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
unsigned long *image_addr,
unsigned long *image_size,
......
......@@ -286,7 +286,7 @@ typedef struct {
efi_status_t (*locate_handle)(int, efi_guid_t *, void *,
unsigned long *, efi_handle_t *);
void *locate_device_path;
void *install_configuration_table;
efi_status_t (*install_configuration_table)(efi_guid_t *, void *);
void *load_image;
void *start_image;
void *exit;
......@@ -633,6 +633,15 @@ void efi_native_runtime_setup(void);
EFI_GUID(0xd3b36f2c, 0xd551, 0x11d4, \
0x9a, 0x46, 0x00, 0x90, 0x27, 0x3f, 0xc1, 0x4d)
/*
* This GUID is used to pass to the kernel proper the struct screen_info
* structure that was populated by the stub based on the GOP protocol instance
* associated with ConOut
*/
#define LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID \
EFI_GUID(0xe03fc20a, 0x85dc, 0x406e, \
0xb9, 0xe, 0x4a, 0xb5, 0x02, 0x37, 0x1d, 0x95)
typedef struct {
efi_guid_t guid;
u64 table;
......
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment