cpu/x86/64bit: Generate static page tables from an assembly file
This removes the need for a tool to generate simple identity pages. Future patches will link this page table directly into the stages on some platforms so having an assembly file makes a lot of sense. This also optimizes the size of the page of each 4K page by placing the PDPE_table below the PDE. Change-Id: Ia1e31b701a2584268c85d327bf139953213899e3 Signed-off-by: Arthur Heymans <arthur@aheymans.xyz> Reviewed-on: https://review.coreboot.org/c/coreboot/+/63725 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Raul Rangel <rrangel@chromium.org>
This commit is contained in:
Arthur Heymans
Felix Held
parent
34f5cd9cb2
commit
597b9e9d71
|
|
@ -26,9 +26,7 @@ In order to add support for x86_64 the following assumptions were made:
|
|||
* A stage can install new page tables in RAM
|
||||
|
||||
## Page tables
|
||||
Page tables are generated by a tool in `util/pgtblgen/pgtblgen`. It writes
|
||||
the page tables to a file which is then included into the CBFS as file called
|
||||
`pagetables`.
|
||||
A `pagetables` cbfs file is generated based on an assembly file.
|
||||
|
||||
To generate the static page tables it must know the physical address where to
|
||||
place the file.
|
||||
|
|
|
|||
|
|
@ -5,3 +5,15 @@ endif
|
|||
romstage-y += mode_switch.S
|
||||
postcar-y += mode_switch.S
|
||||
ramstage-y += mode_switch.S
|
||||
|
||||
# Add --defsym=_start=0 to suppress a linker warning.
|
||||
$(objcbfs)/pt: $(dir)/pt.S
|
||||
$(CC_bootblock) $(CFLAGS_bootblock) $(CPPFLAGS_bootblock) -o $@.tmp $< -Wl,--section-start=.rodata=$(CONFIG_ARCH_X86_64_PGTBL_LOC),--defsym=_start=0
|
||||
$(OBJCOPY_ramstage) -Obinary -j .rodata $@.tmp $@
|
||||
rm $@.tmp
|
||||
|
||||
cbfs-files-y += pagetables
|
||||
pagetables-file := $(objcbfs)/pt
|
||||
pagetables-type := raw
|
||||
pagetables-compression := none
|
||||
pagetables-COREBOOT-position := $(CONFIG_ARCH_X86_64_PGTBL_LOC)
|
||||
|
|
|
|||
|
|
@ -0,0 +1,35 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0-only */
|
||||
|
||||
/*
|
||||
* For reference see "AMD64 Architecture Programmer's Manual Volume 2",
|
||||
* Document 24593-Rev. 3.31-July 2019 Chapter 5.3.4
|
||||
*
|
||||
* Page table attributes: WB, User+Supervisor, Present, Writeable, Accessed, Dirty
|
||||
*/
|
||||
|
||||
.section .rodata
|
||||
#define _PRES (1ULL << 0)
|
||||
#define _RW (1ULL << 1)
|
||||
#define _US (1ULL << 2)
|
||||
#define _A (1ULL << 5)
|
||||
#define _D (1ULL << 6)
|
||||
#define _PS (1ULL << 7)
|
||||
#define _GEN_DIR(a) (_PRES + _RW + _US + _A + (a))
|
||||
#define _GEN_PAGE(a) (_PRES + _RW + _US + _PS + _A + _D + (a))
|
||||
|
||||
.global PM4LE
|
||||
.align 32
|
||||
PM4LE:
|
||||
.quad _GEN_DIR(PDPE_table)
|
||||
|
||||
.align 4096
|
||||
PDE_tables: /* identity map 2MiB pages */
|
||||
.rept 2048
|
||||
.quad _GEN_PAGE(0x200000 * ((. - PDE_tables) >> 3))
|
||||
.endr
|
||||
|
||||
.align 4096
|
||||
PDPE_table: /* Point to PDE */
|
||||
.rept 4
|
||||
.quad _GEN_DIR(PDE_tables + 4096 * ((. - PDPE_table) >> 3))
|
||||
.endr
|
||||
|
|
@ -1,19 +0,0 @@
|
|||
ifeq ($(CONFIG_ARCH_BOOTBLOCK_X86_64),y)
|
||||
|
||||
PGTBLGEN:= $(obj)/pgtblgen
|
||||
|
||||
cbfs-files-y += pagetables
|
||||
pagetables-file := $(obj)/mainboard/$(MAINBOARDDIR)/pagetables
|
||||
pagetables-type := raw
|
||||
pagetables-compression := none
|
||||
pagetables-COREBOOT-position := $(CONFIG_ARCH_X86_64_PGTBL_LOC)
|
||||
|
||||
$(obj)/mainboard/$(MAINBOARDDIR)/pagetables: $(PGTBLGEN) $(obj)/config.h
|
||||
printf " TOOL Creating page tables\n"
|
||||
$(PGTBLGEN) -b $(CONFIG_ARCH_X86_64_PGTBL_LOC) -a x86_64 -o $@
|
||||
|
||||
$(PGTBLGEN): util/pgtblgen/pgtblgen.c
|
||||
printf " MAKE Creating PGTBLGEN tool\n"
|
||||
$(HOSTCC) -std=c99 $< -I$(obj) -o $@
|
||||
|
||||
endif
|
||||
|
|
@ -1 +0,0 @@
|
|||
Generates page tables based on fixed physical address. `C`
|
||||
|
|
@ -1,158 +0,0 @@
|
|||
/* SPDX-License-Identifier: GPL-2.0-only */
|
||||
|
||||
#include <stdio.h>
|
||||
#include <stdlib.h>
|
||||
#include <unistd.h>
|
||||
#include <string.h>
|
||||
#include <sys/types.h>
|
||||
#include <sys/stat.h>
|
||||
#include <fcntl.h>
|
||||
#include <errno.h>
|
||||
#include <inttypes.h>
|
||||
#include <getopt.h>
|
||||
|
||||
static void usage(char *argv[])
|
||||
{
|
||||
printf("usage: %s -b <addr> -a <arch> -o <file>\n", argv[0]);
|
||||
printf(" -a\t architecture. Supported: x86_64\n");
|
||||
printf(" -b\t base address\n");
|
||||
printf(" -o\t the file to write to\n");
|
||||
printf(" -h\t show this help text\n");
|
||||
}
|
||||
|
||||
/*
|
||||
* For reference see "AMD64 ArchitectureProgrammer's Manual Volume 2",
|
||||
* Document 24593-Rev. 3.31-July 2019 Chapter 5.3.4
|
||||
*
|
||||
* Page table attributes: WB, User+Supervisor, Present, Writeable, Accessed, Dirty
|
||||
*/
|
||||
#define _PRES (1ULL << 0)
|
||||
#define _RW (1ULL << 1)
|
||||
#define _US (1ULL << 2)
|
||||
#define _A (1ULL << 5)
|
||||
#define _D (1ULL << 6)
|
||||
#define _PS (1ULL << 7)
|
||||
#define _GEN_DIR(a) (_PRES | _RW | _US | _A | (a))
|
||||
#define _GEN_PAGE(a) (_PRES | _RW | _US | _PS | _A | _D | (a))
|
||||
|
||||
/*
|
||||
* Generate x86_64 page tables.
|
||||
* The page tables needs to be placed at @base_address, and identity map
|
||||
* the first @size_gib GiB of physical memory.
|
||||
*/
|
||||
static int gen_pgtbl_x86_64(const uint64_t base_address,
|
||||
const size_t size_gib,
|
||||
void **out_buf,
|
||||
size_t *out_size)
|
||||
{
|
||||
uint64_t *entry;
|
||||
|
||||
if (!out_size || !out_buf)
|
||||
return 1;
|
||||
|
||||
*out_size = (size_gib + 2) * 4096;
|
||||
*out_buf = malloc(*out_size);
|
||||
if (!*out_buf)
|
||||
return 1;
|
||||
|
||||
memset(*out_buf, 0, *out_size);
|
||||
entry = (uint64_t *)*out_buf;
|
||||
|
||||
/* Generate one PM4LE entry - point to PDPE */
|
||||
entry[0] = _GEN_DIR(base_address + 4096);
|
||||
entry += 512;
|
||||
|
||||
/* PDPE table - point to PDE */
|
||||
for (size_t i = 0; i < size_gib; i++)
|
||||
entry[i] = _GEN_DIR(base_address + 4096 * (i + 2));
|
||||
entry += 512;
|
||||
|
||||
/* PDE tables - identity map 2MiB pages */
|
||||
for (size_t g = 0; g < size_gib; g++) {
|
||||
for (size_t i = 0; i < 512; i++) {
|
||||
uint64_t addr = ((1ULL << (12 + 9)) * i) | ((1ULL << (12 + 9 + 9)) * g);
|
||||
entry[i] = _GEN_PAGE(addr);
|
||||
}
|
||||
entry += 512;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int main(int argc, char *argv[])
|
||||
{
|
||||
int ret = 1;
|
||||
uint64_t base_address = 0;
|
||||
char *filename = NULL;
|
||||
char *arch = NULL;
|
||||
void *buf = NULL;
|
||||
size_t buf_size = 0;
|
||||
int c;
|
||||
|
||||
while ((c = getopt(argc, argv, "ho:a:b:")) != -1)
|
||||
switch (c) {
|
||||
case '?': /* falltrough */
|
||||
case 'h':
|
||||
usage(argv);
|
||||
return 0;
|
||||
case 'o':
|
||||
filename = optarg;
|
||||
break;
|
||||
case 'a':
|
||||
arch = optarg;
|
||||
break;
|
||||
case 'b':
|
||||
base_address = strtoull(optarg, NULL, 0);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
if (!filename) {
|
||||
fprintf(stderr, "E: Missing filename.\n");
|
||||
goto done;
|
||||
}
|
||||
if (!arch) {
|
||||
fprintf(stderr, "E: Missing architecture.\n");
|
||||
goto done;
|
||||
} else if (strcmp(arch, "x86_64") != 0) {
|
||||
fprintf(stderr, "E: Unsupported architecture.\n");
|
||||
goto done;
|
||||
}
|
||||
if (base_address & 4095) {
|
||||
fprintf(stderr, "E: Base address not 4 KiB aligned\n");
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* FIXME: Identity map 4GiB for now, increase if necessary */
|
||||
if (strcmp(arch, "x86_64") == 0)
|
||||
ret = gen_pgtbl_x86_64(base_address, 4, &buf, &buf_size);
|
||||
|
||||
if (ret) {
|
||||
fprintf(stderr, "Failed to generate page tables\n");
|
||||
goto done;
|
||||
}
|
||||
|
||||
// write the table
|
||||
FILE *fd = fopen(filename, "wb");
|
||||
if (!fd) {
|
||||
fprintf(stderr, "%s open failed: %s\n", filename, strerror(errno));
|
||||
goto done;
|
||||
}
|
||||
|
||||
if (fwrite(buf, 1, buf_size, fd) != buf_size) {
|
||||
fprintf(stderr, "%s write failed: %s\n", filename, strerror(errno));
|
||||
fclose(fd);
|
||||
goto done;
|
||||
}
|
||||
|
||||
if (fclose(fd)) {
|
||||
fprintf(stderr, "%s close failed: %s\n", filename, strerror(errno));
|
||||
goto done;
|
||||
}
|
||||
|
||||
ret = 0;
|
||||
done:
|
||||
free(buf);
|
||||
return ret;
|
||||
}
|
||||
Loading…
Reference in New Issue