vboot: prepare for x86 verstage

In order to support x86 verstage proper the work buffer
needs to live in cache-as-ram. However, after cache-as-ram
is torn down one still needs the verification results to
know which slot was selected. Though the platforms with
a dedicated SRAM can just use the work buffer in SRAM, the
x86 cache-as-ram platforms need a place to stash the
results. For that situation cbmem is employed. This works
because when cbmem is initialized cache-as-ram is still
enabled. The VBOOT_DYNAMIC_WORK_BUFFER case assumes
verified boot doesn't start until after cbmem is up. That
doesn't change, but it's a goal to get rid of that option
entirely once all other x86 platforms are moved over to
pre-romstage vboot.

BUG=chrome-os-partner:44827
BRANCH=None
TEST=Built and booted glados with pre-romstage verification
     as well as VBOOT_DYNAMIC_WORK_BUFFER case.

Change-Id: I7eacd0edb2b6ca52b59b74075d17c00b50676d4c
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/11821
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
This commit is contained in:
Aaron Durbin 2015-10-07 16:03:41 -05:00 committed by Aaron Durbin
parent ed253c8fd8
commit b593366e34
5 changed files with 99 additions and 15 deletions

View File

@ -65,6 +65,7 @@
#define CBMEM_ID_TCPA_LOG 0x54435041
#define CBMEM_ID_TIMESTAMP 0x54494d45
#define CBMEM_ID_VBOOT_HANDOFF 0x780074f0
#define CBMEM_ID_VBOOT_SEL_REG 0x780074f1
#define CBMEM_ID_VBOOT_WORKBUF 0x78007343
#define CBMEM_ID_WIFI_CALIBRATION 0x57494649
@ -108,6 +109,7 @@
{ CBMEM_ID_TCPA_LOG, "TCPA LOG " }, \
{ CBMEM_ID_TIMESTAMP, "TIME STAMP " }, \
{ CBMEM_ID_VBOOT_HANDOFF, "VBOOT " }, \
{ CBMEM_ID_VBOOT_SEL_REG, "VBOOT SEL " }, \
{ CBMEM_ID_VBOOT_WORKBUF, "VBOOT WORK " }, \
{ CBMEM_ID_WIFI_CALIBRATION, "WIFI CLBR " },
#endif /* _CBMEM_ID_H_ */

View File

@ -28,6 +28,11 @@
#include "../vboot_handoff.h"
#include "misc.h"
struct selected_region {
uint32_t offset;
uint32_t size;
};
/*
* this is placed at the start of the vboot work buffer. selected_region is used
* for the verstage to return the location of the selected slot. buffer is used
@ -35,8 +40,7 @@
* stage boundaries.
*/
struct vb2_working_data {
uint32_t selected_region_offset;
uint32_t selected_region_size;
struct selected_region selected_region;
/* offset of the buffer from the start of this struct */
uint32_t buffer_offset;
uint32_t buffer_size;
@ -61,6 +65,30 @@ static size_t vb2_working_data_size(void)
return _vboot2_work_size;
}
static struct selected_region *vb2_selected_region(void)
{
struct selected_region *sel_reg = NULL;
/* Ramstage always uses cbmem as a source of truth. */
if (ENV_RAMSTAGE)
sel_reg = cbmem_find(CBMEM_ID_VBOOT_SEL_REG);
else if (ENV_ROMSTAGE) {
/* Try cbmem first. Fall back on working data if not found. */
sel_reg = cbmem_find(CBMEM_ID_VBOOT_SEL_REG);
if (sel_reg == NULL) {
struct vb2_working_data *wd = vboot_get_working_data();
sel_reg = &wd->selected_region;
}
} else {
/* Stages such as bootblock and verstage use working data. */
struct vb2_working_data *wd = vboot_get_working_data();
sel_reg = &wd->selected_region;
}
return sel_reg;
}
void vb2_init_work_context(struct vb2_context *ctx)
{
struct vb2_working_data *wd;
@ -93,28 +121,57 @@ struct vb2_shared_data *vb2_get_shared_data(void)
int vb2_get_selected_region(struct region_device *rdev)
{
const struct vb2_working_data *wd = vboot_get_working_data();
struct region reg = {
.offset = wd->selected_region_offset,
.size = wd->selected_region_size,
const struct selected_region *reg = vb2_selected_region();
struct region region = {
.offset = reg->offset,
.size = reg->size,
};
return vboot_region_device(&reg, rdev);
return vboot_region_device(&region, rdev);
}
void vb2_set_selected_region(struct region_device *rdev)
{
struct vb2_working_data *wd = vboot_get_working_data();
wd->selected_region_offset = region_device_offset(rdev);
wd->selected_region_size = region_device_sz(rdev);
struct selected_region *reg = vb2_selected_region();
reg->offset = region_device_offset(rdev);
reg->size = region_device_sz(rdev);
}
int vboot_is_slot_selected(void)
{
const struct vb2_working_data *wd = vboot_get_working_data();
return wd->selected_region_size > 0;
const struct selected_region *reg = vb2_selected_region();
return reg->size > 0;
}
int vboot_is_readonly_path(void)
{
return !vboot_is_slot_selected();
}
void vb2_store_selected_region(void)
{
const struct vb2_working_data *wd;
struct selected_region *sel_reg;
/* Always use the working data in this path since it's the object
* which has the result.. */
wd = vboot_get_working_data();
sel_reg = cbmem_add(CBMEM_ID_VBOOT_SEL_REG, sizeof(*sel_reg));
sel_reg->offset = wd->selected_region.offset;
sel_reg->size = wd->selected_region.size;
}
/*
* For platforms that employ VBOOT_DYNAMIC_WORK_BUFFER, the vboot
* verification doesn't happen until after cbmem is brought online.
* Therefore, the selected region contents would not be initialized
* so don't automatically add results when cbmem comes online.
*/
#if !IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER)
static void vb2_store_selected_region_cbmem(int unused)
{
vb2_store_selected_region();
}
ROMSTAGE_CBMEM_INIT_HOOK(vb2_store_selected_region_cbmem)
#endif

View File

@ -39,4 +39,7 @@ void vb2_set_selected_region(struct region_device *rdev);
int vboot_is_slot_selected(void);
int vboot_is_readonly_path(void);
/* Store the selected region in cbmem for later use. */
void vb2_store_selected_region(void);
#endif /* __CHROMEOS_VBOOT2_MISC_H__ */

View File

@ -171,3 +171,17 @@ void vboot_fill_handoff(void)
rdev_munmap(&fw_main, fw_info);
}
/*
* For platforms that employ VBOOT_DYNAMIC_WORK_BUFFER, the vboot
* verification doesn't happen until after cbmem is brought online.
* Therefore, the vboot results would not be initialized so don't
* automatically add results when cbmem comes online.
*/
#if !IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER)
static void vb2_fill_handoff_cbmem(int unused)
{
vboot_fill_handoff();
}
ROMSTAGE_CBMEM_INIT_HOOK(vb2_fill_handoff_cbmem)
#endif

View File

@ -98,10 +98,18 @@ static int vboot_active(struct asset *asset)
return 0;
}
/* Fill in vboot handoff structure before moving to ramstage so all
* downstream users have access to vboot results. */
if (ENV_ROMSTAGE)
/*
* Fill in vboot cbmem objects before moving to ramstage so all
* downstream users have access to vboot results. This path only
* applies to platforms employing VBOOT_DYNAMIC_WORK_BUFFER because
* cbmem comes online prior to vboot verification taking place. For
* other platforms the vboot cbmem objects are initialized when
* cbmem comes online.
*/
if (ENV_ROMSTAGE && IS_ENABLED(CONFIG_VBOOT_DYNAMIC_WORK_BUFFER)) {
vb2_store_selected_region();
vboot_fill_handoff();
}
return vboot_is_slot_selected();
}