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| author | Simon Glass <sjg@chromium.org> | 2021-02-06 14:23:42 -0700 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2021-03-02 15:53:37 -0500 |
| commit | 63af92e837f3d7c21ab5fc4a96ffcbf202efaf90 (patch) | |
| tree | 6cef337796d50552504a3f0b90e07d32d2d88190 /lib | |
| parent | 7785bc1d5f94d28497bef6935ecbaa1b0ddd3e26 (diff) | |
| download | u-boot-63af92e837f3d7c21ab5fc4a96ffcbf202efaf90.tar.gz u-boot-63af92e837f3d7c21ab5fc4a96ffcbf202efaf90.tar.xz u-boot-63af92e837f3d7c21ab5fc4a96ffcbf202efaf90.zip | |
tpm: Allow disabling platform hierarchy with TPM2
With TPM2 we don't actually lock the TPM once verified boot is finished.
Instead we disable the platform hierarchy which serves the same purpose.
Add an implementation of this so we can safely boot into the kernel.
Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/tpm-v2.c | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c index b796004930..235f8c20d4 100644 --- a/lib/tpm-v2.c +++ b/lib/tpm-v2.c @@ -624,3 +624,38 @@ u32 tpm2_write_lock(struct udevice *dev, u32 index) return tpm_sendrecv_command(dev, command_v2, NULL, NULL); } + +u32 tpm2_disable_platform_hierarchy(struct udevice *dev) +{ + struct tpm_chip_priv *priv = dev_get_uclass_priv(dev); + u8 command_v2[COMMAND_BUFFER_SIZE] = { + /* header 10 bytes */ + tpm_u16(TPM2_ST_SESSIONS), /* TAG */ + tpm_u32(10 + 4 + 13 + 5), /* Length */ + tpm_u32(TPM2_CC_HIER_CONTROL), /* Command code */ + + /* 4 bytes */ + tpm_u32(TPM2_RH_PLATFORM), /* Primary platform seed */ + + /* session header 9 bytes */ + tpm_u32(9), /* Header size */ + tpm_u32(TPM2_RS_PW), /* Password authorisation */ + tpm_u16(0), /* nonce_size */ + 0, /* session_attrs */ + tpm_u16(0), /* auth_size */ + + /* payload 5 bytes */ + tpm_u32(TPM2_RH_PLATFORM), /* Hierarchy to disable */ + 0, /* 0=disable */ + }; + int ret; + + ret = tpm_sendrecv_command(dev, command_v2, NULL, NULL); + log_info("ret=%s, %x\n", dev->name, ret); + if (ret) + return ret; + + priv->plat_hier_disabled = true; + + return 0; +} |