swtpm_bios(8)

💖 swtpm_bios(8) — the BIOS-simulator bestie 💖

Okay so picture this: it's swtpm_bios, the manual page, and she's here to explain the tool that does the BIOS's little TPM warm-up routine. Iykyk.

✨ NAME ✨

swtpm_bios — a BIOS simulation tool for swtpm, fr fr 🌸

🎀 SYNOPSIS 🎀

swtpm_bios [OPTIONS]

🦋 DESCRIPTION 🦋

So swtpm_bios is that girl 💅 — she sends the exact commands to the TPM (that's the swtpm program) that the BIOS typically uses to initialize the TPM. And you get options, bestie — several command line options — to pick which state you want the TPM set to. Choose your fighter. ✨

Heads up, queen 👑: this command requires the environment variable TCSD_USE_TCP_DEVICE to be set if you're communicating via TCP. No variable, no TCP. Periodt.

If you're not doing TCP, it'll use the device set in the environment variable TPM_DEVICE, or fall back to /dev/tpm0 for sending the commands. Slight "we'll figure it out" energy, but okay.

In TCP mode, the environment variable TCSD_TCP_DEVICE_HOSTNAME tells it which host to send the commands to. Default assumption is localhost. And the default TCP port is 6545 — unless the environment variable TCSD_TCP_DEVICE_PORT says otherwise. 💫

🌈 Return codes (vibe check) 🌈

• 0 — success, we ate 🍓
• 128 — a TPM error was encountered 😭
• 255 — communication failure 💀
• 129 — the TPM needs to be reset to become activated 🙈

🌸 The command sequence it sends 🌸

This command will send the following sequence of commands to the TPM:

TPM_Startup(chosen mode) -- startup TPM
TSC_PhysicalPresence(0x20) -- PhysicalPresenceCMDEnable
TSC_PhysicalPresence(0x08) -- turn on physical presence
TPM_GetCapability -- get permanent flags
TPM_PhysicalEnable -- enable the TPM
TPM_PhysicalSetDeactivated(0x0) -- activate TPM
TPM_ContinueSelfTest -- continue self test
TSC_PhysicalPresence(0x20) -- PhysicalPresenceCMDEnable
TSC_PhysicalPresence(0x14) -- turn off physical presence & lock it

Lowkey iconic lineup. 🔥

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💜 OPTIONS 💜

The following options are supported:

• --tpm-device <device> — use the given device instead of the default /dev/tpm0. This one overrides the TPM_DEVICE environment variable, so she's got main character energy over that env var. 🎀
• --tcp <server>:<port> — connect to the given server and port. No server given? Then 127.0.0.1 is used. No port given? Then the default port 6545 is used. Flexible queen. ✨
• --unix <path> — connect to the given UnixIO path. 🦋
• -tpm2 — the device is a TPM 2. Noted, bestie.
• -c — send TPM_Startup(ST_CLEAR) (default). This instructs the TPM to start with clear state. Fresh start, clean slate, we love it. 🌸
• -s — send TPM_Startup(ST_STATE). This instructs the TPM to start by restoring previously saved state. Nostalgic era. 💫
• -d — send TPM_Startup(ST_DEACTIVATED). This instructs the TPM to start in deactivated mode. ⚠️ This option has no effect on a TPM 2 — so don't come for her if nothing happens.
• -n — don't send a TPM_Startup command. Skipping it, respectfully. 🙈
• -o — only send the startup command and nothing else. Minimalist icon. 💅
• -ea — make sure that the TPM is activated; if the TPM requires a reset, the program will exist and return a return code of 129. 💀 (That's exactly how the original words it — "the program will exist" — so yes, you read that right.)
• -cs — send a TPM_ContinueSelfTest command to a TPM 1.2 and a TPM2_IncrementalSelfTest command to a TPM 2. Knows both dialects, bilingual legend. 🌈
• -u — give up physical presence on a TPM 1.2. In case of a TPM 2, set the platform hierarchy to a random password. Random password era 🔐✨
• -v — display version and exit. Bye bestie 👋
• -h — display the help screen and exit. 🫶

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👀 SEE ALSO 👀

(Yeah… the original leaves this one empty. Nothing to see here. Moving on. 💀)

🐛 REPORTING BUGS 🐛

Report bugs to Stefan Berger <stefanb@linux.vnet.ibm.com> — be nice, be specific, include the deets. 🫶

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Mwah 💖 that's the whole page! This lil swtpm_bios(8) situation comes from the swtpm source, dated 2026-08-23 — go forth and initialize those TPMs, bestie. ✨🎀🦋