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GMMOS: I2C keyboards, and every keyboard at once

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The second micro driver: i2c_hid.c with everything but reading a
keyboard's input reports taken out. No ACPI -- AML cannot run on a dead
kernel -- so the live driver hands over what it found at boot
(i2c_hid_keyboards): the DesignWare controller, the address, the report
size, the AMD GPIO pin if there is one, and the parsed report descriptor.
No power commands, no reset, a read-only transfer.

usb_hid.c's report-protocol rewrite is split out as hid_boot_report(),
which does nothing but rewrite, and kernel/gmmos/hidkeys.c turns boot
reports into keys for this and the USB micro drivers to come.

GMMOS now probes every micro driver and polls all that answer.

Not run: QEMU has no DesignWare I2C, and the laptops at hand have PS/2
keyboards.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S1giNvrHTrPMPw7V6x1kQ4
This commit is contained in:
Nexoniarz 2026-10-25 01:15:50 +02:00
commit c6d90e69fa
8 changed files with 387 additions and 17 deletions
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7
include/dev/hid.h
View file

@ -12,6 +12,13 @@ void *hid_attach(const uchar *desc, int n, const char *what);
// One input report, report ID included when the device uses them.
void hid_attached_input(void *h, const uchar *rep, int len);
// For GMMOS, after a panic: whether a device is a keyboard, and one of its
// reports rewritten into the 8-byte boot layout (modifiers, reserved, six
// usages) with nothing else done -- no queue, no lock, no events. 0 when the
// report was not a keyboard's.
int hid_is_keyboard(void *h);
int hid_boot_report(void *h, const uchar *rep, int len, uchar *boot);
// I2C-HID: the touchpads (and some keyboards) of laptops. Started once ACPI
// and kernel threads are up; see kernel/drivers/i2c/i2c_hid.c.
void i2c_hid_start(void);

27
include/gmmos/gmmos.h
View file

@ -31,6 +31,33 @@ struct gmmos_kbd {
};
extern const struct gmmos_kbd gmmos_ps2;
extern const struct gmmos_kbd gmmos_i2c;
// A USB or I2C keyboard report in the boot layout -- modifiers, a reserved
// byte, six usages -- turned into keys. A report is a state, not an event, so
// a key is a usage that was not in the previous one. kernel/gmmos/hidkeys.c.
struct gmmos_hidkeys {
uchar prev[8];
int q[16];
int qh, qt;
};
void gmmos_hid_report(struct gmmos_hidkeys *k, const uchar *boot);
int gmmos_hid_next(struct gmmos_hidkeys *k);
// I2C keyboards, as kernel/acpi/i2c_hid.c found them at boot. GMMOS cannot run
// ACPI to find them again, so the live driver hands over what it learnt: the
// DesignWare controller, the device's address, its input report size, the
// interrupt pin when there is one, and the parsed report descriptor.
struct gmmos_i2c_kbd {
volatile uint32 *regs;
int txdepth, rxdepth;
int addr;
uint32 maxin;
volatile uint32 *pin; // AMD GPIO pin register, or 0: poll blindly
int active_low;
void *hid;
};
int i2c_hid_keyboards(struct gmmos_i2c_kbd *out, int max);
// From kernel/core/panic.c: draw the report again, and where its closing
// lines are, which GMMOS writes its status and its keys into.