Merge branch 'master' into openslxopenslx

1 files changed, 163 insertions, 0 deletions

diff --git a/src/core/spcr.c b/src/core/spcr.c
new file mode 100644
index 000000000..b1cee1608
--- /dev/null
+++ b/src/core/spcr.c
@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2025 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <errno.h>
+#include <ipxe/serial.h>
+#include <ipxe/pci.h>
+#include <ipxe/ns16550.h>
+#include <ipxe/spcr.h>
+
+/** @file
+ *
+ * ACPI Serial Port Console Redirection (SPCR)
+ *
+ */
+
+#ifdef SERIAL_SPCR
+#define SERIAL_PREFIX_spcr
+#else
+#define SERIAL_PREFIX_spcr __spcr_
+#endif
+
+/** SPCR-defined UART */
+static struct uart spcr_uart = {
+	.refcnt = REF_INIT ( ref_no_free ),
+	.name = "SPCR",
+};
+
+/** SPCR-defined 16550 UART */
+static struct ns16550_uart spcr_ns16550 = {
+	.clock = NS16550_CLK_DEFAULT,
+};
+
+/** Base baud rate for SPCR divisors */
+#define SPCR_BAUD_BASE 115200
+
+/** SPCR baud rate divisors */
+static const uint8_t spcr_baud_divisor[SPCR_BAUD_MAX] = {
+	[SPCR_BAUD_2400] = ( SPCR_BAUD_BASE / 2400 ),
+	[SPCR_BAUD_4800] = ( SPCR_BAUD_BASE / 4800 ),
+	[SPCR_BAUD_9600] = ( SPCR_BAUD_BASE / 9600 ),
+	[SPCR_BAUD_19200] = ( SPCR_BAUD_BASE / 19200 ),
+	[SPCR_BAUD_38400] = ( SPCR_BAUD_BASE / 38400 ),
+	[SPCR_BAUD_57600] = ( SPCR_BAUD_BASE / 57600 ),
+	[SPCR_BAUD_115200] = ( SPCR_BAUD_BASE / 115200 ),
+};
+
+/**
+ * Configure 16550-based serial console
+ *
+ * @v spcr		SPCR table
+ * @v uart		UART to configure
+ * @ret rc		Return status code
+ */
+static int spcr_16550 ( struct spcr_table *spcr, struct uart *uart ) {
+	struct ns16550_uart *ns16550 = &spcr_ns16550;
+
+	/* Set base address */
+	ns16550->base = acpi_ioremap ( &spcr->base, NS16550_LEN );
+	if ( ! ns16550->base ) {
+		DBGC ( uart, "SPCR could not map registers\n" );
+		return -ENODEV;
+	}
+
+	/* Set clock frequency, if specified */
+	if ( spcr->clock )
+		ns16550->clock = le32_to_cpu ( spcr->clock );
+
+	/* Configure UART as a 16550 */
+	uart->op = &ns16550_operations;
+	uart->priv = ns16550;
+
+	return 0;
+}
+
+/**
+ * Identify default serial console
+ *
+ * @ret uart		Default serial console UART, or NULL
+ */
+static struct uart * spcr_console ( void ) {
+	struct uart *uart = &spcr_uart;
+	struct spcr_table *spcr;
+	unsigned int baud;
+	int rc;
+
+	/* Locate SPCR table */
+	spcr = container_of ( acpi_table ( SPCR_SIGNATURE, 0 ),
+			      struct spcr_table, acpi );
+	if ( ! spcr ) {
+		DBGC ( uart, "SPCR found no table\n" );
+		goto err_table;
+	}
+	DBGC2 ( uart, "SPCR found table:\n" );
+	DBGC2_HDA ( uart, 0, spcr, sizeof ( *spcr ) );
+	DBGC ( uart, "SPCR is type %d at %02x:%08llx\n",
+	       spcr->type, spcr->base.type,
+	       ( ( unsigned long long ) le64_to_cpu ( spcr->base.address ) ) );
+	if ( spcr->pci_vendor_id != cpu_to_le16 ( PCI_ANY_ID ) ) {
+		DBGC ( uart, "SPCR is PCI " PCI_FMT " (%04x:%04x)\n",
+		       spcr->pci_segment, spcr->pci_bus, spcr->pci_dev,
+		       spcr->pci_func, le16_to_cpu ( spcr->pci_vendor_id ),
+		       le16_to_cpu ( spcr->pci_device_id ) );
+	}
+
+	/* Get baud rate */
+	baud = 0;
+	if ( le32_to_cpu ( spcr->acpi.length ) >=
+	     ( offsetof ( typeof ( *spcr ), precise ) +
+	       sizeof ( spcr->precise ) ) ) {
+		baud = le32_to_cpu ( spcr->precise );
+		if ( baud )
+			DBGC ( uart, "SPCR has precise baud rate %d\n", baud );
+	}
+	if ( ( ! baud ) && spcr->baud && ( spcr->baud < SPCR_BAUD_MAX ) ) {
+		baud = ( SPCR_BAUD_BASE / spcr_baud_divisor[spcr->baud] );
+		DBGC ( uart, "SPCR has baud rate %d\n", baud );
+	}
+	uart->baud = baud;
+
+	/* Initialise according to type */
+	switch ( spcr->type ) {
+	case SPCR_TYPE_16550:
+	case SPCR_TYPE_16450:
+	case SPCR_TYPE_16550_GAS:
+		if ( ( rc = spcr_16550 ( spcr, uart ) ) != 0 )
+			goto err_type;
+		break;
+	default:
+		DBGC ( uart, "SPCR unsupported type %d\n", spcr->type );
+		goto err_type;
+	}
+
+	return uart;
+
+ err_type:
+ err_table:
+	/* Fall back to using fixed serial console */
+	return fixed_serial_console();
+}
+
+PROVIDE_SERIAL ( spcr, default_serial_console, spcr_console );