From: Michael Brown <mcb30@ipxe.org>
Date: Wed, 5 Nov 2025 20:06:53 +0000 (+0000)
Subject: [spcr] Accept alternative type value for a 16550-compatible UART
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=HEAD;p=thirdparty%2Fipxe.git

[spcr] Accept alternative type value for a 16550-compatible UART

Some systems (observed on an AWS EC2 m7i.metal-24xl instance in
eu-south-2) use the newer "16550-compatible with parameters defined in
Generic Address Structure" type value.  (There does not appear to be
any particular reason why the newer value needs to be used: the UART
is still a standard 16550 with single-byte registers.)

Accept this additional type value for a 16550-compatible UART.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---

diff --git a/src/core/spcr.c b/src/core/spcr.c
index 88914cac7..b1cee1608 100644
--- a/src/core/spcr.c
+++ b/src/core/spcr.c
@@ -143,6 +143,7 @@ static struct uart * spcr_console ( void ) {
 	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;
diff --git a/src/include/ipxe/spcr.h b/src/include/ipxe/spcr.h
index ff41a4b89..366092ade 100644
--- a/src/include/ipxe/spcr.h
+++ b/src/include/ipxe/spcr.h
@@ -74,6 +74,7 @@ struct spcr_table {
 /* SPCR interface types */
 #define SPCR_TYPE_16550		0x0000		/**< 16550-compatible */
 #define SPCR_TYPE_16450		0x0001		/**< 16450-compatible */
+#define SPCR_TYPE_16550_GAS	0x0012		/**< 16550-compatible */
 
 /** SPCR baud rates */
 enum spcr_baud {