From 031c44e4deedbd7829703654e381ca0b18e78a12 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 10 Sep 2013 19:09:33 +0100 Subject: pl110: Clarify comment about PL110 ID on VersatilePB Clarify a comment about the ID register value presented by the PL110 variant present on the VersatilePB board (based on testing what the actual hardware does), to indicate that this is not an error in our emulation, and to remove an #if-0. Signed-off-by: Peter Maydell --- hw/display/pl110.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) (limited to 'hw') diff --git a/hw/display/pl110.c b/hw/display/pl110.c index e79ab4bbdd..790e5108ed 100644 --- a/hw/display/pl110.c +++ b/hw/display/pl110.c @@ -94,23 +94,21 @@ static const VMStateDescription vmstate_pl110 = { static const unsigned char pl110_id[] = { 0x10, 0x11, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }; -/* The Arm documentation (DDI0224C) says the CLDC on the Versatile board - has a different ID. However Linux only looks for the normal ID. */ -#if 0 -static const unsigned char pl110_versatile_id[] = -{ 0x93, 0x10, 0x04, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }; -#else -#define pl110_versatile_id pl110_id -#endif - static const unsigned char pl111_id[] = { 0x11, 0x11, 0x24, 0x00, 0x0d, 0xf0, 0x05, 0xb1 }; + /* Indexed by pl110_version */ static const unsigned char *idregs[] = { pl110_id, - pl110_versatile_id, + /* The ARM documentation (DDI0224C) says the CLCDC on the Versatile board + * has a different ID (0x93, 0x10, 0x04, 0x00, ...). However the hardware + * itself has the same ID values as a stock PL110, and guests (in + * particular Linux) rely on this. We emulate what the hardware does, + * rather than what the docs claim it ought to do. + */ + pl110_id, pl111_id }; -- cgit v1.2.1