From 1730015199921ff775f2b99ca7bd56c879ef534f Mon Sep 17 00:00:00 2001 From: geijoenr Date: Sat, 21 Feb 2015 19:19:03 +0000 Subject: [PATCH] msx2: switch to R800 cpu on boot if available We want to boot fast on TurboR. --- Kernel/platform-msx2/bootrom.s | 8 ++++++++ Kernel/platform-msx2/msx2.def | 4 ++++ 2 files changed, 12 insertions(+) diff --git a/Kernel/platform-msx2/bootrom.s b/Kernel/platform-msx2/bootrom.s index f171737f..0a9a10c8 100644 --- a/Kernel/platform-msx2/bootrom.s +++ b/Kernel/platform-msx2/bootrom.s @@ -23,6 +23,14 @@ bootstrap: di ld sp,#0xf340 ; temporary stack + ; + ; enable R800 CPU if available + ; + ld a,(BIOS_CHGCPU) + cp #0xC3 + ld a,#0x81 ; run only in rom mode, as we do not use BIOS better save 4 ram pages + call z,#BIOS_CHGCPU + ; FIXME: init vdp using bios so that font is in place after vdpinit ld a,#0x50 ld (0xf3ae),a diff --git a/Kernel/platform-msx2/msx2.def b/Kernel/platform-msx2/msx2.def index ae36d01d..11f30892 100644 --- a/Kernel/platform-msx2/msx2.def +++ b/Kernel/platform-msx2/msx2.def @@ -40,4 +40,8 @@ BIOS_VDP_IOPORT .equ 0x0006 OPENMSX_DEBUG1 .equ 0x2E OPENMSX_DEBUG2 .equ 0x2F +; +; TurboR CPU mode select +; +BIOS_CHGCPU .equ 0x180 -- 2.34.1