arch: m68k: Add QEMU specific RAMBAR workaround
The QEMU emulation of m68k does not support RAMBAR accesses,
add Kconfig option which inhibits those accesses, so that
U-Boot can be started in m68k QEMU for CI testing purpopses
until QEMU emulation improves.
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 32759cd..1911563 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -198,8 +198,17 @@
source "board/sysam/amcore/Kconfig"
source "board/sysam/stmark2/Kconfig"
+config M68K_QEMU
+ bool "Build with workarounds for incomplete QEMU emulation"
+ default n
+ help
+ QEMU 8.x currently does not implement RAMBAR accesses and
+ DMA timers. Enable this option for U-Boot CI purposes only
+ to skip the RAMBAR accesses.
+
config MCFTMR
bool "Use DMA timer"
- default y
+ default y if !M68K_QEMU
+ default n if M68K_QEMU
endmenu
diff --git a/arch/m68k/cpu/mcf52x2/start.S b/arch/m68k/cpu/mcf52x2/start.S
index d48d019..51d2e23 100644
--- a/arch/m68k/cpu/mcf52x2/start.S
+++ b/arch/m68k/cpu/mcf52x2/start.S
@@ -98,7 +98,7 @@
nop
move.w #0x2700,%sr
-#if defined(CONFIG_M5208)
+#if defined(CONFIG_M5208) && !defined(CONFIG_M68K_QEMU)
/* Initialize RAMBAR: locate SRAM and validate it */
move.l #(CFG_SYS_INIT_RAM_ADDR + CFG_SYS_INIT_RAM_CTRL), %d0
movec %d0, %RAMBAR1
@@ -120,7 +120,7 @@
movec %d0, %RAMBAR0
#endif /* CONFIG_M5272 || CONFIG_M5249 || CONFIG_M5253 */
-#if defined(CONFIG_M5282) || defined(CONFIG_M5271)
+#if (defined(CONFIG_M5282) || defined(CONFIG_M5271)) && !defined(CONFIG_M68K_QEMU)
/* set MBAR address + valid flag */
move.l #(CFG_SYS_MBAR + 1), %d0
move.l %d0, 0x40000000