libpayload: Add mock architecture

Mock architecture can be used to build libpayload using host compiler.
It can be enabled by setting ARCH_MOCK=y in the dotconfig. It sets
LITTLE_ENDIAN=y, as most machines these days use little-endian CPUs.
Libpayload will use HOSTCC as CC, HOSTLD as LD, etc. instead of tools
provided by xcompile.
Mock architecture configuration can be used by payloads for testing
purposes. Thanks to it, tests can be architecture-independent,
and can be executed without requiring compatible Kconfig options,
e.g. ARCH_ARM64=y for ARM64 machine. However, one has to provide
implementation for most architecture-specific functions present
in arch/* directories.

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: Ie3a6e6f6cad2f8a2e48a8e546d3b79c577653080
Reviewed-on: https://review.coreboot.org/c/coreboot/+/57708
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

5 files changed, 108 insertions, 0 deletions

diff --git a/payloads/libpayload/include/mock/arch/barrier.h b/payloads/libpayload/include/mock/arch/barrier.h
new file mode 100644
index 0000000000..aed115bb64
--- /dev/null
+++ b/payloads/libpayload/include/mock/arch/barrier.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ARCH_BARRIER_H__
+#define __ARCH_BARRIER_H__
+
+/* No memory barrier on mock build */
+#define mb()
+/* No read memory barrier on mock build */
+#define rmb()
+/* No write memory barrier on mock build */
+#define wmb()
+
+#endif /* __ARCH_BARRIER_H__ */
diff --git a/payloads/libpayload/include/mock/arch/cache.h b/payloads/libpayload/include/mock/arch/cache.h
new file mode 100644
index 0000000000..1e71d5e0e2
--- /dev/null
+++ b/payloads/libpayload/include/mock/arch/cache.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __ARCH_CACHE_H__
+#define __ARCH_CACHE_H__
+
+/* No support for cache in the mock architecture */
+
+#define dmb()
+#define dsb()
+#define dcache_clean_all()
+#define dcache_clean_by_mva(addr, len)
+#define dcache_invalidate_all()
+#define dcache_invalidate_by_mva(addr, len)
+#define dcache_clean_invalidate_all()
+#define dcache_clean_invalidate_by_mva(addr, len)
+#define cache_sync_instructions()
+
+#endif /* __ARCH_CACHE_H__ */
diff --git a/payloads/libpayload/include/mock/arch/io.h b/payloads/libpayload/include/mock/arch/io.h
new file mode 100644
index 0000000000..2bb625562e
--- /dev/null
+++ b/payloads/libpayload/include/mock/arch/io.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ARCH_IO_H
+#define _ARCH_IO_H
+
+#include <inttypes.h>
+
+/* Functions in this file are unimplemented by default. Tests are expected to implement
+   mocks for these functions, if tests will call functions using functions listed below. */
+
+uint8_t readb(volatile const void *_a);
+uint16_t readw(volatile const void *_a);
+uint32_t readl(volatile const void *_a);
+
+void writeb(uint8_t _v, volatile void *_a);
+void writew(uint16_t _v, volatile void *_a);
+void writel(uint32_t _v, volatile void *_a);
+
+uint8_t read8(volatile const void *addr);
+uint16_t read16(volatile const void *addr);
+uint32_t read32(volatile const void *addr);
+uint64_t read64(volatile const void *addr);
+
+void write8(volatile void *addr, uint8_t val);
+void write16(volatile void *addr, uint16_t val);
+void write32(volatile void *addr, uint32_t val);
+void write64(volatile void *addr, uint64_t val);
+
+#endif /* _ARCH_IO_H */
diff --git a/payloads/libpayload/include/mock/arch/types.h b/payloads/libpayload/include/mock/arch/types.h
new file mode 100644
index 0000000000..8f090caa9b
--- /dev/null
+++ b/payloads/libpayload/include/mock/arch/types.h
@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ARCH_TYPES_H
+#define _ARCH_TYPES_H
+
+typedef unsigned char uint8_t;
+typedef unsigned char u8;
+typedef signed char int8_t;
+typedef signed char s8;
+
+typedef unsigned short uint16_t;
+typedef unsigned short u16;
+typedef signed short int16_t;
+typedef signed short s16;
+
+typedef unsigned int uint32_t;
+typedef unsigned int u32;
+typedef signed int int32_t;
+typedef signed int s32;
+
+typedef unsigned long long uint64_t;
+typedef unsigned long long u64;
+typedef signed long long int64_t;
+typedef signed long long s64;
+
+typedef long time_t;
+typedef long suseconds_t;
+
+#ifndef NULL
+#define NULL ((void *)0)
+#endif
+
+#endif /* _ARCH_TYPES_H */
diff --git a/payloads/libpayload/include/mock/arch/virtual.h b/payloads/libpayload/include/mock/arch/virtual.h
new file mode 100644
index 0000000000..bf786d5256
--- /dev/null
+++ b/payloads/libpayload/include/mock/arch/virtual.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _ARCH_VIRTUAL_H
+#define _ARCH_VIRTUAL_H
+
+/* virtual_offset has to be declared if used */
+extern unsigned long virtual_offset;
+
+#define virt_to_phys(virt) ((unsigned long)(virt) + virtual_offset)
+#define phys_to_virt(phys) ((void *)((unsigned long)(phys) - virtual_offset))
+
+#define virt_to_bus(addr) virt_to_phys(addr)
+#define bus_to_virt(addr) phys_to_virt(addr)
+
+#endif