From cf1960dbbd490743029d8864172f6cf4d4d89fc6 Mon Sep 17 00:00:00 2001
From: Ruben Ayrapetyan <r.ayrapetyan@samsung.com>
Date: Thu, 26 Mar 2015 15:50:45 +0300
Subject: [PATCH] Support for 32-bit Linux in Jerry's libc.

---
 build/configs/toolchain_linux_i686.cmake |  19 ++++
 jerry-libc/CMakeLists.txt                |   4 +
 jerry-libc/target/linux/asm_x86.h        | 109 ++++++++++++++---------
 3 files changed, 88 insertions(+), 44 deletions(-)
 create mode 100644 build/configs/toolchain_linux_i686.cmake

diff --git a/build/configs/toolchain_linux_i686.cmake b/build/configs/toolchain_linux_i686.cmake
new file mode 100644
index 000000000..2eabbc8da
--- /dev/null
+++ b/build/configs/toolchain_linux_i686.cmake
@@ -0,0 +1,19 @@
+# Copyright 2015 Samsung Electronics Co., Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_SYSTEM_PROCESSOR x86)
+
+set(CMAKE_C_COMPILER i686-linux-gnu-gcc)
+set(CMAKE_CXX_COMPILER i686-linux-gnu-g++)
diff --git a/jerry-libc/CMakeLists.txt b/jerry-libc/CMakeLists.txt
index 24ef95f7d..f384d926f 100644
--- a/jerry-libc/CMakeLists.txt
+++ b/jerry-libc/CMakeLists.txt
@@ -32,6 +32,8 @@ set(COMPILE_FLAGS_LIBC "${COMPILE_FLAGS_JERRY} ${C_FLAGS_JERRY}")
    set(DEFINES_LIBC_X86_64 __TARGET_HOST_x64)
   # ARMv7
    set(DEFINES_LIBC_ARMV7 __TARGET_HOST_ARMv7)
+  # x86
+   set(DEFINES_LIBC_X86 __TARGET_HOST_x86)
 
  # Platform-specific
   # Linux
@@ -102,6 +104,8 @@ set(COMPILE_FLAGS_LIBC "${COMPILE_FLAGS_JERRY} ${C_FLAGS_JERRY}")
   set(DEFINES_LIBC ${DEFINES_LIBC} ${DEFINES_LIBC_X86_64})
  elseif(${CMAKE_SYSTEM_PROCESSOR} STREQUAL "armv7l")
   set(DEFINES_LIBC ${DEFINES_LIBC} ${DEFINES_LIBC_ARMV7})
+ elseif(${CMAKE_SYSTEM_PROCESSOR} STREQUAL "x86")
+  set(DEFINES_LIBC ${DEFINES_LIBC} ${DEFINES_LIBC_X86})
  else()
   message(FATAL_ERROR "Unsupported machine architecture")
  endif()
diff --git a/jerry-libc/target/linux/asm_x86.h b/jerry-libc/target/linux/asm_x86.h
index cf9815675..c4dcefcee 100644
--- a/jerry-libc/target/linux/asm_x86.h
+++ b/jerry-libc/target/linux/asm_x86.h
@@ -16,57 +16,78 @@
 #ifndef ASM_X86_H
 #define ASM_X86_H
 
-FIXME(Implement x86 ABI);
-#error "Not implemented"
+/*
+ * mov syscall_no -> %eax
+ * mov arg1 -> %ebx
+ * int $0x80
+ * mov %eax -> ret
+ */
+#define SYSCALL_1 \
+  push %edi;               \
+  push %esi;               \
+  push %ebx;               \
+  mov 0x10 (%esp), %eax;   \
+  mov 0x14 (%esp), %ebx;   \
+  int $0x80;               \
+  pop %ebx;                \
+  pop %esi;                \
+  pop %edi;                \
+  ret;
 
 /*
- * mov syscall_no -> %rax
- * mov arg1 -> %rdi
- * syscall
- * mov %rax -> ret
+ * mov syscall_no -> %eax
+ * mov arg1 -> %ebx
+ * mov arg2 -> %ecx
+ * int $0x80
+ * mov %eax -> ret
  */
-#define SYSCALL_1 (syscall_no, arg1, ret) \
-    __asm ("syscall" \
-          : "=a" (ret) \
-          : "a" (syscall_no), "D" (arg1) \
-          : "rcx", "r11");
+#define SYSCALL_2 \
+  push %edi;               \
+  push %esi;               \
+  push %ebx;               \
+  mov 0x10 (%esp), %eax;   \
+  mov 0x14 (%esp), %ebx;   \
+  mov 0x18 (%esp), %ecx;   \
+  int $0x80;               \
+  pop %ebx;                \
+  pop %esi;                \
+  pop %edi;                \
+  ret;
 
 /*
- * mov syscall_no -> %rax
- * mov arg1 -> %rdi
- * mov arg2 -> %rsi
- * syscall
- * mov %rax -> ret
+ * mov syscall_no -> %eax
+ * mov arg1 -> %ebx
+ * mov arg2 -> %ecx
+ * mov arg3 -> %edx
+ * int $0x80
+ * mov %eax -> ret
  */
-#define SYSCALL_2 (syscall_no, arg1, arg2, ret) \
-    __asm ("syscall" \
-          : "=a" (ret) \
-          : "a" (syscall_no), "D" (arg1), "S" (arg2) \
-          : "rcx", "r11");
+#define SYSCALL_3 \
+  push %edi;               \
+  push %esi;               \
+  push %ebx;               \
+  mov 0x10 (%esp), %eax;   \
+  mov 0x14 (%esp), %ebx;   \
+  mov 0x18 (%esp), %ecx;   \
+  mov 0x1c (%esp), %edx;   \
+  int $0x80;               \
+  pop %ebx;                \
+  pop %esi;                \
+  pop %edi;               \
+  ret;
 
-/*
- * mov syscall_no -> %rax
- * mov arg1 -> %rdi
- * mov arg2 -> %rsi
- * mov arg3 -> %rdx
- * syscall
- * mov %rax -> ret
- */
-#define SYSCALL_3 (syscall_no, arg1, arg2, arg3, ret) \
-    __asm ("syscall" \
-          : "=a" (ret) \
-          : "a" (syscall_no), "D" (arg1), "S" (arg2), "d" (arg3) \
-          : "rcx", "r11");
-
-#define _START            \
-   mov (%rsp), %rdi;      \
-   mov %rsp, %rsi;        \
-   add $8, %rsi;          \
-   callq main;            \
-                          \
-   mov %rax, %rdi;        \
-   callq exit;          \
-   1:                     \
+#define _START             \
+   mov %esp, %eax;         \
+   add $4, %eax;           \
+   push %eax;              \
+   mov 0x4 (%esp), %eax;   \
+   push %eax;              \
+                           \
+   call main;              \
+                           \
+   push %eax;              \
+   call exit;              \
+   1:                      \
    jmp 1b
 
 #endif /* !ASM_X86_H */