x86: Add implementations of setjmp() and longjmp()
Bring in these functions from Linux v4.4. They will be needed for EFI loader
support.
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/Makefile b/arch/x86/cpu/Makefile
index 2667e0b..f5b8c9e 100644
--- a/arch/x86/cpu/Makefile
+++ b/arch/x86/cpu/Makefile
@@ -10,7 +10,7 @@
extra-y = start.o
obj-$(CONFIG_X86_RESET_VECTOR) += resetvec.o start16.o
-obj-y += interrupts.o cpu.o cpu_x86.o call64.o
+obj-y += interrupts.o cpu.o cpu_x86.o call64.o setjmp.o
AFLAGS_REMOVE_call32.o := -mregparm=3 \
$(if $(CONFIG_EFI_STUB_64BIT),-march=i386 -m32)
diff --git a/arch/x86/cpu/setjmp.S b/arch/x86/cpu/setjmp.S
new file mode 100644
index 0000000..2ea1c6c
--- /dev/null
+++ b/arch/x86/cpu/setjmp.S
@@ -0,0 +1,61 @@
+/*
+ * Written by H. Peter Anvin <hpa@zytor.com>
+ * Brought in from Linux v4.4 and modified for U-Boot
+ * From Linux arch/um/sys-i386/setjmp.S
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#define _REGPARM
+
+/*
+ * The jmp_buf is assumed to contain the following, in order:
+ * %ebx
+ * %esp
+ * %ebp
+ * %esi
+ * %edi
+ * <return address>
+ */
+
+ .text
+ .align 4
+ .globl setjmp
+ .type setjmp, @function
+setjmp:
+#ifdef _REGPARM
+ movl %eax, %edx
+#else
+ movl 4(%esp), %edx
+#endif
+ popl %ecx /* Return address, and adjust the stack */
+ xorl %eax, %eax /* Return value */
+ movl %ebx, (%edx)
+ movl %esp, 4(%edx) /* Post-return %esp! */
+ pushl %ecx /* Make the call/return stack happy */
+ movl %ebp, 8(%edx)
+ movl %esi, 12(%edx)
+ movl %edi, 16(%edx)
+ movl %ecx, 20(%edx) /* Return address */
+ ret
+
+ /* Provide function size if needed */
+ .size setjmp, .-setjmp
+
+ .align 4
+ .globl longjmp
+ .type longjmp, @function
+longjmp:
+#ifdef _REGPARM
+ xchgl %eax, %edx
+#else
+ movl 4(%esp), %edx /* jmp_ptr address */
+#endif
+ movl (%edx), %ebx
+ movl 4(%edx), %esp
+ movl 8(%edx), %ebp
+ movl 12(%edx), %esi
+ movl 16(%edx), %edi
+ jmp *20(%edx)
+
+ .size longjmp, .-longjmp
diff --git a/arch/x86/include/asm/setjmp.h b/arch/x86/include/asm/setjmp.h
new file mode 100644
index 0000000..1feaa89
--- /dev/null
+++ b/arch/x86/include/asm/setjmp.h
@@ -0,0 +1,24 @@
+/*
+ * Written by H. Peter Anvin <hpa@zytor.com>
+ * Brought in from Linux v4.4 and modified for U-Boot
+ * From Linux arch/um/sys-i386/setjmp.S
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#ifndef __setjmp_h
+#define __setjmp_h
+
+struct jmp_buf_data {
+ unsigned int __ebx;
+ unsigned int __esp;
+ unsigned int __ebp;
+ unsigned int __esi;
+ unsigned int __edi;
+ unsigned int __eip;
+};
+
+int setjmp(struct jmp_buf_data *jmp_buf);
+void longjmp(struct jmp_buf_data *jmp_buf, int val);
+
+#endif