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[librm] Add rm stack copying functions

tags/v0.9.4
Daniel Verkamp 16 年前
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共有 2 个文件被更改,包括 48 次插入0 次删除
  1. 3
    0
      src/arch/i386/include/librm.h
  2. 45
    0
      src/arch/i386/transitions/librm_mgmt.c

+ 3
- 0
src/arch/i386/include/librm.h 查看文件

@@ -279,6 +279,9 @@ user_to_phys ( userptr_t buffer, off_t offset ) {
279 279
 	return virt_to_phys ( ( void * ) buffer + offset );
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 }
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+extern uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size );
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+extern void remove_user_from_rm_stack ( userptr_t data, size_t size );
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+
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 /* TEXT16_CODE: declare a fragment of code that resides in .text16 */
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 #define TEXT16_CODE( asm_code_str )			\
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 	".section \".text16\", \"ax\", @progbits\n\t"	\

+ 45
- 0
src/arch/i386/transitions/librm_mgmt.c 查看文件

@@ -0,0 +1,45 @@
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+/*
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+ * librm: a library for interfacing to real-mode code
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+ *
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+ * Michael Brown <mbrown@fensystems.co.uk>
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+ *
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+ */
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+
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+#include <stdint.h>
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+#include <librm.h>
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+
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+/*
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+ * This file provides functions for managing librm.
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+ *
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+ */
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+
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+/**
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+ * Allocate space on the real-mode stack and copy data there from a
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+ * user buffer
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+ *
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+ * @v data			User buffer
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+ * @v size			Size of stack data
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+ * @ret sp			New value of real-mode stack pointer
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+ */
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+uint16_t copy_user_to_rm_stack ( userptr_t data, size_t size ) {
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+	userptr_t rm_stack;
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+	rm_sp -= size;
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+	rm_stack = real_to_user ( rm_ss, rm_sp );
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+	memcpy_user ( rm_stack, 0, data, 0, size );
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+	return rm_sp;
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+};
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+
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+/**
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+ * Deallocate space on the real-mode stack, optionally copying back
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+ * data to a user buffer.
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+ *
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+ * @v data			User buffer
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+ * @v size			Size of stack data
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+ */
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+void remove_user_from_rm_stack ( userptr_t data, size_t size ) {
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+	if ( data ) {
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+		userptr_t rm_stack = real_to_user ( rm_ss, rm_sp );
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+		memcpy_user ( rm_stack, 0, data, 0, size );
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+	}
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+	rm_sp += size;
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+};

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