diff options
Diffstat (limited to 'contrib/syslinux-4.02/gpxe/src/arch/i386/include/libkir.h')
| -rw-r--r-- | contrib/syslinux-4.02/gpxe/src/arch/i386/include/libkir.h | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/arch/i386/include/libkir.h b/contrib/syslinux-4.02/gpxe/src/arch/i386/include/libkir.h new file mode 100644 index 0000000..1f5b135 --- /dev/null +++ b/contrib/syslinux-4.02/gpxe/src/arch/i386/include/libkir.h @@ -0,0 +1,233 @@ +#ifndef LIBKIR_H +#define LIBKIR_H + +#include "realmode.h" + +#ifndef ASSEMBLY + +/* + * Full API documentation for these functions is in realmode.h. + * + */ + +/* Access to variables in .data16 and .text16 in a way compatible with librm */ +#define __data16( variable ) variable +#define __data16_array( variable, array ) variable array +#define __bss16( variable ) variable +#define __bss16_array( variable, array ) variable array +#define __text16( variable ) variable +#define __text16_array( variable,array ) variable array +#define __use_data16( variable ) variable +#define __use_text16( variable ) variable +#define __from_data16( pointer ) pointer +#define __from_text16( pointer ) pointer + +/* Real-mode data and code segments */ +static inline __attribute__ (( always_inline )) unsigned int _rm_cs ( void ) { + uint16_t cs; + __asm__ __volatile__ ( "movw %%cs, %w0" : "=r" ( cs ) ); + return cs; +} + +static inline __attribute__ (( always_inline )) unsigned int _rm_ds ( void ) { + uint16_t ds; + __asm__ __volatile__ ( "movw %%ds, %w0" : "=r" ( ds ) ); + return ds; +} + +#define rm_cs ( _rm_cs() ) +#define rm_ds ( _rm_ds() ) + +/* Copy to/from base memory */ + +static inline void copy_to_real_libkir ( unsigned int dest_seg, + unsigned int dest_off, + const void *src, size_t n ) { + unsigned int discard_D, discard_S, discard_c; + + __asm__ __volatile__ ( "pushw %%es\n\t" + "movw %3, %%es\n\t" + "rep movsb\n\t" + "popw %%es\n\t" + : "=D" ( discard_D ), "=S" ( discard_S ), + "=c" ( discard_c ) + : "r" ( dest_seg ), "D" ( dest_off ), + "S" ( src ), + "c" ( n ) + : "memory" ); +} + +static inline void copy_from_real_libkir ( void *dest, + unsigned int src_seg, + unsigned int src_off, + size_t n ) { + unsigned int discard_D, discard_S, discard_c; + + __asm__ __volatile__ ( "pushw %%ds\n\t" + "movw %4, %%ds\n\t" + "rep movsb\n\t" + "popw %%ds\n\t" + : "=D" ( discard_D ), "=S" ( discard_S ), + "=c" ( discard_c ) + : "D" ( dest ), + "r" ( src_seg ), "S" ( src_off ), + "c" ( n ) + : "memory" ); +} + +#define copy_to_real copy_to_real_libkir +#define copy_from_real copy_from_real_libkir + +/* + * Transfer individual values to/from base memory. There may well be + * a neater way to do this. We have two versions: one for constant + * offsets (where the mov instruction must be of the form "mov + * %es:123, %xx") and one for non-constant offsets (where the mov + * instruction must be of the form "mov %es:(%xx), %yx". If it's + * possible to incorporate both forms into one __asm__ instruction, I + * don't know how to do it. + * + * Ideally, the mov instruction should be "mov%z0"; the "%z0" is meant + * to expand to either "b", "w" or "l" depending on the size of + * operand 0. This would remove the (minor) ambiguity in the mov + * instruction. However, gcc on at least my system barfs with an + * "internal compiler error" when confronted with %z0. + * + */ + +#define put_real_kir_const_off( var, seg, off ) \ + __asm__ ( "movw %w1, %%es\n\t" \ + "mov %0, %%es:%c2\n\t" \ + "pushw %%ds\n\t" /* restore %es */ \ + "popw %%es\n\t" \ + : \ + : "r,r" ( var ), "rm,rm" ( seg ), "i,!r" ( off ) \ + ) + +#define put_real_kir_nonconst_off( var, seg, off ) \ + __asm__ ( "movw %w1, %%es\n\t" \ + "mov %0, %%es:(%2)\n\t" \ + "pushw %%ds\n\t" /* restore %es */ \ + "popw %%es\n\t" \ + : \ + : "r" ( var ), "rm" ( seg ), "r" ( off ) \ + ) + +#define put_real_kir( var, seg, off ) \ + do { \ + if ( __builtin_constant_p ( off ) ) \ + put_real_kir_const_off ( var, seg, off ); \ + else \ + put_real_kir_nonconst_off ( var, seg, off ); \ + } while ( 0 ) + +#define get_real_kir_const_off( var, seg, off ) \ + __asm__ ( "movw %w1, %%es\n\t" \ + "mov %%es:%c2, %0\n\t" \ + "pushw %%ds\n\t" /* restore %es */ \ + "popw %%es\n\t" \ + : "=r,r" ( var ) \ + : "rm,rm" ( seg ), "i,!r" ( off ) \ + ) + +#define get_real_kir_nonconst_off( var, seg, off ) \ + __asm__ ( "movw %w1, %%es\n\t" \ + "mov %%es:(%2), %0\n\t" \ + "pushw %%ds\n\t" /* restore %es */ \ + "popw %%es\n\t" \ + : "=r" ( var ) \ + : "rm" ( seg ), "r" ( off ) \ + ) + +#define get_real_kir( var, seg, off ) \ + do { \ + if ( __builtin_constant_p ( off ) ) \ + get_real_kir_const_off ( var, seg, off ); \ + else \ + get_real_kir_nonconst_off ( var, seg, off ); \ + } while ( 0 ) + +#define put_real put_real_kir +#define get_real get_real_kir + +/** + * A pointer to a user buffer + * + * This is actually a struct segoff, but encoded as a uint32_t to + * ensure that gcc passes it around efficiently. + */ +typedef uint32_t userptr_t; + +/** + * Copy data to user buffer + * + * @v buffer User buffer + * @v offset Offset within user buffer + * @v src Source + * @v len Length + */ +static inline __attribute__ (( always_inline )) void +copy_to_user ( userptr_t buffer, off_t offset, const void *src, size_t len ) { + copy_to_real ( ( buffer >> 16 ), ( ( buffer & 0xffff ) + offset ), + src, len ); +} + +/** + * Copy data from user buffer + * + * @v dest Destination + * @v buffer User buffer + * @v offset Offset within user buffer + * @v len Length + */ +static inline __attribute__ (( always_inline )) void +copy_from_user ( void *dest, userptr_t buffer, off_t offset, size_t len ) { + copy_from_real ( dest, ( buffer >> 16 ), + ( ( buffer & 0xffff ) + offset ), len ); +} + +/** + * Convert segment:offset address to user buffer + * + * @v segment Real-mode segment + * @v offset Real-mode offset + * @ret buffer User buffer + */ +static inline __attribute__ (( always_inline )) userptr_t +real_to_user ( unsigned int segment, unsigned int offset ) { + return ( ( segment << 16 ) | offset ); +} + +/** + * Convert virtual address to user buffer + * + * @v virtual Virtual address + * @ret buffer User buffer + * + * This constructs a user buffer from an ordinary pointer. Use it + * when you need to pass a pointer to an internal buffer to a function + * that expects a @c userptr_t. + */ +static inline __attribute__ (( always_inline )) userptr_t +virt_to_user ( void * virtual ) { + return real_to_user ( rm_ds, ( intptr_t ) virtual ); +} + +/* TEXT16_CODE: declare a fragment of code that resides in .text16 */ +#define TEXT16_CODE( asm_code_str ) \ + ".section \".text16\", \"ax\", @progbits\n\t" \ + ".code16\n\t" \ + ".arch i386\n\t" \ + asm_code_str "\n\t" \ + ".code16gcc\n\t" \ + ".previous\n\t" + +/* REAL_CODE: declare a fragment of code that executes in real mode */ +#define REAL_CODE( asm_code_str ) \ + ".code16\n\t" \ + asm_code_str "\n\t" \ + ".code16gcc\n\t" + +#endif /* ASSEMBLY */ + +#endif /* LIBKIR_H */ |