1 // 2 // assembler macros to create x86 segments 3 // 4 5 #define SEG_NULLASM \ 6 .word 0, 0; \ 7 .byte 0, 0, 0, 0 8 9 // The 0xC0 means the limit is in 4096-byte units 10 // and (for executable segments) 32-bit mode. 11 #define SEG_ASM(type,base,lim) \ 12 .word (((lim) >> 12) & 0xffff), ((base) & 0xffff); \ 13 .byte (((base) >> 16) & 0xff), (0x90 | (type)), \ 14 (0xC0 | (((lim) >> 28) & 0xf)), (((base) >> 24) & 0xff) 15 16 #define STA_X 0x8 // Executable segment 17 #define STA_W 0x2 // Writeable (non-executable segments) 18 #define STA_R 0x2 // Readable (executable segments) 19