From 2d59766eb330b9d15a9bcbcd7e1695809fc099c5 Mon Sep 17 00:00:00 2001 From: EmulatedSeasons <89668582+EmulatedSeasons@users.noreply.github.com> Date: Fri, 3 May 2024 03:39:47 -0400 Subject: renamed i386 to x86 --- kernel/arch/x86/gdt2.cpp | 51 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100644 kernel/arch/x86/gdt2.cpp (limited to 'kernel/arch/x86/gdt2.cpp') diff --git a/kernel/arch/x86/gdt2.cpp b/kernel/arch/x86/gdt2.cpp new file mode 100644 index 0000000..0acdb0e --- /dev/null +++ b/kernel/arch/x86/gdt2.cpp @@ -0,0 +1,51 @@ +#include +#include +/* +// structure to be encoded at encodeGdtEntry() +struct GDT +{ + uint32_t base; + uint32_t limit; + uint8_t access_byte; + uint8_t flags; +}; + +GDT strnulldesc {0, 0, 0, 0}; +GDT strkernelcode {0, 0xFFFFF, 0x9A, 0xC}; +GDT strkerneldata {0, 0xFFFFF, 0x92, 0xC}; +GDT strusercode {0, 0xFFFFF, 0xFA, 0xC}; +GDT struserdata {0, 0xFFFFF, 0xF2, 0xC}; + +uint8_t* nulldesc; +uint8_t* kernelcode; +uint8_t* kerneldata; +uint8_t* usercode; +uint8_t* userdata; + + +void encodeGdtEntry(uint8_t *target, struct GDT source) +{ + // Check the limit to make sure that it can be encoded + if (source.limit > 0xFFFFF) {printf("GDT cannot encode limits larger than 0xFFFFF\n");} + + // Encode the limit + target[0] = source.limit & 0xFF; + target[1] = (source.limit >> 8) & 0xFF; + target[6] = (source.limit >> 16) & 0x0F; + + // Encode the base + target[2] = source.base & 0xFF; + target[3] = (source.base >> 8) & 0xFF; + target[4] = (source.base >> 16) & 0xFF; + target[7] = (source.base >> 24) & 0xFF; + + // Encode the access byte + target[5] = source.access_byte; + + // Encode the flags + target[6] |= (source.flags << 4); +} + +extern "C" void setupGdt() { + +} */ \ No newline at end of file -- cgit v1.2.3-70-g09d2