API tools faq
paste
Advertisement
MichaelPetch

SO78689448-patch1.diff

MichaelPetch
Jul 2nd, 2024 (edited)
68
0
Never
Add comment
Not a member of Pastebin yet? Sign Up, it unlocks many cool features!
text 9.50 KB | None | 0 0
raw download clone embed print report
  1. diff --git a/source/kernel/assembly/bios.asm b/source/kernel/assembly/bios.asm
  2. index 8a3a580..9cf3fc7 100644
  3. --- a/source/kernel/assembly/bios.asm
  4. +++ b/source/kernel/assembly/bios.asm
  5. @@ -26,24 +26,29 @@ section .text
  6.  
  7. ; 32 bit protected mode
  8. BIOS32_START:use32
  9. + pushf
  10. pusha
  11. - ; save current esp to edx
  12. - mov edx, esp
  13. +
  14. + ; Save the original IDTR and GDTR onto the stack
  15. + sub esp, 32
  16. + sidt [esp]
  17. + sgdt [esp+16]
  18. +
  19. + ; save current protected mode esp
  20. + mov [REBASE_ADDRESS(prot_esp)], esp
  21. +
  22. ; jumping to 16 bit protected mode
  23. ; disable interrupts
  24. cli
  25.  
  26. -
  27. ; Turn off paging
  28. - mov cr0, eax
  29. - and eax, DISABLE_PAGING
  30. mov eax, cr0
  31. + and eax, DISABLE_PAGING
  32. + mov cr0, eax
  33.  
  34. - ; Executing this corrupts CR3 (page table index) so save it in EBX
  35. - xor ecx, ecx
  36. - mov ebx, cr3
  37. - mov cr3, ecx
  38. -
  39. + ; Flush TLB
  40. + mov eax, cr3
  41. + mov cr3, eax
  42.  
  43. ; Load GDT
  44. lgdt [REBASE_ADDRESS(bios32_gdt_ptr)]
  45. @@ -97,11 +102,11 @@ __real_mode_16:use16
  46. push cx
  47. pushf
  48. ; get current stack pointer & save it to current_esp
  49. - mov ax, sp
  50. - mov edi, current_esp
  51. - stosw
  52. + mov eax, esp
  53. + mov edi, REBASE_ADDRESS(current_esp)
  54. + stosd
  55. ; load our custom registers context
  56. - mov esp, REBASE_ADDRESS(bios32_in_reg16_ptr)
  57. + mov sp, REBASE_ADDRESS(bios32_in_reg16_ptr)
  58. ; only use some general register from the given context
  59. popa
  60. ; set a new stack for bios interrupt
  61. @@ -129,9 +134,9 @@ bios32_int_number_ptr: ; will be bios interrupt number passed
  62. push cx
  63. pusha
  64. ; restore the current_esp to continue
  65. - mov esi, current_esp
  66. - lodsw
  67. - mov sp, ax
  68. + mov esi, REBASE_ADDRESS(current_esp)
  69. + lodsd
  70. + mov esp, eax
  71. ; restore all current context, all general, segment registers, flags
  72. popf
  73. pop cx
  74. @@ -148,8 +153,9 @@ bios32_int_number_ptr: ; will be bios interrupt number passed
  75.  
  76. ; jumping to 32 bit protected mode
  77. ; set bit 0 in cr0 to 1
  78. + cli
  79. mov eax, cr0
  80. - inc eax
  81. + or eax, ENABLE_PAGING
  82. mov cr0, eax
  83. jmp 0x08:REBASE_ADDRESS(__protected_mode_32)
  84.  
  85. @@ -162,29 +168,26 @@ __protected_mode_32:use32
  86. mov gs, ax
  87. mov ss, ax
  88.  
  89. - ; Restore CR3
  90. - mov cr3, ebx
  91. -
  92. - ; Enable paging
  93. - mov ecx, cr0
  94. - or ecx, ENABLE_PAGING
  95. - mov cr0, ecx
  96. -
  97. ; Restore ESP
  98. - mov esp, edx
  99. + mov esp, [REBASE_ADDRESS(prot_esp)]
  100.  
  101. - sti
  102. + ; Reload the original IDTR and GDTR from the stack
  103. + lidt [esp]
  104. + lgdt [esp+16]
  105. + add esp, 32
  106. +
  107. + ; Restore all registers
  108. popa
  109. +
  110. + ; Restore flags including Interrupt flag state
  111. + popf
  112. ret
  113.  
  114. +align 4
  115.  
  116. -__padding:
  117. - db 0x0
  118. - db 0x0
  119. - db 0x0
  120. bios32_gdt_entries:
  121. ; 8 gdt entries
  122. - resb 64
  123. + TIMES 8 dq 0
  124. bios32_gdt_ptr:
  125. dd 0x00000000
  126. dd 0x00000000
  127. @@ -192,7 +195,7 @@ bios32_idt_ptr:
  128. dd 0x00000000
  129. dd 0x00000000
  130. bios32_in_reg16_ptr:
  131. - resw 14
  132. + TIMES 14 dw 0
  133. bios32_out_reg16_ptr:
  134. dd 0xaaaaaaaa
  135. dd 0xaaaaaaaa
  136. @@ -202,6 +205,8 @@ bios32_out_reg16_ptr:
  137. dd 0xaaaaaaaa
  138. dd 0xaaaaaaaa
  139. current_esp:
  140. - dw 0x0000
  141. + dd 0x0000
  142. +prot_esp:
  143. + dd 0x0000
  144.  
  145. -BIOS32_END:
  146. \ No newline at end of file
  147. +BIOS32_END:
  148. diff --git a/source/kernel/bios32.c b/source/kernel/bios32.c
  149. index 811c432..ec42146 100644
  150. --- a/source/kernel/bios32.c
  151. +++ b/source/kernel/bios32.c
  152. @@ -35,31 +35,27 @@ void bios32_call(uint8_t interrupt, REGISTERS_16 *in, REGISTERS_16 *out) {
  153. // Update the base address of the GDT entries, starting from 0x7C00.
  154. realModeGDT.base_addr = (uint32_t)REBASE_ADDRESS((&bios32_gdt_entries));
  155.  
  156. - // Copy the real mode GDT and IDT to their respective pointers.
  157. - memcpy(&bios32_gdt_ptr, &realModeGDT, sizeof(idtPtr_t));
  158. - memcpy(&bios32_idt_ptr, &realModeIDT, sizeof(idtPtr_t));
  159. -
  160. - // Copy the in registers to their pointers.
  161. - memcpy(&bios32_in_reg16_ptr, in, sizeof(REGISTERS_16));
  162. -
  163. - // Get the in registers' address.
  164. - void *in_reg16_address = REBASE_ADDRESS(&bios32_in_reg16_ptr);
  165. -
  166. - // Copy the BIOS interrupt number to its respective pointer.
  167. - memcpy(&bios32_int_number_ptr, &interrupt, sizeof(uint8_t));
  168. -
  169. + // Copy the real mode GDT and IDT to their respective pointers.
  170. + memcpy(&bios32_gdt_ptr, &realModeGDT, sizeof(idtPtr_t));
  171. + memcpy(&bios32_idt_ptr, &realModeIDT, sizeof(idtPtr_t));
  172. +
  173. + // Copy the in registers to their pointers.
  174. + memcpy(&bios32_in_reg16_ptr, in, sizeof(REGISTERS_16));
  175. +
  176. + // Get the in registers' address.
  177. + void *in_reg16_address = REBASE_ADDRESS(&bios32_in_reg16_ptr);
  178. +
  179. + // Copy the BIOS interrupt number to its respective pointer.
  180. + memcpy(&bios32_int_number_ptr, &interrupt, sizeof(uint8_t));
  181. +
  182. // Copy the bios32 code to a new address.
  183. uint32_t size = (uint32_t)BIOS32_END - (uint32_t)BIOS32_START;
  184. memcpy(newCodeBase, BIOS32_START, size);
  185.  
  186. - // Start executing the BIOS32 code.
  187. - bios32_execute();
  188. -
  189. - // Copy the output registers to the out ptr.
  190. - in_reg16_address = REBASE_ADDRESS(&bios32_out_reg16_ptr);
  191. - memcpy(out, in_reg16_address, sizeof(REGISTERS_16));
  192. -
  193. - // Reinitialize GDT and IDT
  194. - gdtInit();
  195. - idtInit();
  196. -}
  197. \ No newline at end of file
  198. + // Start executing the BIOS32 code.
  199. + bios32_execute();
  200. +
  201. + // Copy the output registers to the out ptr.
  202. + in_reg16_address = REBASE_ADDRESS(&bios32_out_reg16_ptr);
  203. + memcpy(out, in_reg16_address, sizeof(REGISTERS_16));
  204. +}
  205. diff --git a/source/kernel/gdt.c b/source/kernel/gdt.c
  206. index f64818d..6b857a1 100644
  207. --- a/source/kernel/gdt.c
  208. +++ b/source/kernel/gdt.c
  209. @@ -30,19 +30,19 @@ void gdtSetGate(int32_t num, uint32_t base, uint32_t limit, uint8_t access, uint
  210.  
  211. gdtEntries[num].granularity |= gran & 0xF0;
  212. gdtEntries[num].access = access;
  213. -}
  214. -
  215. -
  216. -// gdtInit() - Initializes GDT and sets up all the pointers
  217. -void gdtInit() {
  218. - // Setup the gdtPtr to point to our gdtEntires
  219. - gdtPtr.limit = 0xFFFFF;
  220. - gdtPtr.base = (uint32_t)&gdtEntries;
  221. -
  222. - // Now setup the GDT entries
  223. - gdtSetGate(0, 0, 0, 0, 0); // Null segment
  224. - gdtSetGate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF); // Code segment
  225. - gdtSetGate(2, 0, 0xFFFFFFFF, 0x92, 0xCF); // Data segment
  226. +}
  227. +
  228. +
  229. +// gdtInit() - Initializes GDT and sets up all the pointers
  230. +void gdtInit() {
  231. + // Setup the gdtPtr to point to our gdtEntires
  232. + gdtPtr.limit = sizeof(gdtEntries)-1;
  233. + gdtPtr.base = (uint32_t)&gdtEntries;
  234. +
  235. + // Now setup the GDT entries
  236. + gdtSetGate(0, 0, 0, 0, 0); // Null segment
  237. + gdtSetGate(1, 0, 0xFFFFFFFF, 0x9A, 0xCF); // Code segment
  238. + gdtSetGate(2, 0, 0xFFFFFFFF, 0x92, 0xCF); // Data segment
  239. gdtSetGate(3, 0, 0xFFFFFFFF, 0xFA, 0xCF); // User mode code segment
  240. gdtSetGate(4, 0, 0xFFFFFFFF, 0xF2, 0xCF); // User mode data segment.
  241. tssWrite(5, 0x10, 0x0); // Task state segment
  242. diff --git a/source/kernel/idt.c b/source/kernel/idt.c
  243. index cd08c69..8ba087b 100644
  244. --- a/source/kernel/idt.c
  245. +++ b/source/kernel/idt.c
  246. @@ -31,23 +31,23 @@ int idtInstallIR(uint8_t i, uint8_t flags, uint16_t segmentSelector, uint32_t ba
  247. idtEntries[i].flags = flags;
  248.  
  249. return 0;
  250. -}
  251. -
  252. -
  253. -
  254. -void idtInit() {
  255. - // Setup the IDT pointer.
  256. - idtPtr.limit = sizeof(idtEntry_t) * 256 - 1;
  257. - idtPtr.base_addr = (uint32_t)idtEntries;
  258. -
  259. - // Clear IDT entries table.
  260. - memset(&idtEntries, 0, sizeof(idtEntry_t)*256);
  261. -
  262. - // Enable PIC manually, pic.c DOES NOT WORK.
  263. - outportb(0x20, 0x11);
  264. - outportb(0xA0, 0x11);
  265. - outportb(0x21, 0x20);
  266. - outportb(0xA1, 0x28);
  267. +}
  268. +
  269. +
  270. +
  271. +void idtInit() {
  272. + // Setup the IDT pointer.
  273. + idtPtr.limit = sizeof(idtEntries)-1;
  274. + idtPtr.base_addr = (uint32_t)idtEntries;
  275. +
  276. + // Clear IDT entries table.
  277. + memset(&idtEntries, 0, sizeof(idtEntries));
  278. +
  279. + // Enable PIC manually, pic.c DOES NOT WORK.
  280. + outportb(0x20, 0x11);
  281. + outportb(0xA0, 0x11);
  282. + outportb(0x21, 0x20);
  283. + outportb(0xA1, 0x28);
  284. outportb(0x21, 0x04);
  285. outportb(0xA1, 0x02);
  286. outportb(0x21, 0x01);
  287. @@ -56,10 +56,10 @@ void idtInit() {
  288. outportb(0xA1, 0x0);
  289.  
  290.  
  291. -
  292. - isrInstall(); // Install handlers
  293. -
  294. - install_idt((uint32_t)&idtPtr);
  295. -
  296. - return;
  297. -}
  298. \ No newline at end of file
  299. +
  300. + isrInstall(); // Install handlers
  301. +
  302. + install_idt((uint32_t)&idtPtr);
  303. +
  304. + return;
  305. +}
  306. diff --git a/source/kernel/libc/string.c b/source/kernel/libc/string.c
  307. index 4aeff5b..b9d759b 100644
  308. --- a/source/kernel/libc/string.c
  309. +++ b/source/kernel/libc/string.c
  310. @@ -56,19 +56,19 @@ void* memmove(void* destination, const void* source, size_t n) {
  311. return destination;
  312. }
  313.  
  314. -
  315. -// memset() - Set a buffer in memory to a given value.
  316. -// Three parameters - buffer, value, amount of times to set
  317. -
  318. -void* memset(void *buf, char c, size_t n) {
  319. - unsigned char *temp = (unsigned char *)buf;
  320. - for (; n != 0; n--) temp[n] = c;
  321. - return buf;
  322. -}
  323. -
  324. -// strlen() - Returns the length of a string(size_t)
  325. -// One parameter - str
  326. -int strlen(char *str) {
  327. +
  328. +// memset() - Set a buffer in memory to a given value.
  329. +// Three parameters - buffer, value, amount of times to set
  330. +
  331. +void* memset(void *buf, char c, size_t n) {
  332. + unsigned char *temp = (unsigned char *)buf;
  333. + for (; n != 0; n--) temp[n-1] = c;
  334. + return buf;
  335. +}
  336. +
  337. +// strlen() - Returns the length of a string(size_t)
  338. +// One parameter - str
  339. +int strlen(char *str) {
  340. int i = 0;
  341. while (*str++) {
  342. i++;
Advertisement
Add Comment
Please, Sign In to add comment
Advertisement
Public Pastes
Advertisement
We use cookies for various purposes including analytics. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy.  OK, I Understand
Not a member of Pastebin yet?
Sign Up, it unlocks many cool features!