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-rw-r--r--c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c454
1 files changed, 0 insertions, 454 deletions
diff --git a/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c b/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c
deleted file mode 100644
index 58c39c8c24..0000000000
--- a/c/src/lib/libbsp/i386/shared/realmode_int/realmode_int.c
+++ /dev/null
@@ -1,454 +0,0 @@
-/**
- * @file realmode_int.c
- *
- * @ingroup i386_shared
- *
- * @brief Real mode interrupt call implementation
- */
-
-/*
- * Copyright (c) 2014 - CTU in Prague
- * Jan Doležal ( dolezj21@fel.cvut.cz )
- *
- * The license and distribution terms for this file may be
- * found in the file LICENSE in this distribution or at
- * http://www.rtems.org/license/LICENSE.
- */
-
-#include <bsp/realmode_int.h>
-#include <string.h>
-#include <rtems/score/cpu.h>
-
-/*
- * offsets to \a i386_realmode_interrupt_registers declared in realmode_int.h
- * used in inline assmbler for better readability
- */
-#define IR_EAX_OFF "0x00"
-#define IR_EBX_OFF "0x04"
-#define IR_ECX_OFF "0x08"
-#define IR_EDX_OFF "0x0C"
-#define IR_ESI_OFF "0x10"
-#define IR_EDI_OFF "0x14"
-#define IR_DS_OFF "0x18"
-#define IR_ES_OFF "0x1A"
-#define IR_FS_OFF "0x1C"
-#define IR_GS_OFF "0x1E"
-
-/*
- * offsets to \a rm_int_regs_bkp_param
- */
-#define BKP_ESP_OFF "0x20"
-#define BKP_SS_OFF "0x24"
-#define BKP_DS_OFF "0x26"
-#define RM_ENTRY "0x28"
-#define PM_ENTRY "0x2C"
-
-/**
- * @brief parameters, results, backup values accessible in real mode
- *
- * @note Struct members not necessarily used in C. This serves also as
- * layout of memory and it is used within inline assembler.
- */
-typedef struct {
- i386_realmode_interrupt_registers inoutregs;
- /** spot for back up of protected mode stack pointer */
- uint32_t pm_esp_bkp;
- /** spot for back up of protected mode stack selector */
- uint16_t pm_ss_bkp;
- /** spot for back up of protected mode data selector */
- uint16_t ds_bkp;
- /** spot for setting up long indirect jump offset
- to real mode from 16bit protected mode */
- uint16_t rm_entry;
- /** spot for setting up long indirect jump segment
- to real mode from 16bit protected mode */
- uint16_t rm_code_segment;
- /** returning offset for long indirect jump back
- to 32bit protected mode */
- uint32_t pm_entry;
- /** returning selector for long indirect jump back
- to 32bit protected mode */
- uint16_t pm_code_selector;
- /* if this struct is to be modified update offset definitions as well */
-} RTEMS_PACKED rm_int_regs_bkp_param;
-
-/* offsets to \a pm_bkp_and_param */
-#define BKP_IDTR_LIM "0x00"
-#define BKP_IDTR_BASE "0x02"
-#define BKP_ES_OFF "0x06"
-#define BKP_FS_OFF "0x08"
-#define BKP_GS_OFF "0x0A"
-#define RML_ENTRY "0x0C"
-#define RML_D_SEL "0x12"
-#define RM_SS "0x14"
-#define RM_SP "0x16"
-#define RM_DS "0x18"
-
-/**
- * @brief backup values, pointers/parameters accessible in protected mode
- *
- * @note Struct members not necessarily used in C. This serves also as
- * layout of memory and it is used within inline assembler.
- */
-typedef struct {
- /** spot for backup protected mode interrupt descriptor table register */
- uint16_t idtr_lim_bkp;
- /** @see idtr_lim_bkp */
- uint32_t idtr_base_bkp;
- /** spot to backup of ES register value in 32bit protected mode */
- uint16_t es_bkp;
- /** spot to backup of FS register value in 32bit protected mode */
- uint16_t fs_bkp;
- /** spot to backup of GS register value in 32bit protected mode */
- uint16_t gs_bkp;
- /** values for indirect jump to 16bit protected mode */
- uint32_t rml_entry;
- /** @see rml_entry */
- uint16_t rml_code_selector;
- /** data selector for 16bit protected mode */
- uint16_t rml_data_selector;
- /** values determinig location of real mode stack */
- uint16_t rm_stack_segment;
- /** @see rm_stack_segment */
- uint16_t rm_stack_pointer;
- /** data segment for real mode */
- uint16_t rm_data_segment;
-} RTEMS_PACKED pm_bkp_and_param;
-
-/* addresses where we are going to put Interrupt buffer,
- * parameter/returned/preserved values, stack and copy code
- * for calling BIOS interrupt real mode interface
- * The value is chosen arbitrarily in the first 640kB
- * to be accessible for real mode. It should be out of range
- * used by RTEMS because its base address is above 1MB.
- * It has to be above first 4kB (or better 64kB) which could
- * be used by BIOS.
- */
-#define REAL_MODE_SPOT 0x12000
-/* REAL_MODE_SPOT value is also top of real mode stack */
-
-/* buffers positions and lengths */
-#define DEFAULT_BUFFER_SIZE 512
-static void *default_rm_buffer_spot = (void *)REAL_MODE_SPOT;
-static uint16_t default_rm_buffer_size = DEFAULT_BUFFER_SIZE;
-
-/* real mode stack */
-#define STACK_SIZE 8192
-#define INT_STACK_TOP REAL_MODE_SPOT
-
-/******************************
- * STACK * *
- ****************************** REAL_MODE_SPOT
- * INT_BUF * 512 B *
- ******************************
- * INT_REGs * 50 B *
- ******************************
- * INT_FNC *~149 B *
- ******************************/
-
-#define __DP_TYPE uint8_t
-#define __DP_YES ((__DP_TYPE)1)
-#define __DP_NO ((__DP_TYPE)-1)
-#define __DP_FAIL ((__DP_TYPE)0)
-static __DP_TYPE descsPrepared = __DP_NO;
-
-/* rml - real mode alike */
-#define rml_limit 0xFFFF
-static uint16_t rml_code_dsc_index = 0;
-static uint16_t rml_data_dsc_index = 0;
-
-/**
- * @brief Prepares real-mode like descriptors to be used for switching
- * to real mode.
- *
- * Descriptors will be placed to the GDT.
- *
- * @param[in] base32 32-bit physical address to be used as base for 16-bit
- * protected mode descriptors
- * @retval __DP_YES descriptors are prepared
- * @retval __DP_FAIL descriptors allocation failed (GDT too small)
- */
-static __DP_TYPE prepareRMDescriptors (void *base32) {
- static void *prevBase = (void *)-1;
- /* check if descriptors were prepared already */
- if (descsPrepared == __DP_YES && prevBase == base32)
- return descsPrepared;
-
- if (descsPrepared == __DP_FAIL)
- return descsPrepared;
-
- /* create 'real mode like' segment descriptors, for switching to real mode */
- rml_code_dsc_index = i386_next_empty_gdt_entry();
- if (rml_code_dsc_index == 0)
- {
- /* not enough space in GDT */
- descsPrepared = __DP_FAIL;
- return descsPrepared;
- }
-
- segment_descriptors flags_desc;
- memset(&flags_desc, 0, sizeof(flags_desc));
- flags_desc.type = 0xE; /* bits 4 */
- flags_desc.descriptor_type = 0x1; /* bits 1 */
- flags_desc.privilege = 0x0; /* bits 2 */
- flags_desc.present = 0x1; /* bits 1 */
- flags_desc.available = 0x0; /* bits 1 */
- flags_desc.fixed_value_bits = 0x0; /* bits 1 */
- flags_desc.operation_size = 0x0; /* bits 1 */
- flags_desc.granularity = 0x0; /* bits 1 */
- i386_fill_segment_desc_base((unsigned)base32, &flags_desc);
- i386_fill_segment_desc_limit(rml_limit, &flags_desc);
- if (i386_raw_gdt_entry(rml_code_dsc_index, &flags_desc) == 0)
- {
- /* selector to GDT out of range */
- descsPrepared = __DP_FAIL;
- return descsPrepared;
- }
-
- rml_data_dsc_index = i386_next_empty_gdt_entry();
- if (rml_data_dsc_index == 0)
- {
- /* not enough space in GDT for both descriptors */
- descsPrepared = __DP_FAIL;
- return descsPrepared;
- }
-
- flags_desc.type = 0x2; /* bits 4 */
- if (i386_raw_gdt_entry(rml_data_dsc_index, &flags_desc) == 0)
- {
- /* selector to GDT out of range */
- descsPrepared = __DP_FAIL;
- return descsPrepared;
- }
- prevBase = base32;
- descsPrepared = __DP_YES;
- return descsPrepared;
-}
-
-void *i386_get_default_rm_buffer(uint16_t *size) {
- *size = default_rm_buffer_size;
- return default_rm_buffer_spot;
-}
-
-int i386_real_interrupt_call(uint8_t interrupt_number,
- i386_realmode_interrupt_registers *ir)
-{
- uint32_t pagingon;
- rm_int_regs_bkp_param *int_passed_regs_spot;
- /* place where the code switching to realmode and executing
- interrupt is coppied */
- void *rm_swtch_code_dst;
- void *rm_stack_top;
-
- size_t cpLength;
- void *cpBeg;
-
- /* values that can be passed from protected mode are stored in this struct
- and they are passed later to the inline assembler executing interrupt */
- volatile pm_bkp_and_param pm_bkp, *pm_bkp_addr;
- unsigned short unused_offset;
-
- __asm__ volatile( "\t"
- "movl %%cr0, %%eax\n\t"
- "andl %1, %%eax\n"
- : "=a"(pagingon)
- : "i"(CR0_PAGING)
- );
- if (pagingon)
- return 0;
-
- /* located under 1MB for real mode to be able to get/set values */
- int_passed_regs_spot = (rm_int_regs_bkp_param *)
- (default_rm_buffer_spot+default_rm_buffer_size);
- /* position for real mode code reallocation to the first 1MB of RAM */
- rm_swtch_code_dst = (void *)((uint32_t)int_passed_regs_spot +
- sizeof(*int_passed_regs_spot));
- rm_stack_top = (void *)INT_STACK_TOP;
-
- if (prepareRMDescriptors(int_passed_regs_spot) != __DP_YES)
- return 0;
-
- pm_bkp_addr = &pm_bkp;
- i386_Physical_to_real(
- rm_stack_top - STACK_SIZE,
- (unsigned short *)&pm_bkp.rm_stack_segment,
- (unsigned short *)&pm_bkp.rm_stack_pointer
- );
- pm_bkp.rm_stack_pointer += STACK_SIZE;
- pm_bkp.rml_code_selector = (rml_code_dsc_index<<3);
- pm_bkp.rml_entry = ((uint32_t)rm_swtch_code_dst -
- (uint32_t)int_passed_regs_spot);
- pm_bkp.rml_data_selector = (rml_data_dsc_index<<3);
- i386_Physical_to_real(
- int_passed_regs_spot,
- (unsigned short *)&pm_bkp.rm_data_segment,
- &unused_offset
- );
-
- int_passed_regs_spot->inoutregs = *ir;
- /* offset from the beginning of coppied code */
- uint16_t rm_entry_offset;
- __asm__ volatile(
- "movw $(rment-cp_beg), %0\n\t"
- : "=r"(rm_entry_offset)
- );
- i386_Physical_to_real(
- rm_swtch_code_dst+rm_entry_offset,
- (unsigned short *)&int_passed_regs_spot->rm_code_segment,
- (unsigned short *)&int_passed_regs_spot->rm_entry
- );
- __asm__ volatile(
- "movl $(cp_end), %0\n\t"
- "movw %%cs, %1\n\t"
- : "=mr"(int_passed_regs_spot->pm_entry),
- "=mr"(int_passed_regs_spot->pm_code_selector)
- );
- /* copy code for switch to real mode and
- executing interrupt to first MB of RAM */
- __asm__ volatile( "\t"
- "mov $cp_end-cp_beg, %0\n\t"
- "mov $cp_beg, %1\n\t"
- : "=rm"(cpLength), "=rm"(cpBeg)
- );
- memcpy(rm_swtch_code_dst, cpBeg, cpLength);
- /* write interrupt number to be executed */
- uint16_t interrupt_number_off;
- uint8_t *interrupt_number_ptr;
- __asm__ volatile( "\t"
- "movw $intnum-cp_beg, %0\n\t"
- : "=rm"(interrupt_number_off)
- );
- interrupt_number_ptr = (uint8_t *)(rm_swtch_code_dst+interrupt_number_off);
- *interrupt_number_ptr = interrupt_number;
- /* execute code that jumps to coppied function, which switches to real mode,
- loads registers with values passed to interrupt and executes interrupt */
- __asm__ volatile( "\t"
- /* backup stack */
- "movl %[regs_spot], %%ebx\n\t"
- "movl %%esp, "BKP_ESP_OFF"(%%ebx)\n\t"
- "movw %%ss, "BKP_SS_OFF"(%%ebx)\n\t"
- /* backup data selector */
- "movw %%ds, "BKP_DS_OFF"(%%ebx)\n\t"
- /* backup other selectors */
- "movl %[pm_bkp], %%esi\n\t"
- "movw %%es, "BKP_ES_OFF"(%%esi)\n\t"
- "movw %%fs, "BKP_FS_OFF"(%%esi)\n\t"
- "movw %%gs, "BKP_GS_OFF"(%%esi)\n\t"
- /* hopefully loader does not damage interrupt table on the beginning of
- memory; that means length: 0x3FF, base: 0x0 */
- /* preserve idtr */
- "movl %%esi, %%eax\n\t"
- "addl $"BKP_IDTR_LIM", %%eax\n\t"
- "cli\n\t"
- "sidt (%%eax)\n\t"
- "movl $rmidt, %%eax\n\t"
- "lidt (%%eax)\n\t"
- /* prepare 'real mode like' data selector */
- "movw "RML_D_SEL"(%%esi), %%ax\n\t"
- /* prepare real mode data segment value */
- "xorl %%edx,%%edx\n\t"
- "movw "RM_DS"(%%esi), %%dx\n\t"
- /* prepare real mode stack values */
- "movw "RM_SS"(%%esi), %%cx\n\t"
- "movzwl "RM_SP"(%%esi), %%esp\n\t"
- /* jump to copied function and */
- /* load 'real mode like' code selector */
- "ljmp *"RML_ENTRY"(%%esi)\n"
-"rmidt:"/* limit and base for realmode interrupt descriptor table */
- ".word 0x3FF\n\t"
- ".long 0\n\t"
- /* load 'real mode like' data selectors */
-"cp_beg: .code16\n\t"
- "movw %%ax, %%ss\n\t"
- "movw %%ax, %%ds\n\t"
- "movw %%ax, %%es\n\t"
- "movw %%ax, %%fs\n\t"
- "movw %%ax, %%gs\n\t"
- /* disable protected mode */
- "movl %%cr0, %%eax\n\t"
- "and %[cr0_prot_dis], %%ax\n\t"
- "movl %%eax, %%cr0\n\t"
- /* base for data selector of 16-bit protected mode is
- at beginning of passed regs */
- /* flush prefetch queue by far jumping */
- "ljmp *"RM_ENTRY"\n\t"
-"rment: "
- /* establish rm stack - esp was already set in 32-bit protected mode*/
- "movw %%cx, %%ss\n\t"
- /* set data segment (value prepared in 32-bit prot mode) */
- "movw %%dx, %%ds\n\t"
- /* count real mode pointer so we don't need to overuse address
- prefix (by using 32bit addresses in 16bit context) */
- "shll $4,%%edx\n\t"
- "subl %%edx,%%ebx\n\t"
- /* prepare values to be used after interrupt call */
- "pushw %%bx\n\t"
- "pushw %%ds\n\t"
- /* fill registers with parameters */
- "movw " IR_DS_OFF"(%%bx), %%ax\n\t"
- "pushw %%ax\n\t"
- "movl "IR_EAX_OFF"(%%bx), %%eax\n\t"
- "movl "IR_ECX_OFF"(%%bx), %%ecx\n\t"
- "movl "IR_EDX_OFF"(%%bx), %%edx\n\t"
- "movl "IR_EDI_OFF"(%%bx), %%edi\n\t"
- "movl "IR_ESI_OFF"(%%bx), %%esi\n\t"
- "movw " IR_ES_OFF"(%%bx), %%es\n\t"
- "movw " IR_FS_OFF"(%%bx), %%fs\n\t"
- "movw " IR_GS_OFF"(%%bx), %%gs\n\t"
- /* prepare ebx register */
- "movl "IR_EBX_OFF"(%%bx), %%ebx\n\t"
- /* prepare ds */
- "popw %%ds\n\t"
- /* interrupt instruction */
- ".byte 0xCD\n\t"
-"intnum: .byte 0x0\n\t"
- /* fill return structure */
- "pushw %%ds\n\t"
- "pushl %%ebx\n\t"
- "movw 0x6(%%esp), %%ds\n\t"
- "movw 0x8(%%esp),%%bx\n\t" /* regs_spot */
- "movl %%eax,"IR_EAX_OFF"(%%bx)\n\t"
- "popl %%eax\n\t"
- "movl %%eax,"IR_EBX_OFF"(%%bx)\n\t"
- "movl %%ecx,"IR_ECX_OFF"(%%bx)\n\t"
- "movl %%edx,"IR_EDX_OFF"(%%bx)\n\t"
- "movl %%esi,"IR_ESI_OFF"(%%bx)\n\t"
- "movl %%edi,"IR_EDI_OFF"(%%bx)\n\t"
- "popw %%ax\n\t"
- "movw %%ax, " IR_DS_OFF"(%%bx)\n\t"
- "movw %%es, " IR_ES_OFF"(%%bx)\n\t"
- "movw %%fs, " IR_FS_OFF"(%%bx)\n\t"
- "movw %%gs, " IR_GS_OFF"(%%bx)\n\t"
- /* prepare protected mode data segment */
- "movw "BKP_DS_OFF"(%%bx), %%ax\n\t"
- /* restore protected mode stack values */
- "movl "BKP_ESP_OFF"(%%bx),%%esp\n\t"
- "movw "BKP_SS_OFF"(%%bx), %%dx\n\t"
- /* return to protected mode */
- "movl %%cr0, %%ecx \n\t"
- "or %[cr0_prot_ena], %%cx\n\t"
- "movl %%ecx, %%cr0 \n\t"
- "ljmpl *"PM_ENTRY"(%%bx)\n\t"
- ".code32\n"
- /* reload segmentation registers */
-"cp_end:"
- "movw %%ax, %%ds\n\t"
- /* restore stack segment in protected mode context */
- "movw %%dx, %%ss\n\t"
- "movl %[pm_bkp], %%esi\n\t"
- "movw "BKP_ES_OFF"(%%esi), %%es\n\t"
- "movw "BKP_FS_OFF"(%%esi), %%fs\n\t"
- "movw "BKP_GS_OFF"(%%esi), %%gs\n\t"
- /* restore IDTR */
- "addl $"BKP_IDTR_LIM", %%esi\n\t"
- "lidt (%%esi)\n\t"
- :
- : [regs_spot]"m"(int_passed_regs_spot),
- [pm_bkp]"m"(pm_bkp_addr),
- [cr0_prot_ena]"i"(CR0_PROTECTION_ENABLE),
- [cr0_prot_dis]"i"(~CR0_PROTECTION_ENABLE)
- : "memory", "ebx", "ecx", "edx", "esi", "edi"
- );
- *ir = int_passed_regs_spot->inoutregs;
- return 1;
-}
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-27 17:37:38 +0000