On Wed, Nov 12, 2014 at 10:07 AM, Jan Dolezal <dolez...@fel.cvut.cz> wrote: > --- > c/src/lib/libbsp/i386/pc386/Makefile.am | 2 + > c/src/lib/libbsp/i386/pc386/preinstall.am | 4 + > c/src/lib/libbsp/i386/shared/int16/int16.c | 397 > +++++++++++++++++++++++++++++ > c/src/lib/libbsp/i386/shared/int16/int16.h | 93 +++++++ > 4 files changed, 496 insertions(+) > create mode 100644 c/src/lib/libbsp/i386/shared/int16/int16.c > create mode 100644 c/src/lib/libbsp/i386/shared/int16/int16.h These new files should probably go under i386/shared/irq ?
> > diff --git a/c/src/lib/libbsp/i386/pc386/Makefile.am > b/c/src/lib/libbsp/i386/pc386/Makefile.am > index 9c901df..6042b5b 100644 > --- a/c/src/lib/libbsp/i386/pc386/Makefile.am > +++ b/c/src/lib/libbsp/i386/pc386/Makefile.am > @@ -29,6 +29,7 @@ SUBDIRS = . tools > include_bsp_HEADERS = ../../i386/shared/irq/irq.h > include_bsp_HEADERS += ../../i386/shared/irq/irq_asm.h > include_bsp_HEADERS += ../../i386/shared/comm/tty_drv.h > +include_bsp_HEADERS += ../../i386/shared/int16/int16.h > include_bsp_HEADERS += ../../shared/include/irq-generic.h > include_bsp_HEADERS += ../../shared/include/irq-info.h > include_bsp_HEADERS += console/rtd316.h > @@ -94,6 +95,7 @@ libbsp_a_SOURCES += console/kbd_parser.c > libbsp_a_SOURCES += console/serial_mouse_config.c > libbsp_a_SOURCES += ../../i386/shared/comm/uart.c > libbsp_a_SOURCES += ../../i386/shared/comm/tty_drv.c > +libbsp_a_SOURCES += ../../i386/shared/int16/int16.c > libbsp_a_SOURCES += ../../shared/console.c > libbsp_a_SOURCES += console/console_select.c > libbsp_a_SOURCES += ../../shared/console_read.c > diff --git a/c/src/lib/libbsp/i386/pc386/preinstall.am > b/c/src/lib/libbsp/i386/pc386/preinstall.am > index aff01dc..1ff9fb8 100644 > --- a/c/src/lib/libbsp/i386/pc386/preinstall.am > +++ b/c/src/lib/libbsp/i386/pc386/preinstall.am > @@ -69,6 +69,10 @@ $(PROJECT_INCLUDE)/bsp/tty_drv.h: > ../../i386/shared/comm/tty_drv.h $(PROJECT_INC > $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/tty_drv.h > PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/tty_drv.h > > +$(PROJECT_INCLUDE)/bsp/int16.h: ../../i386/shared/int16/int16.h > $(PROJECT_INCLUDE)/bsp/$(dirstamp) > + $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/int16.h > +PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/int16.h > + > $(PROJECT_INCLUDE)/bsp/irq-generic.h: ../../shared/include/irq-generic.h > $(PROJECT_INCLUDE)/bsp/$(dirstamp) > $(INSTALL_DATA) $< $(PROJECT_INCLUDE)/bsp/irq-generic.h > PREINSTALL_FILES += $(PROJECT_INCLUDE)/bsp/irq-generic.h > diff --git a/c/src/lib/libbsp/i386/shared/int16/int16.c > b/c/src/lib/libbsp/i386/shared/int16/int16.c > new file mode 100644 > index 0000000..380188f > --- /dev/null > +++ b/c/src/lib/libbsp/i386/shared/int16/int16.c > @@ -0,0 +1,397 @@ > +/* > + * Realmode interrupt call implementation. > + * > + * > + * Copyright (c) 2014 - CTU in Prague > + * Jan Doležal ( dolez...@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/int16.h> > +#include <string.h> Why include string.h? I have more comments below in the .h file. I am not reviewing this .c file due to time constraints and my lack of confidence in x86 assembly, but I will say if the below macros and struct defines are useful outside this file, then they should go into a header file instead. Also, I think we use __volatile__ for declaring ASM blocks. (We ought to have an RTEMS macro for this, e.g. RTEMS_INLINE_ASM(), but I don't think we do.) > +#include <rtems/score/cpu.h> > + > +#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" > + > +#define BKP_ESP_OFF "0x20" > +#define BKP_SS_OFF "0x24" > +#define BKP_DS_OFF "0x26" > +#define RM_ENTRY "0x28" > +#define PM_ENTRY "0x2C" > + > +/* parameters, results, backup values accessible in real mode */ > +struct rm_int_regs_bkp_param { > + struct interrupt_registers inoutregs; > + uint32_t pm_esp_bkp; > + uint16_t pm_ss_bkp; > + uint16_t ds_bkp; > + uint16_t rm_entry; > + uint16_t rm_code_segment; > + uint32_t pm_entry; > + uint16_t pm_code_selector; > + /* if modifying update offset definitions as well */ > +}__attribute__((__packed__)); > + > +#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" > +/* backup values, pointers/parameters accessible in protected mode */ > +struct pm_bkp_and_param { > + uint16_t idtr_lim_bkp; > + uint32_t idtr_base_bkp; > + uint16_t es_bkp; > + uint16_t fs_bkp; > + uint16_t gs_bkp; > + uint32_t rml_entry; > + uint16_t rml_code_selector; > + uint16_t rml_data_selector; > + uint16_t rm_stack_segment; > + uint16_t rm_stack_pointer; > + uint16_t rm_data_segment; > +}__attribute__((__packed__)); > + > +/* 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 *first_rm_buffer_spot = (void *)REAL_MODE_SPOT; > +static uint16_t first_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; > + > +/* > + * Prepares real-mode like descriptors to be used for switching > + * to real mode. > + * > + * @return __DP_YES descriptors are prepared > + * @return __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; > +} > + > +inline void *i386_get_primary_rm_buffer() { > + return first_rm_buffer_spot; > +} > + > +inline uint16_t i386_get_primary_rm_buffer_size() { > + return first_rm_buffer_size; > +} > + > +int i386_real_interrupt_call(uint8_t interruptNumber, struct > interrupt_registers *ir){ > + uint32_t pagingon; > + struct 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 struct 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 = (struct rm_int_regs_bkp_param *) > + (first_rm_buffer_spot+first_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_mode_ptr( > + 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_mode_ptr( > + 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_mode_ptr( > + 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 = interruptNumber; > + /* 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 address) */ > + "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; > +} > + > diff --git a/c/src/lib/libbsp/i386/shared/int16/int16.h > b/c/src/lib/libbsp/i386/shared/int16/int16.h > new file mode 100644 > index 0000000..96025ef > --- /dev/null > +++ b/c/src/lib/libbsp/i386/shared/int16/int16.h > @@ -0,0 +1,93 @@ > +/** > + * @file int16.h > + * > + * @ingroup i386_shared > + * > + * @brief Definitioins supporting real mode interrupt calls. > + */ > + > +/* > + * Interface allows calling given interrupt number with content of the > + * registers defined. For passing or receiving higher amounts of the data > + * there is a buffer accessible from real mode available. Real mode pointer > + * to this buffer is passed to the interrupt in the registers. > + * > + * Copyright (C) 2014 Jan Doležal (dolez...@fel.cvut.cz) > + * CTU in Prague. > + * > + * 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. > + */ > + > +#ifndef _INT16_H > +#define _INT16_H > + > +#include <libcpu/cpu.h> > +#include <stdint.h> > + > +#ifndef ASM /* ASM */ > + > +#ifdef __cplusplus > +extern "C" { > +#endif /* __cplusplus */ > + > +/* --- BIOS service interrupt number --- */ > +/* number of interrupt servicing video functions */ > +#define INTERRUPT_NO_VIDEO_SERVICES 0x10 > + > +struct interrupt_registers { /* used for passing parameters, fetching > results and preserving values */ > + uint32_t reg_eax; > + uint32_t reg_ebx; > + uint32_t reg_ecx; > + uint32_t reg_edx; > + uint32_t reg_esi; > + uint32_t reg_edi; > + uint16_t reg_ds; > + uint16_t reg_es; > + uint16_t reg_fs; > + uint16_t reg_gs; > +}__attribute__((__packed__)); > + RTEMS prefers to use typedef on struct names. Also, the name should be "namespaced", for example, i386_interrupt_registers. Usually I would expect to see this kind of structure in score/cpu/i386/rtems/score/i386.h defined as an interrupt context structure. I think ARM has an example. Is __packed__ necessary? We avoid compiler attributes where possible, and where necessary we should use a macro e.g. RTEMS_PACKED_STRUCT (or something, if it exists). > +/** > + * provides position to real mode buffer, which is buffer > + * accessible from real mode context - it is located below > + * address ~0x100000 in order for it to be accessible > + * This buffer is meant to be pointed to by segReg:GenPurpReg > + * and through this get bigger portion of information to/from > + * interrupt service routine. > + * > + * @return pointer to buffer > + */ > +extern void *i386_get_primary_rm_buffer(void); > + avoid abbreviations, use realmode What does "primary" mean? Is there a "secondary"? If not, just use i386_get_realmode_buffer(). > +/** > + * returns size of real mode buffer > + * > + * @return size of buffer > + */ > +extern uint16_t i386_get_primary_rm_buffer_size(void); > + The above two functions can be merged together, where the buffer is returned and the size gets set as a side-effect, if that is useful. > +/* if there is ever need to have more buffers or setting size of the buffer, > + * feel free to modify the code */ > + > +/** > + * This function allows calling interrupts in real mode and to set processor > + * registers as desired before interrupt call is made and to retrieve the > + * registers content after call was made. > + * > + * @param interruptNumber interrupt number to be called > + * @param ir pointer to structure containing registers to be passed to > interrupt > + * and to retrieve register content after call was made. > + * @return 0 call failed (GDT too small or pagin is on) > + * 1 call successful > + */ > +extern int i386_real_interrupt_call(uint8_t interruptNumber, struct > interrupt_registers *ir); > + > +#ifdef __cplusplus > +} > +#endif /* __cplusplus */ > + > +#endif /* ASM */ > + > +#endif /* _INT16_H */ > -- > 1.9.1 > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel _______________________________________________ devel mailing list devel@rtems.org http://lists.rtems.org/mailman/listinfo/devel