diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | atags.c | 99 | ||||
| -rw-r--r-- | atags.h | 102 | ||||
| -rw-r--r-- | setup.c | 14 |
4 files changed, 213 insertions, 4 deletions
@@ -3,7 +3,7 @@ ELFFLAGS=-nostdlib -lgcc ARM_OBJECTS=kernel.o paging.o demo_functionality.o PL0_test.o uart.o loader_stage1.o loader_stage2.o -KERNEL_STAGE2_OBJECTS=setup.o interrupt_vector.o interrupts.o uart.o demo_functionality.o paging.o ramfs_embeddable.o ramfs.o strings.o io.o +KERNEL_STAGE2_OBJECTS=setup.o interrupt_vector.o interrupts.o uart.o demo_functionality.o paging.o ramfs_embeddable.o ramfs.o strings.o io.o atags.o PL_0_TEST_OBJECTS=PL0_utils.o svc.o PL0_test.o strings.o io.o @@ -0,0 +1,99 @@ +#include "atags.h" +#include "io.h" + +static inline struct atag_header *next_tag(struct atag_header *tag) +{ + return (struct atag_header*) (((uint32_t*) tag) + tag->size); +} + +#define TAG_CONTENTS_FUN(tagname) \ + static inline struct atag_##tagname *tagname##_tag_contents \ + (struct atag_header *tag) \ + { \ + return (struct atag_##tagname*) (tag + 1); \ + } + +TAG_CONTENTS_FUN(header) +TAG_CONTENTS_FUN(core) +TAG_CONTENTS_FUN(mem) +TAG_CONTENTS_FUN(videotext) +TAG_CONTENTS_FUN(ramdisk) +TAG_CONTENTS_FUN(initrd2) +TAG_CONTENTS_FUN(serialnr) +TAG_CONTENTS_FUN(revision) +TAG_CONTENTS_FUN(videolfb) +TAG_CONTENTS_FUN(cmdline) + +uint32_t find_memory_size(struct atag_header *atags) +{ + // we silently assume there will only be one mem atag + while (atags->tag != ATAG_MEM && atags->tag != ATAG_NONE) + atags = next_tag(atags); + + if (atags->tag == ATAG_NONE) + return 0; + + struct atag_mem *mem_tag = mem_tag_contents(atags); + + // our design assumes address 0x0 is available, so we reject mem + // atag saying otherwise + if (mem_tag->start != 0) + return 0; + + return mem_tag->size; +} + +void print_tag(struct atag_header *tag) +{ +#define TAG_CASE(tagname_upcase, tagname_locase, instructions) \ + case ATAG_##tagname_upcase: \ + puts("ATAG_" #tagname_upcase ":"); \ + { \ + struct atag_##tagname_locase *contents = \ + tagname_locase##_tag_contents(tag); \ + instructions; \ + } \ + break + + switch (tag->tag) + { + TAG_CASE(CORE, core, + prints(" flags: 0x"); + printhex(contents->flags); puts(""); + prints(" page size: "); + printdec(contents->pagesize); puts(""); + prints(" root device: "); + printdec(contents->rootdev); puts("");); + TAG_CASE(MEM, mem, + prints(" memory size: 0x"); + printhex(contents->size); puts(""); + prints(" memory start: 0x"); + printhex(contents->start); puts("");); + // the rest are unimportant for now, + // as they're not passed by qemu + TAG_CASE(VIDEOTEXT, videotext, (void) contents;); + TAG_CASE(RAMDISK, ramdisk, (void) contents;); + TAG_CASE(INITRD2, initrd2, (void) contents;); + TAG_CASE(SERIAL, serialnr, (void) contents;); + TAG_CASE(REVISION, revision, (void) contents;); + TAG_CASE(VIDEOLFB, videolfb, (void) contents;); + TAG_CASE(CMDLINE, cmdline, (void) contents;); + + case ATAG_NONE: + puts("ATAG_NONE"); + break; + default: + prints("!! unknown tag: 0x"); printhex(tag->tag); puts(" !!"); + } +} + +void print_atags(struct atag_header *atags) +{ + while (atags->tag != ATAG_NONE) + { + print_tag(atags); + atags = next_tag(atags); + } + + print_tag(atags); // also print ATAG_NONE +} @@ -0,0 +1,102 @@ +#ifndef ATAGS_H +#define ATAGS_H + +#include <stdint.h> + +#define ATAG_NONE 0x00000000 +#define ATAG_CORE 0x54410001 +#define ATAG_MEM 0x54410002 +#define ATAG_VIDEOTEXT 0x54410003 +#define ATAG_RAMDISK 0x54410004 +#define ATAG_INITRD2 0x54420005 +#define ATAG_SERIAL 0x54410006 +#define ATAG_REVISION 0x54410007 +#define ATAG_VIDEOLFB 0x54410008 +#define ATAG_CMDLINE 0x54410009 + +struct atag_header +{ + uint32_t size; + uint32_t tag; +}; + +struct atag_core +{ + uint32_t flags; + uint32_t pagesize; + uint32_t rootdev; +}; + +struct atag_mem +{ + uint32_t size; + uint32_t start; +}; + +struct atag_videotext +{ + uint8_t x; + uint8_t y; + uint16_t video_page; + uint8_t video_mode; + uint8_t video_cols; + uint16_t video_ega_bx; + uint8_t video_lines; + uint8_t video_isvga; + uint16_t video_points; +}; + +struct atag_ramdisk +{ + uint32_t flags; + uint32_t size; + uint32_t start; +}; + +struct atag_initrd2 +{ + uint32_t start; + uint32_t size; +}; + +struct atag_serialnr +{ + uint32_t low; + uint32_t high; +}; + +struct atag_revision +{ + uint32_t rev; +}; + +struct atag_videolfb +{ + uint16_t lfb_width; + uint16_t lfb_height; + uint16_t lfb_depth; + uint16_t lfb_linelength; + uint32_t lfb_base; + uint32_t lfb_size; + uint8_t red_size; + uint8_t red_pos; + uint8_t green_size; + uint8_t green_pos; + uint8_t blue_size; + uint8_t blue_pos; + uint8_t rsvd_size; + uint8_t rsvd_pos; +}; + +struct atag_cmdline +{ + char cmdline[1]; +}; + +uint32_t find_memory_size(struct atag_header *atags); + +void print_tag(struct atag_header *tag); + +void print_atags(struct atag_header *atags); + +#endif // ATAGS_H @@ -2,9 +2,10 @@ #include "io.h" #include "demo_functionality.h" #include "paging.h" +#include "atags.h" void setup(uint32_t r0, uint32_t machine_type, - uint32_t atags) + struct atag_header *atags) { uart_init(); @@ -17,12 +18,19 @@ void setup(uint32_t r0, uint32_t machine_type, prints("ARM machine type: 0x"); printhext(machine_type); puts(""); - // value 3 introduced by stage1 code, means no atags was found + // value 3 introduced by stage1 code means no atags was found if (r0 == 3) puts("No ATAGS was found!"); else { - prints("ATAGS copied to 0x"); printhex(atags); puts(""); + prints("ATAGS copied to 0x"); + printhex((uint32_t) atags); puts(""); + + puts("__ ATAGS contents __"); + + print_atags(atags); + + puts("__ end of ATAGS contents __"); } // prints some info |